Occasionedby the suggestion of Sandel that it may sometimes be morally permissible todeceive people, so long as you do so without lying, I here examine such allegedtruths as “I did not have sexual relations with that woman.”After setting up the issues in Section 1, in Sections 2-4 I examine questions of language, communication, and truthfulnessin assessing whether candidate deceptive truths really are true. Thesesections require little if any prior familiarity in the area. The fifthsection, however, probably will be hard to follow unless you have some acquaintancewith Kant’s ethics. Lacking that, you still may well be able to follow theSections 6-8, and the final section on the Clinton impeachment has noprerequisites.
Kantfamously held that it is never morally permissible to lie. When the murdererturns up at your door searching for the friend you are harboring in your house,you may not say, “She just ran down the alley.” Benjamin Constant came up withthe murderer at the door as a counterexample to Kant’s absolute prohibition onlying, but Kant doubled down, embracing prohibition even in this extreme case(“On a Supposed Right to Lie from Philanthropy.”) This may have been a mistakeon Kant’s part. At least, as I will argue later, Kant’s moral theory may wellhave the resources for providing a more palatable response to murderers at yourdoor.
Get an answer for 'Why does Kant consider lying wrong? What is wrong with Kant's ethics when applied to the murderer at the door example?' And find homework help for other Kant, Immanuel questions.
My chiefpurpose here, however, is not to join the legion of Kant scholars, all of them moreKant-knowledgeable than I, who have tried to improve upon what Kant said about thisfamous case. My focus, instead, is ondeceptive truth telling – sometimes suggested as a tactic for doorstepmurderers. In particular I am concerned with these questions: What aredeceptive truths like and how common are they? Would Kant have made a moraldistinction between lying and deceiving by saying something true, and if so,what sort of distinction? How should we evaluate the morality of deceptivetruths, and, in particular, how do they stack up against lies?
- Sandel on Kant on Deceptive Truth
Sandel, inthe 7th video episode of his enormously popular Harvard course (http://www.justiceharvard.org/2011/02/episode-07/#watch)suggests that Kant might be OK with a deceptive truthful statement to themurderer at the door. Perhaps, having told your friend to pick someplace tohide in your house, you say “I don't know where she is.” This would be truthful,says a student with Sandel’s apparent concurrence, because you have in yourmind a sense in which you believe it to be true. You don't know where in yourhouse your friend is hiding. (lecture 12:42 – 14:05) She might be in the basementski locker and she might be up on the widow’s walk or under the billiard table.You would not have said what you did, had you not recognized the sense in whichit was true. In fact, you hit upon it, by thinking “what can I say that is truebut will probably save my friend.” So the moral law, which requirestruthfulness, controlled your choice. You acted, in that respect, out ofobligation.
Many relevanttruths, of course, would have been friend-unhelpful. This one, however, mightprotect your friend by deceiving the murderer. In particular, you hoped thatthe murderer would interpret “don’t know where” in a sense that would excludeyour knowing that your friend was in your house. (You may well have used a toneof voice and emphasis to encourage that misapprehension, e.g., awhy-are-you-bothering-me-? tone of voice. Try saying “I don’t know where sheis,” in different ways to see how you might be able to influence your imaginedaudience.) What you depend upon here to follow your obligation to tell thetruth and yet save your friend is the vagueness of “know where.”
Sandelillustrates his point further with Bill Clinton’s famous “I did not have sexualrelations with that woman.” (15:37- 18:03) The vagueness here is in “sexualrelations.” Clinton, in support of his truthfulness, presumably would havemaintained that oral sex did not constitute sexual relations, taking thatphrase to include only genital-genital intercourse. It seems obvious, however,that he used this phrase precisely because he knew that most people would takeit considerably more broadly.
Sandel apparently thinks that Kant would notcondemn Clinton’s ploy, or at least would not condemn it so sternly as he woulda lie. I think that Sandel is wrong in this because Clinton’s statement, aswell as much of what people try to pass off as deceptive truth telling is, infact, just lying.
Sandel,however, would be on reasonably firm ground in saying that Kant would agreewith him in characterizing the “don’t know where” and “sexual relations”statements as true. Unfortunately in this they would both be wrong, as I willsoon argue. If I am correct, then Kant’s absolutism about truth wouldimmediately undermine Sandel’s thesis about Kant’s attitude towards yourdeception of the murderer and Clinton’s deception of that very large televisionaudience.
It isnecessary here to make a point of historical clarification. What I am sayingwas a lie is “I did not have sexual relations with that woman, MissLewinsky.”I make no such claim about “Ihave never had sexual relations with Monica Lewinsky.” The first was in a televisedstatement from the Roosevelt Room of the White House on January, 26, 1998. Thesecond was a deposition response on February 17, 1998, in the Paula Jones case.The latter statement being under oath, raised an issue of perjury, vigorouslypursued by Ken Starr’s investigation and grand jury and by the Republican majorityof the Judiciary Committee of the House of Representatives.
As a witnessin the grand jury Clinton, speaking about the deposition, gave a defense thatwas unavailable for the televised statement. There was a loophole left byplaintiff’s lawyers in the definition of “sexual relations.”Under the deposition definition, to havesexual relations one must have contact with at least one body part of the other person that is listed inthe definition. The list does not include the mouth.Therefore under the definition, and so far as we know from the testimony ofLewinsky and Clinton, she had sexual relations with him (involving a listedbody part), but he did not have a sexual relations with her.
“Sexualrelations” is commutative, you say? Well, perhaps it is in common speech, butthat is one of the hazards of using stipulative definitions in a deposition.They take strict precedence over ordinary meanings.Clinton exploited this bit of weak lawyering.
Because his White House statement, the video of which Sandel showed his Harvard class, was made to the general public, however,and, in any event, came before the deposition definition was propounded,Clinton could only have defended it in terms of our common and everydaylanguage. That defense fails.
Because his White House statement, the video of which Sandel showed his Harvard class, was made to the general public, however,and, in any event, came before the deposition definition was propounded,Clinton could only have defended it in terms of our common and everydaylanguage. That defense fails.
After goingthrough that argument that no “sexual relations” and “don’t know where” are lies,I will shift fields to establish that there are some uncontroversially truedeceptive statements. I will then take a little deeper look at the question ofthe moral permissibility of deceptive truth, both from Kant’s point of view,and from ours as best we can have a view looking quickly.
Sandel helpshis cause rhetorically by talking about being “evasive” and “misleading truth” ratherthan about “deceiving” and “deceptive truth.” But intentionally to mislead isto deceive, and deception goes beyond evasion. I will use the more accurateterminology for the cases at issue.
- Few Deceptive Statements Exploiting Ambiguity or Vagueness Are Truthful
Consider acase in which everyone in the audience understands the content of what thespeaker said to be something that is, in fact, false, though false unbeknownstto the audience. The audience, then, is misinformed. They are deceived, as wellas misinformed, if the speaker, knowing its falsity, intended them to come tobelieve it.Usually this sort ofdeception is accomplished by lying. In the cases we are interested in, however,the speaker will deny lying, arguing that what he intended was a sense of whathe said on which it was true. The whole point of the maneuver is to avoidlying.
Clintoncould have said, “I never had any contact with that woman of the most remotelysexual nature.” That, however, would have been an unvarnished lie. He alsocould have told a benign truth, e.g. “I did not have genital-genital orgenital-anal sex with that woman.” The downside of such truthfulness, ofcourse, would have been the next questions that would have sprung up inmillions of minds. So Clinton chose, instead, to deceive, as best he might,without telling an unequivocal lie, at least by his own lights. He could latertry to defend his statement as true if worse came to worst. What was moreimportant to him than future damage control, however, was current deception.
I want toavoid, where possible, tedious niceties in distinguishing between truthfulnessas telling what is believed true (whether true or not) and truth telling assaying something that really is true (whether believed so or not). To that endI am going to assume that my speakers know the truth about what they aretalking. The speaker at the door was correct in believing his friend was inside,and Clinton knew what he had and had not done in the Oval Office.
When what thespeaker both intends and expects to communicate is false, and when she succeedsin communicating that falsehood, how could what she said be true?The key is supposed to be speaker intention.It is not what she intends her audience to come to understand, however, butinstead some internal elevation to the status of “her meaning” of somethingentertained but not communicated. Clinton's counsel at the impeachment hearings tried this exact line of argument. Clinton did not lie because of the meaning of 'sexual relations' 'in his own mind.' (lecture 17:22)
Clinton maywell have recited to himself mentally, “What I mean is that I did not havegenital-genital relations.”He could add“and I really, really mean that.”Butwhy should we take this little internal ceremony to have any relevance tofixing the meaning of what did not remain in the speaker’s head, but passed hislips and out to the television audience – an audience that he intended tounderstand something different from what he really, really privately meant?
The idea ofarriving at truth through private intending brings us to the very brink ofHumpty Dumptism: 'When I use aword,' Humpty Dumpty said in rather a scornful tone, 'it means just what Ichoose it to mean — neither more nor less.'A disciple of Humpty Dumpty can make “7 + 5 = 11” true so long asby “11” he intends “12”, but if he is teaching addition, his pupils may suffer someinconvenience.
Ourintuitions in the Clinton-type deceptive “truth” cases may be led a littleastray by influence from cases where the audience is misled, but there is nointent to deceive. A teen asked by an older brother whether he has “had sexualrelations” with his girlfriend, might naively think that “sexual relations”meant the same thing as “sexual intercourse” as defined by the rudimentary sexeducation module of his health course at school. (His teacher was shy aboutgoing into details.) So thinking, and therefore with a spotless conscience, theteen answers “No,” despite those study breaks he and his girlfriend take.
We would sayhere that the teen meant nothing false. The difference from the Clinton case,however, is that what the teen intended to communicate was true. He was unawareof the way his brother would understand what he said. I am not denying thattruthful statements often mislead because of vagueness or ambiguity. What Ideny is that there are (many) deceptivetruths of this sort. Where there is only one sense of a phrase of which the speakeris aware and under which he expects and intends his audience to understand whathe is saying, that sense has a strong enough relation to his public utteranceto use it in evaluating the truth or falsity of the statement.This is so even if we would be happy toexpand the description of the case from “What the teen said was true,” to “Whatthe teen meant to say was true, but what his brother understood wasfalse.”The key is that in intending tocommunicate it, the teen meant to saythe truth in a way that Clinton did not.
Ourintuitions may also be led astray in cases where the speaker, unlike our na誰ve teen,is aware that there are at least two senses of a key word or phrase, intends toconvey one, but can make a good argument that a different sense is somehowpreferred, canonical, or strict. She makes her mental reservation to the effectthat it is this latter sense that she “really means” while what she intends andexpects her audience to understand is another sense – one that will misleadthem.
Now thereare some instances in which canonical meanings really do govern whether astatement is true or false. The Clinton deposition case is one. It was a ruleof the deposition, blessed by the judge, that the first clause of the plaintiff’sdefinition of “sexual relations” was to be the meaning of that phrase for the deposition.The definition was shown to Clintonimmediately before he made his response. Where there is explicit stipulation, notrejected by the audience, it controls. To see whether any sort of canonicalmeanings determine truth or falsehood in other settings, however, requires alook at the specifics of the communication.
A neighbor istrying to organize a neighborhood watch, a project for which I have but tepidenthusiasm fearing it will compromise privacy or even degenerate intovigilantism. She asks me, “has your house ever been robbed?”As a former professor of criminal law, I knowthat what she really wants to know is whether I have been victimized by alarcenous burglary of my house.I tellher that my house “has never been robbed,” thinking to myself that no one hasstolen anything from my house using force or the threat of force. I picture tomyself a man with a gun standing outside my house and threatening to shoot itfull of holes if it doesn’t throw up its sashes and hand over its granitecounter top. On the other side of my mind is a clear memory of the time that athief came in through a window and stole some cash and credit cards from abillfold left downstairs.
I take a littlepride in reflecting that, if the neighborhood watch woman ever hears about thatincident and confronts me with my duplicity, I will be able to defend myself bygiving her a pious little lecture about the correct meaning of legalterms.Smug as I might be, I will,nonetheless, have lied. It was no deceptive truth, but a deceptive falsehood.Knowing she had no knowledge of the legal meaning of “robbery,” what Icommunicated to her was false. (I will shortly, however, consider a closelysimilar case that may well be a member of a small set of exceptions to theproposition that there are no deceptive truths of ambiguity or vagueness.)
Kant,himself, was, I think, tempted slightly off course by a “literal sense” case.
'Along withlying we may include: (a) aequivocatiomoralis, i.e. moral ambiguity, insofar as it is deliberately employed todeceive the other; for example, a Mennonite swore an oath that he had handedover the money he owed to his creditor, and in a literal sense he could swearthis, for he had hidden that very sum in a walking stick and asked hisadversary to hold it.'(Lectures onEthics)
I understandKant here to intend that this was not a lie, albeit an “along with,” i.e. asibling. I think he was in this too generous to the Mennonite, even though hewas obviously not being very generous to Mennonites as victims of 18thcentury German stereotyping.
Let us tryto elevate into a theory the intuition that I spoke truthfully about crime atmy house and that the Mennonite “could swear” as he did. The idea here is that astatement should be taken in the preferred sense (criminal law sense, literalsense) when evaluating its truth, even when there was no mutually acceptedstipulation in play, the preferred sense was neither the sense in which the speakerexpected the audience to understood the statement nor the way it was understood,and the speaker phrased and delivered his utterance to try to keep it frombeing so understood. If there werelanguage gods cognizant of and metaphysically enforcing best linguistic usage,my robbery statement and the Mennonite’s oath might be true on their languageOlympus, but it is hard to follow this theory to the conclusion that they weretrue when and where they were spoken.
If we were underthe spell of this theory, we might picture a spectrum ranging from Humpty-Dumptismat bottom to canonical meaning at the top.The deceiver can make no claims for truth atthe bottom, but his deceptive statement gets better and better marks as itstruth making sense gets closer and closer to the canonical top.
Something iscorrect about this spectrum picture. There are differences as we work our way up from Humpty Dumpty to canonical meaning. We may want to place moreblame on the audience for missing a sense of better authority or wideracceptance. We also feel more admiration, if grudging admiration, for thespeaker who can deceive by getting his audience to miss a more nearly common orauthoritative sense. These differences, however, do not affect the falsity ofwhat the speaker told his audience, a matter not decided in language heavenwhere the canonical prevails, but in the everyday world of what the speakerintended his audience to understand and what they did understand.
TheMennonite was depending upon anyone who heard or read his oath understanding “handedover the money”to mean something closeto the standard case in which the money is put, for all to see, into thecreditor’s hand, coin or bill to flesh, with the creditor having full andknowing control over it. His mentally reserved sense of “x was handed over,” hadto be broad enough to embrace “x was temporarily in the physical control of thereceiver without his having any way of knowing it.”
Kant,apparently, was convinced that this very broad interpretation of “handed over”is a “literal sense,” but that depends upon a word for word form of literalism,blind to the way meanings attach to phrases as well as to the effects of context.There is such a sense of “literal,” but it tends to be a pejorative sense, notone with good claims to canonicity, and, as argued above, even the trulycanonical only becomes the correct standard for evaluating the truth of astatement in special circumstances.
TheMennonite presumably believed that this was not a false swearing before God,who could look into his heart. We, however, might think such a God morallyobtuse or at least gullible. But let us pass that. If he thought he could notbe punished for perjury on this swearing if all the facts became known, I canonly say that I would far rather have the prosecution side than the defense. (Inever, in fact, prosecuted or defended a perjury action, although I think Idiscussed bringing perjury counts as a prosecutor, analyzed threatened perjurycharges against clients as a defense counsel, and spent a lot of energy tryingto prevent witnesses from straying towards perjury as a prosecutor, a criminaldefense lawyer, and a civil litigator.)
My centralthesis in all the above is that in evaluating whether someone is being truthfulor is lying we should look to the actual act of communication – what thespeaker intended the audience to understand and what the audience didunderstand.So focused we will judge fewif any deceptions relying upon ambiguity or vagueness to be truthful. Ofcourse, we are free to evaluate truth or truthfulness by focusing on whatever sensewe like of the words of a statement. Special purposes may promote to salience sensesof words other than those the speaker intended to communicate.For this reason, we may want to recognizedeceptive truths of ambiguity or vagueness in some exceptionalcircumstances.
- Possible Exceptions
One smallclass of exceptions or, at least, near exceptions, look to the future andinvolve vindication or correction. Suppose that my neighbor, rightlysuspicious, prepared an affidavit requiring me to state under penalties ofperjury that “my house has never been robbed during the period of myownership.”In the real world I woulddecline the request, but in a philosophical hypothetical in which I am a littlemore combative, I might sign it.I wouldbe unafraid of the penalties of perjury, knowing that in the unlikely event myaffidavit were shown to a prosecutor, no case would be brought because of thetechnical legal truth of my statement.
I actuallythink this case is best understood, not as an exception, a genuine deceptivetruth, but as a two audience, two statement case. I intend to deceive myneighbor, and as to her my affidavit is a lie. The affidavit as a legaldocument, however, has also a second audience, players in the justice system.The same signed words on paper that were a lie in the hands of the neighbor area non-deceptive truth in the hands of the prosecutor. Sworn statements are often prepared by lawyers,and decisions to prosecute for perjury are made by lawyers steeped in the criminallaw. The conventions of affidavit evaluation incorporate the legal argot. (Hereis the difference from the Mennonite’s walking stick case. “handed over” is notpart of the technical lexicon of the law, and the sense that made the oath trueis not one that would jump to the mind of lawyers or judges.)
Vindicationcan come more immediately and with the audience actually before the speaker. I tell my criminal law class that my house has never been robbed. Ithen recount the burglary of and theft from my house, and ask the class howwhat I have told them is consistent. Because this occurs early in the firstsemester, with no writing assignments yet made, some students will have read aheadand will have the answer, even if they were originally sucked in by my robberystatement.I could insist that this toois a two audience case, my na誰ve class of 10:20 AM and my enlightened class of10:24.I see no harm, however, inadmitting that this is a case in which I say something true and thereby succeedin deceiving, temporarily, by exploiting an ambiguity.
Here thecanonical status of the sense of “robbery” that made my statement true wasimportant to my pedagogical purpose, but, unlike the affidavit case, not thekey to the truth of my statement as I made it to the class. What made the true-makingsense relevant for analysis of truth or falsity was temporal. I was about to tellthe class the whole story, including explanation of the technical vocabulary ofrobbery, burglary, and larceny.Iintended them to hear my statement with their lay ears but also intended the technicalsense to become the dominant understanding of what they had just heard me say –as the definitions unfolded in their developing lawyerly brains.
Preferred, strict,or canonical meaning is not essential to this class of cases, as is illustratedby what has become a standard joke in situation comedies. It is pureHumpty-Dumptism. Here is an example from an episode of Scrubs:
Dr. Cox: Andthis... abomination is the reason we can't afford a new computer?
Dr. Kelso:Well, that, and a little medical boondoggle I have to go to in Cleveland. Andby 'medical boondoggle' I mean 'golf weekend.' And by'Cleveland' I mean 'Hawaii.' .... Anyway, I have to gocatch my bus to the airport. And by 'bus' I mean'helicopter.'
I am willingto call these deceptive truths of (Humpty-Dumpty) ambiguity, because the sensethat makes them true is shared with the audience while the words are stillhanging in the air.Were I stubbornly todefend my general proposition against even this exception, I would make the twoaudience move again.
Thestipulation case, as in the Clinton deposition, is a quasi-exception. What he thereexploited was the plaintiff’s definition and the fact that plaintiff’s lawyerswere not alert enough to notice the loophole that they had created. We couldcharacterize this as turning on the failure of plaintiff’s lawyers to recognizean ambiguity between what they thought their definition set out and what itreally did set out. It can also becharacterized as a seductive inference case, on which more next.
- Genuine Deceptive Truths
So withthese possible exceptions or near exceptions, I stand by my claim thatexploitation of ambiguity or vagueness to try to deceive while telling thetruth may succeed in deceiving, but will leave the speaker a liar.Yet I do think that there are absolutelyclear and uncontroversial cases of deceptive truth. They exploit, not ambiguityor vagueness, but seductive inference.
The visitingexpert birder: “I caught a fleeting glimpse of a large white bird. Did you seeit?” The deceiver responds, “The only bird I’ve seen this morning was acrow.”What the deceiver saw andrecognized was Hubert the neighborhood's resident albino crow. He maliciouslyexpects the birder to draw an inference from the very good generalization thatcrows are black to the conclusion that his respondent had not seen the mysterybird. The seductiveness of this inference is heightened by the particularcontext and the phrasing of the deceiver’s response. In normal conversation,this would be understood to be a colorfully amplified denial of having seen alarge white bird.That makes thedeception more effective, and, for those of us in the know, the deceptiveintent of the speaker all the clearer.
Opportunitiesto deceive through seductive inference are not quite as ubiquitous as thoseexploiting ambiguity or vagueness, but they are pretty common. “My uncle broughtin a muskellunge using his hand net.” This statement, standing alone, mightcause you to conclude that my uncle had more fishing prowess than he, in fact,possessed. He was a sometimes fisherman, to be sure, but not a muskie-levelfisherman. The fish of this anecdote was lying near death from an unfortunate encounterwith a propeller when my uncle spotted it and scooped it up by net from thelake surface.The crow and muskie casesare instances of what is often called deception by omission, and in most casesof omission what is omitted is precisely what would undermine the seductivenessof the inference for the audience.
Electioncampaigns sometimes cite legislative votes by their opponents that suggest, in isolation,the very opposite of the opponent’s policy positions.Complexity and gamesmanship in legislation:rival bills, friendly and unfriendly amendments, riders, and poison pills; allthese provide ample materials for sound bite deception of the electorate.
The SupremeCourt held in Bronston v. United States, 409U.S. 352, 352-53 (1973),that adeceptive truth of this conversationally seductive sort did not constituteperjury. (This is called the “literal truth defense,” though it would not go sofar as to protect the Mennonite against a perjury charge. Bronston’s swornstatement was unequivocally true. It was, like the white crow case, deceptivebecause of the question to which Bronston was supposed to be responding.)
- Moral Theory and Deceptive Truth – Kant
Havingestablished that there are some cases of unquestionably truthful deception, aswell as quite a few cases of lying that have wrongly been put in that category,I want now to turn to the moral evaluation of truthful deception. For these purposes I am going to assume thatmy argument in sections 1-3 is all wrong and that Kant and Sandel, are right about the truth of the “don’tknow” to the murderer,the “sexualrelations” to the in the televised statement, and the “handed over” oath. Thatis, I will assume that these, like the crow and muskie cases, are all deceptivetruths.
Sandel’schief point was that there is a significant moral difference between the “don’tknow where” to the murderer and Clinton’s sexual relations, on the one hand,and outright lying, on the other.Themotive of the latter is to deceive by lying and of the former is to deceive bytelling the truth. The idea is that doing the work of deception through truthtelling honors the moral law and follows the categorical imperative. (20:12-21:15).To fill in Sandel’s account a little, these statements satisfy the firstformulation of the categorical imperative with respect to their truth.
The secondformulation abjures us not to treat our audience solely as a means, andalthough these statements may use the hearer partially as a means, by deceivinghim, perhaps they do not treat him solely as a means in that they tell him thetruth.
Sandel couldbe making one of three different claims about Kant on deceptive truths. The mostradical is that deceptive truths for Kant are always morally permissible. Thesecond is that deceptive truths are morally prohibited, but are still morallysuperior to lying. The third is that deceptive truths are sometimes morally permitted.
When I firstwatched the video of Sandel’s lecture, I thought that he was making the radicalclaim. He welcomed his student’s “don’t know where” suggestion for the murderercase in a way that suggested that Sandel thought this was morally acceptable,and intuitively it does seem acceptable -- as a way of friend-saving. (If we are interpreting Kant, however,we have to be cautious in relying on such intuitions, remembering that it isflatly prohibited to lie to the murderer.)Without endorsing Clinton’s exoneration in so many words, Sandel alsoseemed reasonably comfortable in acting as Kant’s agent in letting thePresident off the hook.
On a second timethrough the lecture, however, I was struck by Sandel’s repeated use of such languageas “there is something morally at stake in the distinction” between lying anddeceptive truth. (17:55) There could bea morally significant distinction without all deceptive truth telling beingmorally permissible.The second twointerpretations of Sandel on Kant set out such distinctions.
I wasconcerned, however, that these lesser distinctions between lying and deceptivetruthfulness were uncongenial to the general spirit of Kant’s moral philosophy.At least with respect to the perfect duties, Kant’s view of the moral law seemsto be, well, categorical. An action is either in or it is out, morallypermissible, or morally prohibited, end of story. The absolute prohibitions ofall lying and all suicide bear this out. In the end, I suspect that the secondinterpretation, on which deceptive lying is morally impermissible but not sobad, is in irremediable conflict with Kant’s system.Of the third interpretation, however, thereis a good deal more that can be said, and some support from the Kant corpus.
To test themost radical interpretation of Sandel on Kant, we will want, first, to askwhether it would be a contradiction to the institution of communicatinginformation that all rational agents, as a law of nature, deceive theiraudience when that is in the agent’s interest and can be done without lying.Perhaps this law of nature would not collapse the practice of informationexchange with quite the conceptual immediacy that the universalization of lyingpromises collapses the practice of promising, but only because we are not quitesure how frequently it is possible to deceive with the truth. If, however, boththe “don’t know” to the murderer and Clinton’s “no sexual relations,” count astruths, as Sandel thinks, then we can speculate that whenever one is in a tightspot, it will be possible to conjure up some deceptive truth.If this is so, then deceptive truth telling,in full generality, is self-undermining in the same way that lying promisesare, and so fails the first formulation of the categorical imperative.
Mostinstances of deception are also specifically designed to manipulate theaudience in some way. By using the audience as a means, they fall afoul of thesecond formulation. That you did not use a yet worse means to manipulatehardly seems enough to get past the second formulation.
As for thethird formulation, and being “a legislating member in the universal kingdom ofends,” surely I am not permitted the option of deceiving my fellow legislatorsin every case in which I can do so without lying.
In short,the proposition that Kant would find that every instance of deceptive truthfollows the moral law is wildly implausible.
The second,and much weaker, interpretation of Sandel’s claim is that it is not morally asbad to deceive by telling a truth as by telling a falsehood. At least the truthtelling, taken in isolation, follows the moral law, and so there is an honoringof the moral law in one respect, even if your deception taken as whole violatesthat law. It is not crazy that a prohibited action that has a non-prohibitedcomponent is in some moral respect superior to an action every component ofwhich is prohibited.
Isn’t it better to murder your victim with a fast actingpoison that knocks the victim unconscious right off rather than with a poisonthat causes hours of suffering? Maybe it is even better to perpetrate a politerather than a verbally abusive armed robbery.
Isn’t it better to murder your victim with a fast actingpoison that knocks the victim unconscious right off rather than with a poisonthat causes hours of suffering? Maybe it is even better to perpetrate a politerather than a verbally abusive armed robbery.
If youraction is morally prohibited, however, I think that really is the end of thestory for Kant. Actions that violate the moral law do not get partial creditbecause they have components that would be morally permissible if they could beabstracted out of the whole action. There are no consolation prizes or runnersup for Kant. At least that is how it has always seemed to me when it came toviolations of the moral law. Recall that if 99% of your motivation wasobligation, but an essential 1% was self-interest, you have not acted with agood will. “Does an intending poisoner have an obligation to use a fast actingpoison?” is a question that does not arise for Kant. Perhaps it should, but itdoesn’t, or so my study of Kant, such as it is, leads me to think.
The thirdinterpretation of Sandel on Kant is the most interesting. It is that deceptivetruth telling is sometimes morally permissible and sometimes not.This would clearly satisfy Sandal’s “somethingmorally at stake” in the distinction between deceptive truth and outright lying.There is some evidence that Kant may well have held such a view about deceptivetruth, a view that can be supported by an attractive understanding of the waythe machinery of Kantian ethics should be applied to moral issues stated withparticularity.
Here is whatKant says in presenting the “handed over” oath case:
'A moralcasuistic would be very useful, and it would be an undertaking much to thesharpening of our judgment, if the limits were defined, as to how far we may beauthorized to conceal the truth without detriment to morality.'
(Or at leastthis is roughly what Kant said as what we have are only student transcriptionsof lectures. But we have reason to think the students were pretty accurate.) By“casuistic” Kant meant application of theory to particular cases.
Examinationof cases could never overthrow correct theory, which was established by reasonalone. (In this respect it is different from Rawls’s method of reflectiveequilibrium, on which theory can cause changes in our intuition about cases,but intuition about cases can also lead us to modify theory.) Kantian casuistrywould be about making the theory practical for everyday purposes – the finepoints of applying the categorical imperative to particular cases and classesof cases. This is what Kant must have meant by “judgment sharpening.”
It is clearenough that Kant would adjudge the Mennonite’s active, intentionally deceptive,concealment of the truth to be morally prohibited when theory was applied to it withany sharpness of judgment at all.Lookingto the first formulation of the categorical imperative, could we, withouta contradiction to the practice,universalize the maxim that, whenever one isfinancially embarrassed, one may swear to have handed over a loan repayment toa creditor even though the creditor did not really get possession of the money?Inasmuch as swearing in the hypothesizedcircumstance of such a universalized maxim would then be of no help indetermining whether a loan had or had not been paid, this maxim for debtor oathgiving would be self-defeating. On Kant’s second formulation of the categoricalimperative, it is pretty clear that the debtor was using those for whom theoath was intended as means only. Again, it comes up strictly morallyprohibited.
We canproject, and hope, that Kant would reach a different conclusion in other kindsof concealment of truth cases, for example slamming the door without answeringthe murderer or feigning Manx monoglotism.
So far as Iknow, Kant never much discussed what happens when obligations come intoconflict. By talking about casuistry as a judgment sharpening exercise,however, isn’t Kant telling us to look to the details of the particularcases?In determining “how far” we cango in concealing through deception, we need to examine an instance of deceptionin action and see whether, for example, it involves truth telling in a way thattakes the moral sting out of the deception.
Therepayment oath fails that test as would my house robbery answer to my neighbor.My house robbery statement to my law class, I think, would not. There would beno first formulation contradiction in a temporary deception for pedagogicalpurposes, and, if I was using my class momentarily perhaps as a means, I wastreating them in the larger picture as an end.
It seems tome, as it has to many, that Kant should have looked to the particulars tosharpen his judgment about cases where the obligation to tell the truth runsheadlong into other important obligations – the obligation to preserve aninnocent life from murder, for example. His universal prohibition of all lyingseems to conflict with his recognition of a role for casuistry.
This, ofcourse, is a substantial problem for this otherwise attractive interpretationof Kant. He was adamant and unambiguous about the impermissibility of lying. Iam not the first, however, to wonder if this wasn’t simply a mistake on Kant’spart. Shouldn’t he have been willing to sharpen his judgment about the correctway to apply the categorical imperative to lying by looking to more particularinstances of lying and the other morally relevant features they might have? Hisargument that it is flatly morally prohibited to lie to the murderer at thedoor has rarely gotten high marks for either clarity or soundness.
- Deceptive Truth and Moral Theory – a Little More Broadly
Stillkeeping Kant in mind, I want now to branch out a little in moral theoryoptions.
Consequentialists, who have always been sure that Kant was wrong inhis universal condemnation of lying, have their own straightforward test thatapplies to lying, deceptive truth telling, and everything else for that matter.Simply look to the consequences. If telling a deceptive truth appears to havebetter long run consequences than any other alternative you can reasonably comeup with, then tell the deceptive truth. (For the technical reasons Icharacterize consequentialism in this way, see my Philosophy Now paper, “The Impossibility of Maximizing GoodConsequences.”)
Consequentialists, who have always been sure that Kant was wrong inhis universal condemnation of lying, have their own straightforward test thatapplies to lying, deceptive truth telling, and everything else for that matter.Simply look to the consequences. If telling a deceptive truth appears to havebetter long run consequences than any other alternative you can reasonably comeup with, then tell the deceptive truth. (For the technical reasons Icharacterize consequentialism in this way, see my Philosophy Now paper, “The Impossibility of Maximizing GoodConsequences.”)
What consequentialismmay not be able completely to bring within its account are the various moralrelations that speakers have to audiences, and to persons affected by theaudience, more and richer in some cases than in others. These relations maywell militate against deception even when consequences are all factored out.
Thedifferences of those relations in different cases will give rise to obligationsnot to deceive various in strength and varying across subject matters. Consideran oil company executive who labors to deceive the audience of her publicspeech into thinking that there is no scientific consensus on climate change. Comparethat to a science teacher who seeks to perpetrate the same deception on hishigh school class. Some of what you compare, of course, will be differences inprobable consequences, but even if consequences are the same, violation of a closertrust relationship is morally worse.
Similarly,deceiving on a matter the audience considers important is worse than deceivingon something the audience regards as trifling. This is so even in those rarecases in which circumstances conspire so that the consequences of the deceptionon an important matter turn out to be insignificant.
It alsosomewhat plausible that there is a moral difference depending upon how far thebelief engendered by deception is from what the speaker believed to be true.This will, again, often lead to important differences in consequences, but evenif it doesn’t in a particular case, to deceive by a lot seems worse than todeceive by a little.
I think aKantian might be able to forge a pretty good argument that Kantian casuistry,when taken well beyond the few examples Kant gives us, will successfullyaccount for all the morally relevant relationships that will be involved in adifficult real world moral decision. Whether it can properly address allmorally relevant matters of consequence is much more doubtful. Even though notthe only factor, consequences are important in evaluating the morality ofactions. Yes, Kantian casuistry may beable to bring in some considerations of a consequential flavor in applicationof the moral law to particulars of the case.Yet, Kant clearly wanted to turn moral reasoning away from consequences. Certainly he gives clear warnings thatmuch in the way of consequence weighing is beneath moral contempt. Thequasi-consequences that can make their way into a Kantian casuistry are atleast not obviously sufficient to give consequences the full weight theydeserve.
So theevaluation of the moral status of intentional deception, although often easy inordinary life circumstances, can involve many factors of varying weight in thehard cases. I have doubts that either Kant or consequentialism can do justiceto the task.
- Deceptive Truth Versus Lying
Deeperexploration will show, I think, that only rarely will a deceptive truth takemuch moral precedence over a deceptive falsehood (contrary to our first andsecond interpretations of Sandel on Kant). “I didn’t see any large white birdthis morning” is only slightly worse than “the only bird I’ve seen this morningis a crow.” The breach of the relation of trust is the same, and theconsequences for the expert birder will most likely be the same. A differencemay arise if the albino crow possibility ever occurs to the birder and she thenthinks back to the specifics of the way the speaker answered the question andso is encouraged, with an irritated frown, to explore that possibility moreenergetically.
We also geta different case, with a difference that may well shift the impermissible topermissible, if there is a history of practical jokes between the birder andher respondent. We then have an entirely reconfigured relation of trust. For itsvalue as a joke, the truth of the deceptive statement is as important as is thecleverness of the deception.In additionto a difference in motivation, there is, again, an element of futurevindication in this sort of practical joke that can turn what would otherwisebe just mean spirited into a jolly gotcha. I will leave it as an exercise whether thissort of moral difference can be entirely accounted for either byconsequentialism or by Kantian casuistry.
One thing Iwant to deny outright is that there is, in the normal case, the slightest moraldifference between deceiving someone I really ought not deceive through a lieand through an intentionally and successfully deceptive truth. The evil of a deceptive truth here is the sameas that of a deceptive untruth. It is the wrongness of deception. That thedeceiver managed to be truthful in deceiving everyone may be a testament to hisor her cleverness, but, aside from such special cases as practical jokes, truthis irrelevant if it does not lessen the probability of deception, itspermanence, the confidence of the audience in what they are deceived intobelieving, or the consequences of the deception.
To return toan earlier theme, you may have the following question. Even if it is right thatthe core evil or the greater part of the evil in lying deception is thedeception, still isn’t a truthful deception at least a little better than alying deception?Truth is better thanfalsity, and so honoring truth, even in the midst of a transaction morallyreprehensible for other reasons, has to be at least a little bit good or makethe whole slightly less bad.
I can feel afaint tug of intuition in this direction, but I think it is due to the(fortunately distant) siren call of an insupportable purity ethic. Speaking aknown untruth is a stain on my moral soul quite independent of my relation tomy audience and consequences? I don’tthink so. The moral pivot here is the deceived audience. The value of truthover falsehood disappears with the audience connection. If you are alone,please say, out loud, “5 + 7 = 12” and then “5 + 7 = 11.”Was there any moral difference?
- Conclusion
There arefew, if any, cases of deceptive truthfulness exploiting ambiguity orvagueness.Those there may be evaluatetruth by looking, not to the immediate communication, but to some othercontext, often future disambiguation, precisification, correction orvindication. To redound to the truthfulness of the speaker, the alternativecontext must be made salient by some feature of the actual context, e.g.immediate transition from one to the other (“by “Cleveland I mean Hawaii”') or bysome rule or convention known to the speaker (the legal lexicon for anaffidavit.)
The Kantianabsolute prohibition of all lying would, therefore, make Sandel wrong if hewere claiming that Kant would find morally permissible “don’t know where” tothe murderer at the door and the televised “I did not have sexual relationswith that woman.”
There are,however, uncontroversial cases of deceptive truth turning on seductiveinference. So it is worthwhile seeing what Kant might and we should say aboutthe moral permissibility of deceiving while telling the truth.Kantian casuistry has the potential, I think, to rulesome instances of deceptive truth permissible and others prohibited. This would partially vindicate the theoretical point that Sandel intended to make in his lecture.Kantian casuistry would apply the categorical imperative after using judgmentto tease out the morally relevant features of the particular case. Thisprocedure might be extended so far as to reach the conclusion that some liesare morally permissible, Kant to the contrary notwithstanding.
When we areevaluating the moral permissibility of a deceptive truth, we should look toconsequences (in a way that even an enriched Kantian casuistry probably cannot)and to the morally relevant relations between the speaker and the audience (ina way that even sophisticated consequentialism probably cannot). Only in few and special circumstances will atruth used to deceive and completely successful in its deception be morallysuperior to a falsehood used to the same purpose and effect.
- Addendum on the Impeachment
Clinton’s “sexual relations” statement in the Paula Jones deposition was covered bycharge (2) of Article II of the Articles of Impeachment brought against Clintonby the House Judiciary Committee, all Democrats and one Republican voting nay.It was also indirectly implicated in Article I, perjury before the grand jury, charge(2). Clinton was interrogated in the grand jury about his deposition responses,among many other things. Article II came out of the Committee with a straightparty line vote.
Clintonclearly lied in his deposition in answering the question whether he andLewinsky had ever been alone in the Oval Office. His response was “I don’tremember” followed by some true, if not so responsive, remarks. In light ofwhat went on when they were alone, it is unbelievable that he didn’tremember.I concede that in takingdepositions myself I have heard hundreds of “I don’t remember”s that I was quite surewere false. Some lawyers believe that this particular lie should begiven a free pass, and very frequently judges seem to agree. The practice, however, is a clearcorruption of law. In any event, we do have an intentional falsehood in thedeposition. Whether it is material to the Paula Jones case, and thusconstitutes perjury, is a separate question, although I tend to think thatwithin the materiality standard of discovery, it was material and so perjurious.
Clinton wasnot impeached on Article II, the Paula Jones deposition perjury charges, by avote in the House of 229-205. He was impeached on Article I, the grand jurycharges by a vote of 228-206. (He was also impeached on Article III, obstructionof justice in the Jones case and grand jury investigation, mostly witnesstampering. He was not impeached on Article IV, abuse of power in dealings withthe House on impeachment related matters.)
He was notconvicted in the Senate on either of the two remaining articles.Article I, more closely connected with thealleged perjuries, was rejected 55-45. The obstruction of justice charge failed50-50, 67 votes being required for conviction.
Some of thesenators who voted against conviction stated their belief that Clinton hadcommitted perjury. A perjury is unquestionably a crime. Is it a “highcrime”?“High crimes and misdemeanors” was a term oflegal art, more particularly of legal art of the English constitutional lawtradition. (For more on constitutional interpretation in general, and terms ofart in particular, see my post “A Textualist Approach to Legal Interpretation,6/17/2014.) It is reasonably clear that the term of art was restricted in itsapplication to misdeeds in official capacity.Accepting a bribe by an official is a high crime and misdemeanor; the official’s shootingher husband is not.Perjury is arguablyin a middle category. Perjury can be committed by anyone who is put under oath.In that respect it is like spousicide.However, it is itself a matter of an obligation intimately tied to themechanisms of the administration of state justice. Officials, at leastofficials with any relation to the justice system, arguably have obligations touphold the integrity of oath taking that go beyond those of ordinary citizens.
The entireconstitutional phrase is “Treason, Bribery, and other high Crimes and Misdemeanors.” Treason can be committed by non-officials. Bribe giving can aswell, and I suspect that “bribery” included giving as well as taking in theeighteenth century. However, I also suspect that bribery as an impeachableoffense would have been read here as “bribe taking” and that “treason” was readwith understanding of the particular seriousness of official treason. Thatthese were given as the exemplar cases of “high crimes and misdemeanors”suggests that the class is a matter of serious offenses against the state ofthe sort that officials are either uniquely well placed to commit or at least verywell placed.
That theoffense must be one against the state is evidenced by the fact that theoriginal text was “Treason, Bribery, and other high Crimes and Misdemeanorsagainst the United States.”“against theUnited States” was taken out by the Committee on Style, the charge of which wasto improve style without changing content.I cite this, not to argue that it was the intent of the drafters tolimit impeachment to offenses against the United States. I don’t think drafter intent,as such, counts for anything. (If this issue is of interest, you really should see the 6/17 post.) Thedelegates, and in particular the members of the Committee on Style, were,however, fluent speakers of late 18th century American English andgenerally familiar with legal terms of art. That they thought “against theUnited States” could be removed as a matter of style is pretty good evidence ofthe meaning, at that time, of “high Crimes and Misdemeanors.”
So, althoughI would want to do more research before voting, I think that I would have votedagainst impeachment in the House and conviction in the Senate for Clinton’sperjury. “I never had sexual relations” in the Paula Jones deposition was notfalse (so far as the evidence shows) because of the defective definitiongoverning the deposition. It was deceptive in the same way as his nearlyidentical televised lie, but the deposition statement was notperjury.“I don’t remember,” was perjury. But thatcrime did not rise to the level of a serious office-related crime against theUnited States.For posts on more nearly current impeachment issues, see:
Was Trump’s “Russia, if you are listening, . . . “ Criminal?Impeachable?
Was Trump’s criticism of Sessions for permitting indictmentsof Republican House members a high crime or misdemeanor?
Should President Pence be Impeached with Vice PresidentTrump in the Wings?
First published Wed Jun 4, 2008; substantive revision Sun Nov 4, 2018
Kant famously attempted to “answer” what he took to beHume’s skeptical view of causality, most explicitly in theProlegomena to Any Future Metaphysics (1783); and, becausecausality, for Kant, is a central example of a category or pureconcept of the understanding, his relationship to Hume on this topicis central to his philosophy as a whole. Moreover, becauseHume’s famous discussion of causality and induction is equallycentral to his philosophy, understanding the relationship between thetwo philosophers on this issue is crucial for a proper understandingof modern philosophy more generally. Yet ever since Kant offered hisresponse to Hume the topic has been subject to intense controversy.There is no consensus, of course, over whether Kant’s responsesucceeds, but there is no more consensus about what this response issupposed to be. There has been sharp disagreement concerningKant’s conception of causality, as well as Hume’s, and,accordingly, there has also been controversy over whether the twoconceptions really significantly differ. There has even beendisagreement concerning whether Hume’s conception of causalityand induction is skeptical at all. We shall not discuss thesecontroversies in detail; rather, we shall concentrate on presentingone particular perspective on this very complicated set of issues. Weshall clearly indicate, however, where especially controversial pointsof interpretation arise and briefly describe some of the mainalternatives. (Most of this discussion will be confined to footnotes,where we shall also present further, more specialized details.)
- Bibliography
- Primary Sources
1. Kant’s “Answer to Hume”
In the Preface to the Prolegomena Kant considers the supposedscience of metaphysics. He states that “no event has occurredthat could have been more decisive for the fate of this science thanthe attack made upon it by David Hume” and goes on to say that“Hume proceeded primarily from a single but important concept ofmetaphysics, namely, that of the connection of cause andeffect” (4, 257; 7; see the Bibliography for our method ofcitation). Over the next few pages Kant defends the importance ofHume’s “attack” on metaphysics against common-senseopponents such as Thomas Reid, James Oswald, James Beattie, and JosephPriestley (all of whom, according to Kant, missed the point ofHume’s problem), and Kant then famously writes (4, 260; 10):
I freely admit that it was the remembrance of David Hume which, manyyears ago, first interrupted my dogmatic slumber and gave myinvestigations in the field of speculative philosophy a completelydifferent direction.
Thus, it was Hume’s “attack” on metaphysics (and, inparticular, on the concept of cause and effect) which first provokedKant himself to undertake a fundamental reconsideration of this(supposed) science.
Later, in §§ 27–30 of the Prolegomena, Kantreturns to Hume’s problem and presents his own solution. Kantbegins, in § 27, by stating that “here is now the place toremove the Humean doubt from the ground up” (4, 310; 63); and hecontinues, in § 29, by proposing
to make a trial with Hume’s problematic concept (hiscrux metaphysicorum), namely the concept of cause.(4, 312; 65)
Kant concludes, in § 30, by stating that we are now in possessionof “a complete solution of the Humean problem” (4, 313;66)—which, Kant adds,
rescues the a priori origin of the pure concepts of the understandingand the validity of the general laws of nature as laws of theunderstanding, in such a way that their use is limited only toexperience, because their possibility has its ground merely in therelation of the understanding to experience, however, not in such away that they are derived from experience, but that experience isderived from them, a completely reversed kind of connection whichnever occurred to Hume. (ibid.)
Thus, Kant’s “complete solution of the Humeanproblem” directly involves him with his whole revolutionarytheory of the constitution of experience by the a priori concepts andprinciples of the understanding—and with his revolutionaryconception of synthetic a priori judgments.
Indeed, when Kant first introduces Hume’s problem in the Prefaceto the Prolegomena he already indicates that the problem isactually much more general, extending to all of the categories of theunderstanding (4, 260; 10):
I thus first tried whether Hume’s objection might not berepresented generally, and I soon found that the concept of theconnection of cause and effect is far from being the only one by whichthe understanding thinks connections of things a priori; rather,metaphysics consists wholly and completely of them. I sought to securetheir number, and since this succeeded as desired, namely, from asingle principle, I then proceeded to the deduction of these concepts,on the basis of which I was now assured that they are not derived fromexperience, as Hume had feared, but have sprung from the pureunderstanding.
Moreover, Kant soon explains, in § 5, how this more generalproblem (common to all the categories and principles of theunderstanding) is to be formulated: “How is cognition from purereason possible?” (4, 275; 27), or, more specifically,“How are synthetic a priori propositions possible?” (4,276; 28).
In the Introduction to the second (B) edition of the Critique ofPure Reason (1787), Kant follows the Prolegomena informulating what he here calls “the general problem of purereason” (B19): “How are synthetic a priori judgmentspossible?” And, as in the Prolegomena, Kant insiststhat the possibility of metaphysics as a science entirely depends onthis problem (ibid.):
That metaphysics until now has remained in such a wavering state ofuncertainty and contradictions is to be ascribed solely to the factthat this problem, and perhaps even the distinction betweenanalytic and synthetic judgments, was not thought ofearlier. Metaphysics stands or falls with the solution of thisproblem, or on a satisfactory proof that the possibility it requiresto be explained does not in fact obtain.
Kant then immediately refers to “David Hume, who, among allphilosophers, came closest to this problem”; and he suggests,once again, that Hume failed to perceive the solution because he didnot conceive the problem in its
[full] generality, but rather stopped with the synthetic propositionof the connection of the effect with the cause (principiumcausalitatis). (ibid.)
It is only in the second edition of the Critique that Kantgives such a prominent place to Hume and his “objection”to causality, serving to introduce what Kant now calls “thegeneral problem of pure reason”. By contrast, the name of Humedoes not appear in either the Introduction or the TranscendentalAnalytic in the first (A) edition (1781): it appears only in theTranscendental Doctrine of Method at the very end of the book, in adiscussion of “skepticism” versus “dogmatism”in metaphysics (where Hume’s skepticism about causation, inparticular, is finally explicitly discussed). This is not to say, ofcourse, that implicit references to Hume are not found earlier in thetext of the first edition. Thus, for example, in a preliminary sectionto the Transcendental Deduction Kant illustrates the need for such adeduction with the concept of cause, and in both editions remarks(A91/B124):
Appearances certainly provide cases from which a rule is possible inaccordance with which something usually happens, but never that thesuccession is necessary; therefore, a dignity pertains to thesynthesis of cause and effect that cannot be empirically expressed atall, namely, that the effect does not merely follow upon the cause butis posited through it and follows from it.
But it is only in the second edition that Kant then goes on to mention“David Hume” explicitly, as one who attempted to derivethe pure concepts of the understanding from experience (B127):
namely, from a subjective necessity arising from frequent associationin experience—i.e., from custom—which issubsequently falsely taken for objective.
This striking difference between the two editions clearly reflects theimportance of the intervening appearance of theProlegomena.
Given the crucial importance of the Prolegomena in thisrespect, it is natural to return to Kant’s famous remarks in thePreface to that work, where, as we have seen, Kant says that
it was the remembrance of David Hume which, many years ago, firstinterrupted my dogmatic slumber and gave my investigations in thefield of speculative philosophy a completely different direction.
It is natural to wonder, in particular, about the precise years towhich Kant is referring and the specific events in his intellectualdevelopment he has in mind. Here, however, we now enter controversialterrain, where there are basically two competingalternatives—both of which reflect the circumstance that Kantcould read Hume only in German translation.
Kant might be referring, on the one hand, to the late 1750s to mid1760s. A translation of Hume’s Enquiry Concerning HumanUnderstanding (originally published in 1748) appeared in 1755 andwas widely read in Germany. Kant had almost certainly read thistranslation by the mid 1760s, by which time he himself expresseddoubts about whether causal connections could be known by reason aloneand even suggested that they were knowable only by experience. Or, onthe other hand, Kant might be referring to the mid 1770s. After theInaugural Dissertation appeared in 1770, Kant publishednothing more until the first edition of the Critique in 1781.Meanwhile, a German translation of Beattie’s Essay on theNature and Immutability of Truth (originally published in 1770)appeared in 1772, where, in particular, Beattie quoted extensivelyfrom Book 1 of Hume’s Treatise of Human Nature(originally published in 1739). Thus, in the famous “dogmaticslumber” passage, Kant might be referring either to the mid1760s, when he then had a “remembrance” of reading thetranslation of Hume’s Enquiry, or to the mid 1770s,when he then had a “remembrance” of reading translationsfrom the Treatise.[1]
We prefer the first alternative. From this point of view, the decisiveevent to which Kant is referring is his reading of Hume’sEnquiry (in translation) during the late 1750s to mid 1760s,and this event, we believe, is clearly reflected in two importantwritings of the mid 1760s: the Attempt to Introduce the Concept ofNegative Magnitudes into Philosophy (1763) and Dreams of aSpirit-Seer Explained by Dreams of Metaphysics (1766).
In the first (1763) essay Kant introduces the distinction between“logical grounds” and “real grounds”, both ofwhich indicate a relationship between a “ground” (cause orreason) and a “consequent” (following from this ground).Kant explains his problem as follows (2, 202; 239):
I understand very well how a consequent may be posited through aground in accordance with the rule of identity, because it is found tobe contained in [the ground] by the analysis of concepts. …[A]nd I can clearly comprehend this connection of the ground with theconsequent, because the consequent is actually identical with part ofthe concept of the ground …. However, how something may flowfrom another, but not in accordance with the rule of identity, issomething that I would very much like to have made clear to me. I callthe first kind of ground a logical ground, because its relation to theconsequent can be logically comprehended in accordance with the ruleof identity, but I call the second kind of ground a real ground,because this relation indeed belongs to my true concepts, but themanner of this [relation] can in no way be estimated. With respect tosuch a real ground and its relation to the consequent, I pose myquestion in this simple form: how can I understand the circumstancethat, because something is, something else is to be? Alogical consequent is only posited because it is identical with theground.
The fundamental problem with the relationship between a real groundand its consequent, therefore, is that the consequent is notidentical with either the ground or a part of this concept—i.e.,it is not “contained in [the ground] by the analysis ofconcepts”.
Thus, using his well-known later terminology (from theCritique and the Prolegomena), Kant is here sayingthat, in the case of a real ground, the relationship between theconcept of the consequent (e.g., an effect) and the concept of theground (e.g., a cause) is not one of containment, and the judgmentthat the former follows from the latter is therefore notanalytic. Moreover, although Kant does not explicitly referto Hume in the essay on Negative Magnitudes, he proceeds toillustrate his problem with an example (among others) of the causalconnection in the communication of motion by impact (2, 202; 240):
A body A is in motion, another B is at rest in thestraight line [of this motion]. The motion of A is something,that of B is something else, and, nevertheless, the latter isposited through the former.
Hume famously uses this example (among others) in the Enquiryto illustrate his thesis that cause and effect are entirely distinctevents, where the idea of the latter is in no way contained in theidea of the former (EHU 4.9; SBN 29):
The mind can never possibly find the effect in the supposed cause, bythe most accurate scrutiny and examination. For the effect is totallydifferent from the cause, and consequently can never be discovered init. Motion in the second billiard-ball is a quite distinct event frommotion in the first; nor is there anything in the one to suggest thesmallest hint of the other.
A few lines later Hume describes this example as follows (EHU 4.10;SBN 29):
When I see, for instance, a billiard-ball moving in a straight linetowards another; even suppose motion in the second ball should byaccident be suggested to me, as the result of their contact orimpulse; may I not conceive, that a hundred different events might aswell follow from the cause? … All these suppositions areconsistent and conceivable.
In Kant’s second essay from this period, Dreams of aSpirit-Seer (1766), he goes further: he suggests a Humeansolution to the problem he had posed, but did not solve, in the essayon Negative Magnitudes. Kant suggests, more specifically,that the relation between a real ground and its consequent can only begiven by experience (2, 370; 356):
It is impossible ever to comprehend through reason how something couldbe a cause or have a force, rather these relations must be takensolely from experience. For the rule of our reason extends only tocomparison in accordance with identity andcontradiction. But, in so far as something is a cause, then,through something, something else is posited, andthere is thus no connection in virtue of agreement to befound—just as no contradiction will ever arise if I wish to viewthe former not as a cause, because there is no contradiction [in thesupposition that] if something is posited, something else iscancelled. Therefore, if they are not derived from experience, thefundamental concepts of things as causes, of forces and activities,are completely arbitrary and can neither be proved nor refuted.
This passage seems clearly to recall the main ideas in section 4, part1 of Hume’s Enquiry. After distinguishing between“relations of ideas” and “matters of fact”,and asserting that the former “are discoverable by the mereoperation of thought” (EHU 4.1; SBN 25), Hume continues (EHU4.2; SBN 25):
Matters of fact, which are the second objects of human reason, are notascertained in the same manner; nor is our evidence of their truth,however great, of a like nature with the foregoing. The contrary ofevery matter of fact is still possible; because it can never imply acontradiction ….
Hume then explains that: “all reasonings concerning matters offact seem to be founded on the relation of Cause andEffect” (EHU 4.4; SBN 26) and adds (EHU 4.6; SBN 27):
I shall venture to affirm, as a general proposition, which admits ofno exception, that the knowledge of this relation is not, in anyinstance, attained by reasonings a priori; but arisesentirely from experience, when we find that any particular objects areconstantly conjoined with each other.
Finally (EHU 4.10; SBN 29):
And as the first imagination or invention of a particular effect, inall natural operations, is arbitrary, where we consult not experience;so must we also esteem the supposed tye or connexion between the causeand effect, which binds them together, and renders it impossible thatany other effect could result from the operation of that cause.
Thus, although Kant does not explicitly mention Hume in Dreams ofa Spirit-Seer, the parallels with Hume’s Enquiryare striking indeed.[2]
Kant does not endorse a Humean solution to the problem of the relationbetween cause and effect in the critical period (beginning with thefirst edition of the Critique in 1781): he does not (as hehad in Dreams of a Spirit-Seer) claim that this relation isderived from experience. Instead (as we have seen) Kant takesHume’s problem of causality to be centrally implicated in theradically new problem of synthetic a priori judgments. Yet the latterproblem, in turn, clearly has its origin in Kant’s earlierdiscussion (in the essay on Negative Magnitudes andDreams of a Spirit-Seer) of the apparently mysteriousconnection between a real ground (or cause) and its consequent (oreffect). Just as Kant had earlier emphasized (in these pre-criticalworks) that the consequent of a real ground is not contained in it,and thus does not result by “the analysis of concepts”,Kant now (in the critical period) maintains that the concept of theeffect cannot be contained in the concept of the cause and,accordingly, that a judgment relating the two cannot be analytic. Sucha judgment, in Kant’s critical terminology, must now besynthetic—it is a judgment in which “the connection of thepredicate with the subject … is thought withoutidentity”, where
a predicate is added to the concept of the subject which is by nomeans thought in it, and which could not have been extracted from itby any analysis. (A7/B10–11)
The crucial point about a synthetic a priori judgment,however, is that, although it is certainly not (as a priori) derivedfrom experience, it nonetheless extends our knowledge beyond merelyanalytic judgments.
It therefore becomes clear why, in the Introduction to the secondedition of the Critique, Kant says of the crucial problem ofsynthetic a priori judgments that
this problem, and perhaps even the distinction betweenanalytic and synthetic judgments, was not thought ofearlier,
and then explicitly names “David Hume, who, among allphilosophers, came closest to this problem” (B19). It alsobecomes clear why, in the Preface to the Prolegomena, Kantexplains Hume’s problem as follows (4, 257; 7):
Hume proceeded primarily from a single but important concept ofmetaphysics, namely, that of the connection of cause andeffect … , and he challenged reason, which here pretendsto have generated this concept in her womb, to give him an account ofby what right she thinks that something could be so constituted that,if it is posited, something else must necessarily also be positedthereby; for this is what the concept of cause says. He provedindisputably that it is completely impossible for reason to think sucha connection a priori and from concepts [alone] (for this [connection]contains necessity); but it can in no way be comprehended how, becausesomething is, something else must necessarily also be, and how,therefore, the concept of such a connection could be introduced apriori.
Thus here, in the Prolegomena, Kant describes what he callsHume’s “challenge” to reason concerning“the connection of cause and effect” in preciselythe same terms that he had himself earlier used, in the 1763 essay onNegative Magnitudes and the 1766 Dreams of aSpirit-Seer, to pose a fundamental problem about the relation ofa real ground (as opposed to a logical ground) to its consequent.
What is most important, however, is the official solution toHume’s problem that Kant presents in § 29 of theProlegomena. This solution depends on the distinction between“judgments of perception” and “judgments ofexperience” which Kant has extensively discussed in thepreceding sections. In § 18 Kant introduces the distinction asfollows (4, 298; 51):
Empirical judgments, in so far as they have objectivevalidity, are judgments of experience; they,however, in so far as they are only subjectively valid, Icall mere judgments of perception. … All ofour judgments are at first mere judgments of perception: they arevalid merely for us, i.e., for our subject, and only afterwards do wegive them a new relation, namely to an object, and we intend that [thejudgment] is supposed to be also valid for us at all times andprecisely so for everyone else; for, if a judgment agrees with anobject, then all judgments about the same object must also agree amongone another, and thus the objective validity of the judgment ofexperience signifies nothing else but its necessary universalvalidity.
Then, in § 22, Kant emphasizes that the pure concepts of theunderstanding or categories function precisely to convert mere(subjective) perceptions into objective experience by effecting a“necessary unification” of them (4, 305; 58):
Therefore, the pure concepts of the understanding are those conceptsunder which all perceptions must first be subsumed before they canserve as judgments of experience, in which the synthetic unity ofperceptions is represented as necessary and universally valid.[3]
Here is how Kant formulates his solution in § 29 (4, 312;65):
In order to make a trial with Hume’s problematicconcept (his crux metaphysicorum), namely theconcept of cause, first, there is given to me a priori, by means oflogic, the form of a conditional judgment in general, namely, to use agiven cognition as ground and the other as consequent. It is possible,however, that a rule of relation is found in perception which saysthat a given appearance is constantly followed by another (but notconversely); and this is a case for me to employ the hypotheticaljudgment and, e.g., to say: if a body is illuminated sufficiently longby the sun, then it becomes warm. Here, there is certainly nonecessity of connection as yet, and thus [not] the concept of cause.However, I continue and say that, if the above proposition, which ismerely a subjective connection of perceptions, is to be a judgment ofexperience, then it must be viewed as necessary and universally valid.But such a proposition would be: the sun is through its light thecause of heat. The above empirical rule is now viewed as alaw—and, in fact, not as valid merely of appearances, but[valid] of them on behalf of a possible experience, which requirescompletely and thus necessarily valid rules.
All the elements from Kant’s earlier discussion of causality inthe essays on Negative Magnitudes and Dreams of aSpirit-Seer seem to be present here. Kant begins with the purelylogical relation between ground and consequent. Since, in the case ofthe concept of cause, we are dealing with what Kant had earlier calleda real ground, Kant holds that we need a synthetic ratherthan merely analytic connection between the two. The most obviousthought, which Hume had defended in the Enquiry (and,apparently following Hume, Kant himself had defended in Dreams ofa Spirit-Seer) is that “experience” (in the Humeansense) is the basis for this connection in so far as one perception isfound to be “constantly conjoined” with another. Now,however, in the critical period, Kant introduces a revolutionary newconcept of “experience” which is explicitly opposed tomere constant conjunctions among perceptions in being “necessaryand universally valid”—in particular, “experience ispossible only by means of the representation of a necessary connectionof perceptions” (B218).
In Kant’s example from § 29 of the Prolegomena,then, we begin from a mere subjective “empirical rule”:that the perception of an illuminated stone is constantly followed bythe perception of heat; and we then convert this “empiricalrule” into an objective law according to which the very samerelationship is now viewed as “necessary and universallyvalid”. This transformation is effected by the addition of the apriori concept of causality: “the sun is through its light thecause of heat”. It is in precisely this way, more generally,that the categories or pure concepts of the understanding relate toexperience:
not in such a way that they are derived from experience, but thatexperience is derived from them, a completely reversed kind ofconnection which never occurred to Hume. (§ 30: 4, 313; 66)
We shall devote the rest of this article to clarifying Kant’ssolution and its relationship with Hume’s conception ofcausation. For now, we simply note an important difficulty Kanthimself raises in the Prolegomena. Whereas the concept ofcausality is, for Kant, clearly a priori, he does not think thatparticular causal laws relating specific causes with specific effectsare all synthetic a priori—and, if they are not a priori, howcan they be necessary? Indeed, Kant illustrates this difficulty, in afootnote to § 22, with his own example of the sun warming a stone(4, 305; 58):
But how does this proposition, that judgments of experience aresupposed to contain necessity in the synthesis of perceptions, agreewith my proposition, urged many times above, that experience, as aposteriori cognition, can yield only contingent judgments? If I saythat experience teaches me something, I always mean only theperception that lies within in it, e.g., that heat always follows theillumination of the stone by the sun. That this heating resultsnecessarily from the illumination by the sun is in fact contained inthe judgment of experience (in virtue of the concept of cause); but Ido not learn this from experience, rather, conversely, experience isfirst generated through this addition of the concept of theunderstanding (of cause) to the perception.
In other words, experience in the Humean sense teaches me that heatalways (i.e., constantly) follows the illumination of the stone by thesun; experience in the Kantian sense then adds that:
the succession is necessary; … the effect does notmerely follow upon the cause but is posited through it andfollows from it. (A91/B124)
But what exactly does this mean?
2. Induction, Necessary Connection, and Laws of Nature
Kant formulates a crucial distinction between “strict” and“comparative” universality in § II of theIntroduction to the second edition of the Critique(B3–4):
Experience never gives its judgments true or strict, but merelyassumed or comparative universality (through induction), sothat, properly speaking, it must be formulated: so far as we haveobserved until now, no exception has been found to this or that rule.If, therefore, a judgment is thought with strict universality, i.e.,so that no exception at all is allowed to be possible, then it is notderived from experience, but is valid absolutely a priori. Empiricaluniversality is thus only an arbitrary augmentation of validity fromthat which is valid in most cases to that which is valid inall—as, e.g., in the proposition: all bodies are heavy. Bycontrast, where strict universality essentially belongs to a judgment,this [universality] indicates a special source of cognition for [thejudgment], namely a faculty of a priori cognition. Necessity andstrict universality are thus secure criteria of an a priori cognition,and also inseparably belong together.
Kant then explicitly links this distinction to Hume’s discussionof causality in the following paragraph (B5):
The very concept of cause so obviously contains the concept of anecessity of the connection with an effect and a strict universalityof the rule, that the concept [of cause] would be entirely lost if onepretended to derive it, as Hume did, from a frequent association ofthat which happens with that which precedes, and [from] a therebyarising custom (thus a merely subjective necessity) of connecting representations.[4]
Moreover, in the second edition (as we have seen) Kant also goes on toname Hume explicitly, as one who attempted to derive the concept ofcausality
from a subjective necessity arising from frequent association inexperience—i.e., from custom—which issubsequently falsely taken for objective. (B127)
It appears, therefore, that Kant’s discussion, in § 29 ofthe Prolegomena, of how, by the addition of the concept ofcause, we convert a mere subjective “empirical rule” intoan objective law (which is “necessary and universallyvalid”), is not only indebted to Hume for the insight that theconnection between cause and effect is synthetic rather than analytic,it is also indebted to Hume’s discussions of the problem ofinduction (in section 4, part 2 of the Enquiry) and of theidea of necessary connection (in section 7). Kant agrees with Humethat the idea of necessary connection is in fact an essentialingredient in our idea of the relation between cause and effect; Kantagrees, in addition, that, if all we had to go on were a purelyinductive inference from observed constant conjunctions, the inferencefrom comparative to strict universality would not be legitimate, andthe presumed necessary connection arising in this way (i.e., fromcustom) would be merely subjective.
Section 4 of the Enquiry is entitled “Sceptical DoubtsConcerning the Operations of the Understanding”. In part 1 ofthis section (as we have already seen) Hume maintains that the idea ofthe effect is never contained in the idea of the cause (inKant’s terminology, the relation is not analytic), and thus,according to Hume, it is never knowable a priori. We therefore needexperience in the Humean sense in order to make any causalclaims—that is, the observation of an event of one typeA constantly followed by an event of another type B.Otherwise (as we have also seen) any event could follow any other (EHU4.10; SBN 29):
And as the first imagination or invention of a particular effect, inall natural operations, is arbitrary, where we consult not experience;so must we also esteem the supposed tye or connexion between the causeand effect, which binds them together, and renders it impossible thatany other effect could result from the operation of that cause.
Note that Hume is here supposing that, in our idea of the relationbetween cause and effect, the “tye or connexion … whichbinds them together” is necessary (“it is impossible thatany other effect could result”). In the corresponding section ofthe Treatise, Book 1, part 3, section 2 (“Ofprobability; and of the idea of cause and effect”), Hume makesthis completely explicit (T 1.3.2.11; SBN 77):
Shall we then rest contented with these two relations of contiguityand succession, as affording a compleat idea of causation? By nomeans. An object may be continuous and prior to another, without beingconsider’d as its cause. There is a NECESSARY CONNEXION to betaken into consideration; and that relation is of much greaterimportance, than any of the other two above-mention’d.
In the Enquiry, section 4, part 2, Hume presents his famousskeptical argument concerning causation and induction. Since we need“experience” (i.e., the observation of constantconjunctions) to make any causal claims, Hume now asks (EHU 4.14; SBN32): “What is the foundation of all conclusions fromexperience?” The conclusion from an experience of constantconjunction is an inference to what has not yet been observed fromwhat has already been observed, and Hume finds an unbridgeable gapbetween the premise (summarizing what we have observed so far) and the(not yet observed) conclusion of this inference (EHU 4.16; SBN 34):
These two propositions are far from being the same, I have foundthat such an object has always been attended with such an effect,and I foresee, that other objects, which are, in appearance,similar, will be attended with similar effects.
Hume concludes that this inference has no foundation in theunderstanding—that is, no foundation in what he calls “reasoning”.[5] How does Hume arrive at this position?
All our inductive inferences—our “conclusions fromexperience”—are founded on the supposition that the courseof nature is sufficiently uniform so that the future will beconformable to the past (EHU 4.21; SBN 37–38):
For all inferences from experience suppose, as their foundation, thatthe future will resemble the past …. If there be any suspicion,that the course of nature may change, and that the past may be no rulefor the future, all experience becomes useless, and can give rise tono inference or conclusion.
Therefore, what Hume is now seeking, in turn, is the foundation in ourreasoning for the supposition that nature is sufficiently uniform.
Section 4, part 1 of the Enquiry distinguishes (as we haveseen) between reasoning concerning relations of ideas and reasoningconcerning matters of fact and existence. Demonstrative reasoning(concerning relations of ideas) cannot establish the supposition inquestion,
since it implies no contradiction, that the course of nature maychange, and that an object, seemingly like those which we haveexperienced, may be attended with different or contrary effects. (EHU4.18; SBN 35)
Moreover, reasoning concerning matters of fact and existence cannotestablish it either, since such reasoning is always founded on therelation of cause and effect, the very relation we are now attemptingto found in reasoning (EHU 4.19; SBN 35–36):
We have said, that all arguments concerning existence are founded onthe relation of cause and effect; that our knowledge of that relationis derived entirely from experience; and that all our experimentalconclusions proceed upon the supposition, that the future will beconformable to the past. To endeavour, therefore, the proof of thislast proposition by probable arguments, or arguments regardingexistence, must be evidently going in a circle, and taking that forgranted, which is the very point in question.[6]
Although Hume has now shown that there is no foundation for thesupposition that nature is sufficiently uniform in reasoning or theunderstanding, he goes on, in the following section 5 of theEnquiry (“Skeptical Solution of these Doubts”),to insist that we are nonetheless always determined to proceed inaccordance with this supposition. There is a natural basis or“principle” for all our arguments from experience, even ifthere is no ultimate foundation in reasoning (EHU 5.4–5; SBN42–43):
And though [one] should be convinced, that his understanding has nopart in the operation, he would nonetheless continue in the samecourse of thinking. There is some other principle, which determineshim to form such a conclusion. This principle is CUSTOM or HABIT. Forwherever the repetition of any particular act or operation produces apropensity to renew the same act or operation, without being impelledby any reasoning or process of the understanding; we always say, thatthis propensity is the effect of Custom. By employing thatword, we pretend not to have given the ultimate reason of such apropensity. We only point out a principle of human nature, which isuniversally acknowledged, and which is well known by its effects.[7]
In section 7 of the Enquiry (“On the Idea of NecessaryConnexion”), after rejecting the received views of causalnecessity, Hume explains that precisely this custom or habit alsoproduces our idea of necessary connection (EHU 7.28; SBN 75):
It appears, then, that this idea of a necessary connexion among eventsarises from a number of similar instances which occur of the constantconjunction of these events; nor can that idea ever be suggested byany one of these instances, surveyed in all possible lights andpositions. But there is nothing in a number of instances, differentfrom every single instance, which is supposed to be exactly similar;except only, that after a repetition of similar instances, the mind iscarried by habit, upon the appearance of one event, to expect itsusual attendant, and to believe that it will exist. This connexion,therefore, which we feel in the mind, this customarytransition of the imagination from one object to its usual attendant,is the sentiment or impression, from which we form the idea of poweror necessary connexion.
Thus, the custom or habit to make the inductive inference not onlygives rise to a new idea of not yet observed instances resembling theinstances we have already observed, it also produces a feeling ofdetermination to make the very inductive inference in question. Thisfeeling of determination, in turn, gives rise to a further new idea,the idea of necessary connexion, which has no resemblance whatsoeverwith anything we have observed. It is derived from an“impression of reflection” (an internal feeling orsentiment), not from an “impression of sensation” (anobserved instance before the mind), and it is in precisely this sense,for Hume, that the idea of necessary connection is merely subjective.Hume emphasizes that this is a “discovery” both “newand extraordinary”, and that it is skeptical in character (EHU7.28–29; SBN 76):
No conclusions can be more agreeable to scepticism than such as makediscoveries concerning the weakness and narrow limits of human reasonand capacity. And what stronger instance can be produced of thesurprising ignorance and weakness of the understanding, than thepresent? For surely, if there be any relation among objects, which itimports to us to know perfectly, it is that of cause and effect.
Kant agrees with Hume that neither the relation of cause and effectnor the idea of necessary connection is given in our sensoryperceptions; both, in an important sense, are contributed by our mind.For Kant, however, the concepts of both causality and necessity arisefrom precisely the operations of our understanding—and, indeed,they arise entirely a priori as pure concepts or categories of theunderstanding. It is in precisely this way that Kant thinks that hehas an answer to Hume’s skeptical problem of induction: theproblem, in Kant’s terms, of grounding the transition frommerely “comparative” to “strict universality”(A91–92/B123–124). Thus in § 29 of theProlegomena, as we have seen, Kant begins from a merelysubjective “empirical rule” of constant conjunction orassociation among our perceptions (of heat following illumination bythe sun), which is then transformed into a “necessary anduniversally valid law” by adding the a priori concept ofcause.
At the end of our discussion in section 1 above we saw that there is aserious difficulty in understanding what Kant intends here—adifficulty to which he himself explicitly calls attention. Kant doesnot think that the particular causal law that “the sun isthrough its light the cause of heat” is itself a synthetic apriori truth. Indeed, the very same difficulty is present in ourdiscussion at the beginning of this section. For, what Kant is sayingin § II of the second edition of the Introduction to theCritique is that necessity and strict universality are“secure criteria of an a priori cognition” (B4;emphasis added). More specifically (B3):
Experience in fact teaches us that something is constituted thus andso, but not that it cannot be otherwise. Hence, if … aproposition is thought together with its necessity, then itis an a priori judgment.
Yet, once again, Kant does not think that particular causal lawsrelating specific causes to specific effects are all (synthetic) apriori. Accordingly, when Kant provides examples of (synthetic) apriori cognitions in the immediately following paragraph, he cites thesynthetic a priori principle of the Second Analogy of Experience(“All alterations take place in accordance with the law of theconnection of cause and effect” [B232]) rather than anyparticular causal law (B4–5):
Now it is easy to show that there actually are such judgments in humancognition which are necessary and in the strictest sense universal,and therefore purely a priori. If one wants an example from thesciences, then one need only take a look at any of the propositions ofmathematics. If one wants such an example from the most common use ofthe understanding, then the proposition that every alteration musthave a cause can serve.
On the basis of this important passage, among others, the majority oftwentieth-century English-language commentators have rejected the ideathat Kant has a genuine disagreement with Hume over the status ofparticular causal laws. One must sharply distinguish between thegeneral principle of causality of the Second Analogy—theprinciple that every event b must have a causea—and particular causal laws: particular instantiationsof the claim that all events of type A must always befollowed by events of type B. The former is in fact asynthetic a priori necessary truth holding as a transcendentalprinciple of nature in general, and this principle is explicitlyestablished in the Second Analogy. But the Second Analogy does notestablish, on this view, that particular causal laws are themselvesnecessary. Indeed, as far as particular causal laws are concerned, theSecond Analogy is in basic agreement with Hume: they (as synthetica posteriori) are established by induction and by induction alone.[8]
It is indeed crucially important to distinguish between the generalprinciple of causality Kant establishes in the Second Analogy andparticular causal laws. It is equally important that particular causallaws, for Kant, are (at least for the most part) synthetic aposteriori rather than synthetic a priori. It does not follow,however, that Kant agrees with Hume about the status of synthetic aposteriori causal laws. On the contrary, Kant (as we have seen)clearly states, in § 29 of the Prolegomena (the verypassage where he gives his official “answer to Hume”),that there is a fundamental difference between a mere “empiricalrule” (heat always follows illumination by the sun) and agenuine objective law (the sun is through its light the cause of heat)arrived at by adding the a priori concept of cause to the merelyinductive rule. Any law thus obtained is “necessary anduniversally valid”, or, as Kant also puts it, we are now inpossession of “completely and thus necessarily validrules”. In such cases (A91/B124):
The succession is necessary; … the effect does notmerely follow upon the cause but is posited through it andfollows from it. The strict universality of the rule iscertainly not a property of empirical rules, which, through induction,can acquire nothing but comparative universality: i.e., extensiveutility.
Therefore, it is by no means the case that Kant simply agrees withHume that particular causal laws are grounded solely on induction and,accordingly, that the necessity we attribute to particular causalconnections is merely subjective.
Similarly, the text of the Second Analogy is also committed to thenecessity and strict universality of particular causal laws. If thegeneral causal principle (that every event b must have acause a) is true, then, according to Kant, there must also beparticular causal laws (relating preceding events of type Ato succeeding events of type B) which are themselves strictlyuniversal and necessary.[9] Kant maintains that, when one event follows another in virtue of acausal relation, it must always follow “in accordance with arule” (A193/B238). Moreover, the “rule” to whichKant is here referring is not the general causal principle, but rathera particular law connecting a given cause to a given effect which isitself strictly universal and necessary (A193/B238–239):
In accordance with such a rule, there must thus lie in that whichprecedes an event in general the condition for a rule according to whichthis event follows always and necessarily.
Kant insists on this point throughout the Second Analogy:
that which follows or happens must follow according to a universalrule from that which was contained in the previous state,(A200/B245)
in that which precedes the condition is to be met with under which theevent always (i.e., necessarily) follows, (A200/B246)
and so on. One cannot escape the burden of explaining the apparentlyparadoxical necessity and universal validity of particular (synthetic)a posteriori causal laws simply by distinguishing them fromthe general (synthetic) a priori causal principle.
What is the relationship, then, between the general causal principleof the Second Analogy and the particular causal laws whose existence,according to Kant, is required by the causal principle? What, moregenerally, is the relationship between the transcendental synthetic apriori principles of the understanding (including all three Analogiesof Experience—compare the end of note 3 above—as well as the principles corresponding to the othercategories) and the more particular synthetic a posteriori laws ofnature involved in specific causal relationships governing empiricallycharacterized events and processes? The relationship cannot bedeductive; for, if one could deductively derive the particular causallaws from the transcendental principles of the understanding, then theformer would have to be synthetic a priori as well.
Kant himself discusses this relationship extensively, beginning in thefirst edition version of the Transcendental Deduction(A126–128):
Although we learn many laws through experience, these are still onlyparticular determinations of yet higher laws, among which the highest(under which all others stand) originate a priori in the understandingitself, and are not borrowed from experience, but must rather provideappearances with their law-governedness, and precisely thereby makeexperience possible … To be sure, empirical laws as such can inno way derive their origin from pure understanding—no more thanthe immeasurable manifold of appearances can be sufficientlycomprehended from the pure form of sensibility. But all empirical lawsare only particular determinations of the pure laws of theunderstanding, under which and in accordance with the norm of whichthey first become possible, and the appearances take on a lawfulform—just as all appearances, notwithstanding the diversity oftheir empirical form, still must also always be in accordance with thecondition of the pure form of sensibility [i.e., space and time].
The “pure laws of the understanding” (here and elsewhere)refers to the pure transcendental principles of theunderstanding characterizing what Kant calls “experience ingeneral” or “nature in general”.
In the second edition version Kant makes essentially the same point,this time explicitly stating that the relationship in question is notdeductive (B165):
The pure faculty of understanding, however, is not sufficient forprescribing to appearances a priori, through mere categories, any lawsother than those which are involved in a nature in general,as the law-governedness of all appearances in space and time.Particular laws, because they concern empirically determinedappearances, can not be completely derived therefrom,although they one and all stand under them. Experience must be addedin order to become acquainted with the [particular laws] assuch, but only the former laws provide a priori instructionconcerning experience in general, and [concerning] that which can becognized as an object of experience.
But what exactly does it mean for particular laws of nature to“stand under” the a priori principles of theunderstanding—that is, to be what Kant calls “particulardeterminations” of these principles? Once again, it will takemore work fully to clarify this relationship, but we can meanwhileobserve that it is precisely in virtue of the relationship in questionthat empirical causal connections—empirical causal laws ofnature—count as necessary for Kant.
The necessity in question is characterized in Kant’s officialdiscussion of the category of necessity in the Postulates ofEmpirical Thought—the three principles corresponding to thecategories of possibility, actuality, and necessity(A218–218/B265–266):
- That which agrees with the formal conditions of experience(according to intuition and concepts), is possible.
- That which coheres with the material conditions of experience(with sensation), is actual.
- That whose coherence with the actual is determined in accordancewith the general conditions of experience, is (exists as)necessary.
The “formal [or “general”] conditions ofexperience” include the forms of intuition (space and time),together with all the categories and principles of the understanding.The material conditions of experience include that which is given tous, through sensation, in perception. Kant is thus describing athree-stage procedure, in which we begin with the formal a prioriconditions of the possibility of experience in general,perceive various actual events and processes by means ofsensation, and then assemble these events and processestogether—via necessary connections—by means ofthe general conditions of the possibility of experience with which webegan.
In his detailed discussion of the third Postulate Kant makes it clearthat he is referring, more specifically, to causal necessity,and to particular (empirical) causal laws(A226–8/B279–80):
Finally, as far as the third Postulate is concerned, itpertains to material necessity in existence, and not the merely formaland logical necessity in the connection of concepts. … Nowthere is no existence that could be cognized as necessary under thecondition of other given appearances except the existence of effectsfrom given causes in accordance with laws of causality. Thus, it isnot the existence of things (substances), but only that of theirstate, about which we can cognize their necessity—and, indeed,from other states that are given in perception, in accordance withempirical laws of causality.
Note that, in this passage, Kant refers to “laws ofcausality” (in the plural) in the second quoted sentence, and“empirical laws of causality” (again in the plural) in thelast sentence. Hence, he is here referring to particular causal laws(of the form every event of type A must always be followed byan event of type B) rather than the general principle of theSecond Analogy (that every event b must have a cause a).[10]
In the Transcendental Deduction (as we have seen) Kant says that
all empirical laws are only particular determinations of the pure lawsof the understanding, under which and in accordance with the norm ofwhich they first become possible, and the appearances take on a lawfulform. (A127–128)
In the discussion of the third Postulate Kant says that we can cognizean effect as necessary on the basis of an empirical lawrelating it to its cause—where the effect’s“connection with the actual is determined in accordance with thegeneral conditions of experience” (A218/B266). Kant issuggesting, therefore, that the precise sense in which particularempirical laws themselves become necessary is that they, too, are“determined” in relation to actual perceptions “inaccordance with the general conditions of experience” (where thelatter, of course, essentially include the “pure laws of theunderstanding”, i.e., the principles).
Thus, in the example from § 29 of the Prolegomena, Kantbegins from a mere “empirical rule” (that heat alwaysfollows illumination by the sun) and then proceeds to a“necessary and universally valid” law by adding the apriori concept of cause to this (so far) merely inductive rule. Thevery same three-stage procedure described by the three Postulates as awhole—in which we begin with the formal a priori conditions ofthe possibility of experience in general, perceive variousactual events and processes by means of sensation, and thenassemble these events and processes together (via necessaryconnections) by means of the a priori conditions of the possibility ofexperience—also results in “necessary and universallyvalid” empirical causal laws of nature (the sun is through itslight the cause of heat) governing the events and processes inquestion.
3. Kant, Hume, and the Newtonian Science of Nature
In § 36 of the Prolegomena (after he has presented hisofficial “answer to Hume” in § 29) Kant addresses thequestion of the relationship between particular empirical laws and thea priori principles of the understanding under the title “How isnature itself possible?” Nature in the material senseis “the totality of all appearances” given in space andtime (4, 318; 69). Nature in the formal sense is “thetotality of rules under which all appearances must stand if they areto be thought as connected in an experience” (4, 318; 70). Inanswering the question of how nature in the formal sense is possibleKant proceeds to distinguish between “empirical laws of nature,which always presuppose particular perceptions” and
the pure or universal laws of nature, which, without having a basis inparticular perceptions, contain merely the conditions of theirnecessary unification in an experience. (4, 320; 71)
Yet (as we have seen) the empirical laws owe their status as“necessary and universally valid” to their relationshipwith the a priori “pure or universal” laws (principles) ofthe understanding. Moreover, Kant illustrates this situation with anexample, which (as explained in the very brief § 37)
is to show, that laws that we discover in objects of sensibleintuition, especially if they are cognized as necessary, are alreadytaken by us to be such as the understanding has put there, even thoughthey are otherwise similar in all respects to laws of nature that weattribute to experience. (4, 320; 72)
The example (presented in the immediately following § 38) is a
physical law of mutual attraction, extending over the whole ofmaterial nature, whose rule is that it diminishes inversely with thesquare of the distances from every attracting point. (4, 321; 73)
Thus, Kant illustrates his conception of the relationship betweenparticular empirical laws and the a priori principles of theunderstanding with the Newtonian law of universal gravitation.[11]
In § VI of the Introduction to the second edition of theCritique, where Kant discusses the “general problem ofpure reason” (“How are synthetic a priori judgmentspossible?”), Kant explains that
in the solution of [this] problem there is also conceived, at the sametime, the possibility of the pure employment of reason in groundingand developing all sciences that contain a theoretical a prioricognition of objects, i.e., the answer to the questions: Howis pure mathematics possible? How is pure natural sciencepossible?. (B20)
Kant illustrates his contention that propositions of “purenatural science” actually exist in a footnote (ibid.):
One need only attend to the various propositions that appear at thebeginning of proper (empirical) physics, such as those of thepermanence of the same quantity of matter, of inertia, of the equalityof action and reaction, and so on, in order to be soon convinced thatthey constitute a pure (or rational) physics, which well deserves, asa science of its own, to be isolated and established in its entireextent, be it narrow or wide.
Kant had just completed the latter task, in fact, in hisMetaphysical Foundations of Natural Science, which hadmeanwhile appeared in 1786 (following the publication of theProlegomena in 1783 and immediately preceding the publicationof the second edition of the Critique in 1787). There Kantarticulates what he calls “pure natural science” in fourchapters corresponding, respectively, to the four headings of thetable of categories (quantity, quality, relation, and modality). Inthe third chapter or Mechanics (corresponding to the three categoriesof relation: substance, causality, and community) Kant derives three“laws of mechanics” corresponding, respectively, to thethree Analogies of Experience: the permanence or conservation of thetotal quantity of matter, the law of inertia, and the equality ofaction and reaction—which Kant describes as a law of “thecommunication of motion” (4, 544; 84). All these laws, Kantmakes clear, are synthetic a priori propositions, demonstrated apriori and “drawn from the essence of the thinking facultyitself” (4, 472; 8).
For Kant, therefore, the laws of the Newtonian science of nature areof two essentially different kinds. Kant regards Newton’s three“Axioms or Laws of Motion” presented at the beginning ofthe Principia as synthetic a priori truths—which Kanthimself attempts to demonstrate a priori in the Metaphysical Foundations.[12] By contrast, Kant does not regard the inverse-square law of universalgravitation, which Newton establishes by a famous “deductionfrom the phenomena” in Book 3 of the Principia, as asynthetic a priori truth—and, accordingly, Kant does not attemptto demonstrate this law a priori in the MetaphysicalFoundations. Nevertheless, Kant regards the synthetic aposteriori law of universal gravitation as “necessary anduniversally valid” in virtue of the way in which it is“determined” in relation to the “phenomena” bythe synthetic a priori laws of pure natural science. And, since thelatter, in turn, are “determined” from the a prioriprinciples of the understanding, the a posteriori law of universalgravitation is thereby “determined” in relation to actualperceptions “in accordance with the general conditions of experience”.[13]
We shall return to Kant’s conception of Newtonian naturalscience below, but we first want to discuss Hume’s ratherdifferent debt to Newton. Hume, like virtually everyone else in theeighteenth century (including Kant), takes Newtonian natural scienceas his model, and, indeed, he attempts to develop his own“science of human nature” following Newton’sexample. Yet Hume learns a very different lesson from Newton than doesKant, based on Newtonian inductivism rather than Newtonianmathematical demonstrations. Contrasting Hume and Kant on this pointgreatly illuminates their diverging conceptions of causation andnecessity.
To begin with, Hume does not consider Newton’s “Axioms orLaws of Motion” as a priori in any sense (in Kant’sterminology, neither analytic nor synthetic a priori). All of theselaws, according to Hume, are simply “facts” inductivelyderived from (constant and regular) experience. Hume considersNewton’s second law of motion (F = ma) in the Enquiry,section 4, part 1 (EHU 4.13; SBN 31):
Thus, it is a law of motion, discovered by experience, that the momentor force of any body in motion is in the compound ratio or proportionof its solid contents and its velocity … . Geometry assists usin the application of this law … ; but still the discovery ofthe law itself is owing merely to experience, and all the abstractreasonings in the world could never lead us one step towards theknowledge of it.
One of Newton’s main examples of the third law of motion is thecommunication of motion by impact or impulse.[14] Hume considers such communication of motion in the same section ofthe Enquiry (EHU 4.8; SBN 28–29):
We are apt to imagine, that we could discover these effects by themere operation of our reason, without experience. We fancy, that werewe brought, on a sudden, into this world, we would at first haveinferred, that one billiard ball would communicate motion to anotherupon impulse; and that we needed not to have waited for the event, inorder to pronounce with certainty concerning it. Such is the influenceof custom, that, where it is strongest, it not only covers our naturalignorance, but even conceals itself, and seems not to take place,merely because it is found in the highest degree.
Finally, in a footnote at the end of part 1 of section 7 (the sectionin the Enquiry devoted to the idea of necessary connection),Hume considers the law of inertia (EHU 7.25n16; SBN 73n1):
I need not examine at length the vis inertiae which is somuch talked of in the new philosophy, and which is ascribed to matter.We find by experience, that a body at rest or in motion continues forever in its present state, till put from it by some new cause; andthat a body impelled takes as much motion from the impelling body asit acquires itself. These are facts. When we call this a visinertiae, we only mark these facts, without pretending to haveany idea of the inert power.
(Hume here puts the law of inertia and the communication of motion byimpulse together, because both are consequences of a body’s“inherent force [vis insita]” or “inertforce [vis inertiae”] according to Newton’s thirddefinition preceding the Laws of Motion.[15]) It is clear, therefore, that Hume views all of Newton’s laws ofmotion as inductively derived empirical propositions, which(deceptively) appear to be derived from reason simply because theconstant and regular experience on which they are in fact based is sopervasive.
We believe that Hume’s discussion of the communication of motionby contact or impulse shows his debt to Newton especially clearly. Insection 7, part 1 of the Enquiry Hume is criticizing theinherited ideas of necessary connection. We believe that both here andin section 4, part 1, where he rejects any a priori demonstration ofcausality, Hume is centrally concerned with the conception ofnecessary connection articulated by the mechanical natural philosophy.This philosophy had taken the communication of motion by contact orimpulse as the paradigm of an a priori rationally intelligible causalconnection, to which all other instances of causal connection must bereduced. The reduction would take place by reducing all observablecausal relationships to the motions and impacts of the tinymicroscopic parts of bodies.[16]
In the view of contemporary mechanical philosophers, especiallyHuygens and Leibniz, Newton’s conception of universalgravitation involved an entirely unintelligible action at a distanceacross empty space. Gravitation could only be acceptable, on theirview, if it were explained, in turn, by vortices of interveninginvisible matter whose tiny microscopic particles effected theapparent attraction of bodies via impulse. Although both Leibniz andHuygens accepted Newton’s demonstration that the orbits of thesatellites of the major astronomical bodies in the solar system obeythe inverse-square law (the planets with respect to the sun, the moonsof Jupiter and Saturn with respect to their planets, the earth’smoon with respect to the earth), they rejected Newton’sunrestricted generalization of this law to hold between all bodies(and all parts of bodies) whatsoever. For them, the inverse-square lawcould be accepted in astronomy only by taking the major bodies of thesolar system as each being surrounded by vortices limited to thefinite surrounding region of their satellites. The validity of theinverse-square law would thus be restricted to precisely such a finiteregion, so that it could not be extended arbitrarily far: the moons ofJupiter would accelerate towards Jupiter, for example, but neitherSaturn nor the sun, for example, would experience such accelerationstowards Jupiter.[17]
In the second (1713) edition of the Principia, in response tothese doubts about the law of universal gravitation raised bymechanical philosophers, Newton adds an explicit principle ofunrestricted inductive generalization—Rule 3—to a set of“Rules for the Study of Natural Philosophy” at thebeginning of Book 3. Rule 3 states (Principia, 795):
Those qualities of bodies that cannot be intended and remitted [i.e.qualities that cannot be increased and diminished] and that belong toall bodies on which experiments can be made should be taken asqualities of all bodies universally.[18]
Then, in the explanation of this Rule, Newton depicts the hypothesesof the mechanical philosophy as in conflict with the method ofinductive generalization that leads to the law of universalgravitation (Principia, 795–796):
For the qualities of bodies can be known only through experiments; andtherefore qualities that square with experiments universally are to beregarded as universal qualities …. Certainly idle fancies oughtnot to be fabricated recklessly against the evidence of experiments,nor should we depart from the analogy of nature, since nature isalways simple and ever consonant with itself.
That the “idle fancies” in question include the hypothesesof the mechanical philosophers (such as the vortex hypothesis) is madeperfectly clear and explicit in the passage from the General Scholium(also added to the second edition in 1713) where Newton famously saysthat he “feigns” no hypotheses (Principia, 943):
I have not as yet been able to deduce from phenomena the reason for[the] properties of gravity, and I do not feign hypotheses. Forwhatever is not deduced from the phenomena must be called ahypothesis; and hypotheses, whether metaphysical or physical, or basedon occult qualities, or mechanical, have no place in experimentalphilosophy. In this experimental philosophy, propositions are deducedfrom the phenomena and are made general by induction. Theimpenetrability, mobility, and impetus of bodies, and the laws ofmotion and the law of gravitation have been found by this method.[19]
Thus, Newton also makes it clear that gravity is (at least) as wellgrounded by induction as the favored properties of bodies singled outby the mechanical philosophers (impenetrability, motion, and impetus),all of which have been derived inductively from phenomena (apoint he had earlier developed in the explanation of Rule 3).[20]
Hume (as we have seen) considers all the laws ofmotion—including the communication of motion by contact orimpulse—as (merely) inductively derived general principles.Accordingly, Hume also unreservedly accepts universal gravitation andtakes Newton’s theory to articulate a fundamental law of naturecompletely on a par with all other inductively established laws (EHU6.4; SBN 57):
There are some causes, which are entirely uniform and constant inproducing a particular effect; and no instance has ever yet been foundof any failure or irregularity in their operation. Fire has alwaysburned, and water suffocated every human creature: The production ofmotion by impulse and gravity is an universal law, which has hithertoadmitted of no exception.
For Hume, contrary to the mechanical philosophy, there is no asymmetrybetween the law of universal gravitation and the laws of impact withrespect to their intrinsic intelligibility.[21]
There is an even more fundamental relationship between Hume’sconception of the inductive method and Newton’s Rule 3. In theexplanation of this Rule (as we have seen) Newton takes thesupposition that “nature is always simple and ever consonantwith itself” to license the inductive generalizations made inaccordance with the Rule. Similarly, Hume appeals, in theEnquiry, to the supposition that “the course ofnature” does not change (EHU 4.21; SBN 37–38) or,equivalently, that “the future will be conformable to thepast” (EHU 4.19; SBN 35–36). In the Treatise Humeformulates this supposition as the
principle, that instances, of which we have had no experience,must resemble those, of which we have had experience, and that thecourse of nature continues always uniformly the same. (T 1.3.6.4;SBN 89)
Hume takes this supposition to license (in his own words, to providethe “foundation” for: compare note 5 above) all inductive inferences from observed constant conjunctions,just as Newton takes the supposition that “nature is alwayssimple and ever consonant with itself” to license theapplications of his Rule 3. It appears very likely, therefore, thatHume takes this Newtonian supposition as the model for his ownprinciple of the uniformity of nature.[22]
Yet Hume raises radical skeptical doubts about this very principle. Ithas no foundation in reasoning: neither in demonstrative reasoning nor(on pain of circularity) in inductive reasoning itself. Nevertheless,as firmly based in custom or habit, it is a universal principle of thehuman mind. Moreover, it is also the foundation for the best availablescience of matters of fact—Newtonian inductive science—andfor Hume’s own inductive science (self-consciously followingNewton) of human nature.[23] Thus, when Hume sets his radical skeptical doubts aside, theapplication of our foremost empirical scientific method (based onuniform constant conjunction) has normative force, and it therebyleads to the articulation of universal, exceptionless laws of naturewhich, as such, we are compelled to treat as necessary untilexperience teaches us otherwise (in accordance with Newton’sRule 4 in Book 3 of the Principia: see note 19 above).[24] It is because the idea of necessaryconnection, for Hume, arises from the application of the Newtonianinductive method that our projection of an inner feeling ofdetermination onto nature does not merely reduce to a blindinstinctual disposition, but amounts to a normative methodologicalstandard in our best scientific understanding of nature.[25]
In the famous hypothesis non fingo passage from the GeneralScholium Newton characterizes his “experimental” method asfollows (Principia, 943): “In this experimentalphilosophy, propositions are deduced from the phenomena and are madegeneral by induction”. Hume focusses exclusively on the second,inductive, clause, and he thereby shows an especially deep insightinto the fundamental difference between Newton’s methodology andthe purely demonstrative ideal of scientific knowledge represented bythe mechanical philosophy.[26] For Kant, by contrast, the dispute between Newton and the mechanicalphilosophers is now effectively over; and Kant concentrates instead onNewtonian mathematical demonstrations and the idea of “deductionfrom phenomena”. This comes out especially clearly in theMetaphysical Foundations of Natural Science, where Kantengages with some of the most important details of Newton’sdemonstration of the law of universal gravitation from the initial“phenomena” described at the beginning of Book 3 of thePrincipia. Kant shows especially deep insight into the way inwhich this argument is inextricably entangled, in turn, with theNewtonian mathematical conception of (absolute) space, time, andmotion; and he thereby takes special pains to frame the explicitlyinductive steps in Newton’s argument within the a priori“special metaphysics” of nature expounded in theMetaphysical Foundations.[27]
The “phenomena” with which Book 3 of thePrincipia begins record the observed relative motions of theprincipal satellites in the solar system with respect to their primarybodies (the planets with respect to the sun, the moons of Jupiter andSaturn with respect to their planets, the earth’s moon withrespect to the earth). All of these satellites obey Kepler’slaws (at the time often called “rules”) of orbital motion;and, appealing to his first law of motion (the law of inertia), Newtonis able to derive purely mathematically that each of the satellites inquestion experiences an inverse-square acceleration directed towardsits respective primary body. Moreover, the so-called “moontest” (developed in Proposition 4 of Book 3) shows that theinverse-square acceleration governing the moon’s orbit is, whenthe distance in question approaches the surface of the earth,numerically equal to the constant acceleration of terrestrial gravityfiguring in Galileo’s law of fall. Newton concludes (by thefirst and second of his Rules for the Study of Natural Philosophy)that the (centripetal) force holding the moon in its orbit is the sameforce as terrestrial gravity.
The crucial inductive steps come next. Newton generalizes the resultof the moon test to all the other satellites in the solar system:they, too, are held in their orbits by the same force of gravity(Proposition 5). Then (in Proposition 6) Newton concludes that allbodies whatsoever gravitate towards every primary body (including bothSaturn and the sun towards Jupiter, for example); moreover, theirweights, like those of terrestrial bodies, are proportional to theirmasses at equal distances from the primary body in question.[28] Finally (in Proposition 7), Newton applies the third law of motion tothis last result to derive the law of universal gravitation itself:not only do all bodies whatsoever experience inverse-squareaccelerations (proportional to mass) towards every primary body in thesolar system, but the primary bodies themselves experienceinverse-square accelerations (proportional to mass) towards everyother body (Jupiter towards its moons and all other planets, the earthtowards its moon and all other planets, and so on).[29] Indeed, Newton here extends this universal conclusion to theparts of all bodies as well.[30]
Kant accepts Newton’s law of gravitation in its full universalform—as a
physical law of mutual attraction, extending over the whole ofmaterial nature, whose rule is that it diminishes inversely with thesquare of the distances from every attracting point.(Prolegomena, § 38: 4, 321; 73)
Moreover, Kant has no qualms at all about action at a distance, and heeven attempts to demonstrate a priori (in the MetaphysicalFoundations) that universal gravitation, as a manifestation ofwhat he calls the “original” or “fundamental”force of attraction, must be conceived as an immediate actionat a distance through empty space.[31] Kant also attempts to demonstrate his three “laws ofmechanics” corresponding to Newton’s three laws of motionas synthetic a priori truths, especially the crucially important thirdlaw (the equality of action and reaction).[32] Whereas Newton had devoted considerable effort to producingexperimental evidence for this law (see note 14 above), Kant here ventures a rare criticism of Newton for not havingthe courage to prove it a priori.[33] Indeed, regarding this particular law as a synthetic a priori truthis central to Kant’s reinterpretation of the Newtonian conceptsof (absolute) space, time, and motion; for it is in virtue of hisunderstanding of the equality of action and reaction that Kant is nowable simply to define the center of gravity of the solarsystem (in which this principle necessarily holds) as an empiricallydeterminable (provisional) surrogate for Newtonian absolute space.[34] Moreover, and for closely related reasons, Kant takes theuniversality of what he calls the “original” or“fundamental” force of attraction—that it proceedsfrom every part of matter to every other part to infinity—asanother synthetic a priori truth demonstrable in “pure natural science”.[35]
Given this foundation in “pure natural science”, Kant thenreconstructs Newton’s “deduction from the phenomena”of the law of universal gravitation as follows. We begin, followingNewton, from the observable “phenomena” described byKepler’s “rules”. These “phenomena”, inKant’s terminology, are so far mere “appearances[Erscheinungen]”, which have not yet attained thestatus of “experience [Erfahrung]”.[36] Then, again simply following Newton, we can use the law of inertia toderive (purely mathematically) inverse-square accelerations of theirsatellites directed towards every primary body in the solar system.Once we have done this, however, we can now, from Kant’s pointof view, frame all of Newton’s explicitly inductive steps withinthe a priori “special metaphysics” of nature developed inthe Metaphysical Foundations. By demonstrating a priori histhree “laws of mechanics” corresponding to the threeAnalogies of Experience, Kant establishes that Newton’s three“Axioms or Laws of Motion” are synthetic a priori truths(compare notes 12 and 32 above). Further, by identifying the accelerations in question aseffects of what Kant calls the fundamental force of attraction, it nowfollows from Kant’s “special metaphysics” of(material) nature that these accelerations must hold immediatelybetween each part of matter and every other part of matter—and,accordingly, are also directly proportional to the mass.[37]
In the fourth chapter or Phenomenology of the MetaphysicalFoundations Kant connects this reconstruction of Newton’sargument with the modal categories of possibility, actuality, andnecessity—the very categories which (as we saw at the end of thesecond section above) make it possible for initially merely inductivegeneralizations (à la Hume) to acquire the status of necessarylaws. The first stage, where we simply record the“phenomena” described by Kepler’s“rules” (as mere “appearances”: note 36 above), corresponds to the category of possibility. The second stage,where we say that we here have instances of “true” (asopposed to merely “apparent”) rotation by appealing to thelaw of inertia, corresponds to the category of actuality.[38] In the third stage, finally, we apply the equality of action andreaction to the true centripetal accelerations correlated with suchtrue rotations (note 38 above); and all of them, in accordance with Kant’s metaphysical“dynamical theory of matter”, must now be taken asextending universally to infinity from each attracting point (comparenotes 35 and 37 above). The result is the law of universal gravitation, now seen asfalling under the category of necessity. In this way, Kant’sreconstruction of Newton’s “deduction” of the law ofuniversal gravitation from the initial Keplerian“phenomena” provides a perfect illustration of thethree-step procedure, described in the Postulates of EmpiricalThought, by which a mere “empirical rule” is transformedinto a “necessary and universally valid” objective law.[39]
4. Time Determination, the Analogies of Experience, and the Unity of Nature
We have suggested that Kant’s reconstruction of Newton’s“deduction from the phenomena” of the law of universalgravitation in the Metaphysical Foundations of NaturalScience is inextricably entangled with his reinterpretation ofthe Newtonian concepts of (absolute) space, time, and motion.[40] Indeed, Kant begins the Metaphysical Foundations by definingmatter as “the movable in space”—and by introducinga distinction between absolute and relative space which is clearlyderived from Newton’s Scholium on space, time, and motion at thebeginning of the Principia (see note 38 above). In Newton’s words (Principia, 408–409):
Absolute space, of its own nature without reference to anythingexternal, always remains homogeneous and immovable. Relative space isany movable measure or dimension of this absolute space.
In Kant’s words (4, 480; 15):
Matter is the movable in space. That space which isitself movable is called material, or also relative space.That space in which all motion must finally be thought (andwhich is therefore itself absolutely immovable) is called pure, oralso absolute space.
It turns out, however, that Kant’s own view, in apparentcontrast with Newton’s, is that “absolute space is initself nothing and no object at all”, but signifies only anindefinite process of considering ever more extended relative spaces(4, 481–482; 16–17). Moreover, when Kant returns to thisissue in the Phenomenology chapter (compare note 36 above), he states that
absolute space is therefore not necessary as the concept of an actualobject, but only as an idea, which is to serve as the rule forconsidering all motion and rest therein merely as relative. (4, 560;99)
Kant’s procedure for deriving “true motions” from“apparent motions” does not conceive true motions astaking place in a pre-given absolute space, but views them as theproduct of an indefinitely extended process of empirical determinationtaking place within experience itself: we begin from our parochialperspective here on the surface of the earth, proceed (in accordancewith the argument of Book 3 of Newton’s Principia) tothe center of gravity of the solar system, then proceed to the centerof gravity of the Milky Way galaxy, and so on ad infinitum.[41]
Similarly, it is a central theme of the Analogies of Experience in thefirst Critique that “absolutetime”—“time itself” (B219), “time foritself” (B225), or “time in itself” (B233)—isno actual object of perception. Hence, the three “modes oftime” (duration, succession, and simultaneity) must all bedetermined in and through perceptible features of the appearances.Kant calls this procedure “time determination” (moreprecisely, “the determination of the existence of appearances intime”), and he sums up his view as follows (A215/B262):
These, then, are the three analogies of experience. They are nothingelse but the principles for the determination of the existence ofappearances in time with respect to all of its three modes, therelation to time itself as a magnitude (the magnitude of existence,i.e., duration), the relation in time as a series (successively), andfinally [the relation] in time as a totality of all existence(simultaneously). This unity of time determination is thoroughlydynamical; that is, time is not viewed as that in which experienceimmediately determines the place of an existent, which is impossible,because absolute time is no object of perception by means of whichappearances could be bound together; rather, the rule of theunderstanding, by means of which alone the existence of theappearances can acquire synthetic unity with respect to temporalrelations, determines for each [appearance] its position in time, andthus [determines this] a priori and valid for each and every time.
For Kant, therefore, the temporal relations of duration, succession,and simultaneity cannot be viewed as pre-existing, as it were, in anabsolute time subsisting prior to and independently of the proceduresof our pure understanding for determining these relations within theappearances themselves. On the contrary, temporal relations as suchare the products of an empirical construction whereby we objectivelydetermine the appearances as objects of a unified experience by meansof the a priori principles of the Analogies. Thus, just as Kant doesnot view the determination of true motions from apparent motions astaking place within an infinite empty absolute space, he also rejectsan analogous conception of absolute time and replaces it, too, with aprocess of empirical determination taking place within experienceitself.
Indeed, there is an intimate relationship between these two proceduresfor empirical determination—of time and of motion, respectively.At the very beginning of his famous Scholium Newton distinguishesbetween “true” and merely “apparent” time(Principia, 408):
Absolute, true, and mathematical time, in and of itself and of its ownnature, without reference to anything external, flows uniformly and byanother name is called duration. Relative, apparent, and common timeis any sensible measure (whether accurate or nonuniform) of durationby means of motion: such a measure—for example, an hour, a day,a month, a year—is commonly used instead of true time.
Then, several pages later, Newton illustrates the difference between“absolute” and “relative” time with referenceto the celestial motions studied in astronomy (Principia,410):
In astronomy, absolute time is distinguished from relative time by theequation of common time. For natural days, which are commonlyconsidered equal for the purpose of measuring time, are actuallyunequal. Astronomers correct this inequality in order to measurecelestial motions on the basis of a truer time. It is possible thatthere is no uniform motion by which time may have an accurate measure.All motions can be accelerated and retarded, but the flow of absolutetime cannot be changed. The duration or perseverance of the existenceof things is the same, whether their motions are rapid or slow ornull; accordingly, duration is rightly distinguished from its sensiblemeasures and is gathered from them by means of an astronomicalequation.
Newton is here referring to the standard astronomical procedure,already well-understood in ancient astronomy, whereby we correct theordinary measure of time in terms of days, months, and years so as toobtain “sidereal” or mean solar time based on the motionsof the sun relative to both the earth and the fixed stars.[42]
In the Refutation of Idealism added to the second edition of theCritique Kant argues that all empirical determination oftime—including determination of the temporal relations amongone’s own inner states—ultimately depends on theperception of outer things, and, in particular, on the perception ofmotion in space (B277–278):
All empirical employment of our cognitive faculties in thedetermination of time fully agrees with this. It is not only that wecan undertake all time determination only by the change of externalrelations (motion) in relation to the permanent in space (e.g., motionof the sun with respect to objects on the earth), but we also havenothing at all permanent, which could underlie the concept of asubstance, as intuition, except merely matter, and even thispermanence is not derived from outer experience, but is ratherpresupposed a priori as necessary condition of all time determination,and thus also [of] the determination of inner sense with respect toour own existence by means of the existence of outer things.
In emphasizing that only matter can instantiate the conceptof substance here, Kant is alluding to the way in which theconservation of the total quantity of matter, in the MetaphysicalFoundations, realizes the (transcendental) principle of theconservation of substance.[43] Moreover, Kant’s language at B277–278 (we“undertake [vornehmen]” timedetermination by observing “motion of the sun with respect toobjects on the earth”) thereby suggests a progressive empiricalprocedure in which we begin with our perspective here on earth,measure the duration of time by the apparent motion of the sun, andthen proceed to correct this measure in light of our evolvingastronomical knowledge.[44]
For Kant, once again, this need for correction is not an indication ofa pre-existing absolute time subsisting prior to and independently ofour empirical procedures for determining temporal magnitudes fromobservable motions. It rather implies that empirically observablemotions must be subject to a priori principles of the understanding (apriori rules of time determination) in order to count as fullyobjective experience within a unified, temporally determinateobjective world. Applying the relevant principles of theunderstanding—the Analogies of Experience—thereforeresults in a sequence of successive corrections or refinements of ourordinary temporal experience, as the observable motions areprogressively embedded within an increasingly precise and refinedconception of temporality itself.
In the Metaphysical Foundations, in particular, Kantarticulates a specific realization of the Analogies of Experience interms of the Newtonian theory of universal gravitation. Kant’sthree “laws of mechanics” (a version of the Newtonian lawsof motion: compare notes 12 and 32 above) correspond to the three principles of the Analogies; thecategories of substance, causality, and community are realized by thesystem of Newtonian massive bodies interacting with one another in thecontext of what Newton, in Book III of the Principia, callsthe System of the World. The category of substance, that is, isrealized by the conservation of the total quantity of matter (mass) inall interactions involving these bodies (compare note 43 above, together with the sentence to which it is appended); thecategory of causality is realized by the gravitational forces throughwhich these interactions take place (in accordance with the law ofinertia); and the category of community is realized by thecircumstance that precisely these forces are everywhere mutuallyequal and opposite. The temporal relation of duration is therebyrealized by the progressive empirical procedure by which wesuccessively correct our ordinary measure of time in light of ourevolving astronomical knowledge (compare note 44 above, together with the sentence to which it is appended).[45] The temporal relation of succession is realized by the deterministicevolution of the motions of the bodies (masses) in question describedby the law of universal gravitation (according to which every laterstate of the system is uniquely determined by its earlier states).[46] The temporal relation of simultaneity, finally, is realized by thecircumstance that gravitational forces instantaneouslyconnect each body in the system with all other bodies.[47] It is in precisely this sense that the procedure of timedetermination Kant describes in the Analogies is intended to replacethe conception of a pre-given absolute time.
We have now arrived at the most fundamental divergence between Kantand Hume concerning causation and induction. For Hume, the order oftime is empirically given by the sequence of impressions and ideas(and associations among them) which in fact happen to appear beforethe mind. As Kant explains in the Second Analogy, however, such asequence, from his point of view, is
merely something subjective, and determines no object, andcan therefore in no way count as cognition of any object at all (noteven in the appearance). (A195/B240)
For Kant, it is only the a priori concept of causality (requiring anecessary rule of connection between preceding and succeeding events)which can then transform a merely subjective temporal sequence into anobjective one (ibid.):
If we thus experience that something happens, then we alwayspresuppose thereby that something precedes on which it follows inaccordance with a rule. For otherwise I would not say of the objectthat it follows, because the mere sequence in my apprehension, if itis not determined by means of a rule in relation to somethingpreceding, justifies no sequence in the object. Therefore, it isalways in reference to a rule, in accordance with which theappearances in their sequence (i.e., as they happen) are determinedthrough the previous state, that I make my subjective synthesis (ofapprehension) objective, and, it is solely under this presuppositionthat even the experience of something happening is possible.
It is for precisely this reason, Kant concludes, that mere inductionalone cannot be the ground for objective causalconnections—which presuppose both strict universality andnecessity, and therefore must be grounded on a priori concepts andprinciples of the pure understanding(A195–196/B240–241):
It seems, to be sure, that this contradicts all remarks that havealways been made concerning the course of the employment of ourunderstanding, according to which we have only been first guided bythe perception and comparison of many concurring sequences of eventsfollowing on certain appearances to discover a rule, in accordancewith which certain events always follow on certain appearances, and wehave thereby been first prompted to make for ourselves the concept ofcause. On such a basis this concept would be merely empirical, and therule it supplies, that everything that happens has a cause, would bejust as contingent as experience itself: its universality andnecessity would then be only feigned and would have no true universalvalidity, because they would not be grounded a priori but only oninduction.
For Kant, the concept of cause cannot possibly arise from a mererepetition of resembling constant conjunctions (“concurringsequences of events following on certain appearances”) producinga merely subjective custom.[48] The procedure by which we apply the concept of cause to experiencecannot be merely inductive in the Humean sense; it must rather involvea priori rules of the understanding through which we progressivelydetermine the objective causal relations between appearances—andthereby determine the objective order of succession in time itself.[49]
Kant thus has a completely different perspective from Hume’sconcerning the uniformity of nature. For Hume, the principle ofuniformity is a supposition implicit in all of our inductiveinferences leading to the formulation of laws of nature. If thisprinciple itself had a foundation in the understanding (in either apriori or a posteriori “reasoning”), then so would ourinductive inferences from observed constant conjunctions to so farunobserved events. Yet the supposition inquestion—“that instances, of which we have had noexperience, must resemble those, of which we have had experience, andthat the course of nature continues always uniformly thesame” (T 1.3.6.4; SBN 89)—cannot itself be justifiedby either demonstrative or inductive reasoning. In the former case itwould have to be self-contradictory to imagine that the course ofnature is not sufficiently uniform; in the latter the attemptedjustification would be viciously circular. The principle ofuniformity, however, is firmly based in custom or habit, as auniversal principle of the human mind, and it is also the foundationfor the Newtonian inductive method—including Hume’s owninductive science of the human mind. Although the principle thus hasnormative force in all our reasoning concerning matters of fact inboth science and common life, it cannot ultimately legitimate theattribution of objective necessity to our inductively established lawsof nature.[50]
Kant, in our view, is attempting to provide precisely such a groundingof objective necessity by means of the general principle of theAnalogies of Experience (B218): “Experience is possible only bymeans of the representation of a necessary connection ofperceptions”. More specifically, the Analogies of Experienceprovide an a priori conception of the unity and uniformity ofexperience playing the role, for Kant, of Hume’s principle ofthe uniformity of nature. According to the Analogies we know a priorithat nature in general must consist of interacting substances in spaceand time governed by universally valid and necessary causal lawsdetermining the temporal relations (of duration, succession, andsimultaneity) among all empirical events, and this articulated apriori conception of nature in general amounts to the knowledge thatnature is, in fact, sufficiently uniform.[51]
We can only have objective experience of particular events, for Kant,in so far as we simultaneously construct particular causal relationsamong them step by step, and this is only possible, in turn, in so faras we presuppose that they are one and all parts of a unified anduniform experience of nature in space and time governed by theAnalogies of Experience (together with the other principles of pureunderstanding). Moreover, since particular causal relations, for Kant,necessarily involve causal laws, all of our inferences from particularperceptions to universal causal laws of nature are grounded insynthetic a priori principles of pure understanding providing asynthetic a priori conception of the unity and uniformity of nature ingeneral. Hume was correct, therefore, that the principle of theuniformity of nature governs all of our inductive causal inferences;and he was also correct that this principle is not and cannot beanalytic a priori. What Hume did not see, from Kant’spoint of view, is that the merely comparative universality ofinductive generalization can indeed be overcome by transforminginitially merely subjective “empirical rules” into trulyobjective and necessary “universal laws” in accordancewith synthetic but still a priori principles of the unity ofnature in general.[52]
Bibliography
Primary Sources
Kant
Citations from Kant’s works, except for the Critique of PureReason, are by volume and page numbers of the Akademie edition ofKant’s gesammelte Schriften (Berlin, 1902—); theCritique of Pure Reason is cited by the standard A and Bpagination of the first (1781) and second (1787) editionsrespectively. Although all translations from Kant’s writings areour own, we follow the reference to the Akademie edition (except inthe case of the Critique of Pure Reason) with references tothe translations in the now standard Cambridge Edition of the Works ofImmanuel Kant, as follows:
- Critique of Pure Reason, translated and edited by PaulGuyer and Allen W. Wood (Cambridge: Cambridge University Press,1997).
- Prolegomena to Any Future Metaphysics, translated andedited by Gary Hatfield, revised edition (Cambridge: CambridgeUniversity Press, 2004).
- Metaphysical Foundations of Natural Science, translatedand edited by Michael Friedman (Cambridge: Cambridge University Press,2004).
- Theoretical Philosophy, 1755–1770, translated andedited by David Walford, in collaboration with Ralf Meerbote(Cambridge: Cambridge University Press, 1992). This volume containstranslations of Kant’s pre-critical writings, includingAttempt to Introduce the Concept of Negative Magnitudes intoPhilosophy (1763) and Dreams of a Spirit-Seer Explained byDreams of Metaphysics (1766).
Hume
- Citations from Hume’s A Treatise of Human Nature(abbreviated as T) are from the David Fate Norton and Mary J. Nortonedition (New York: Oxford University Press, 2000), and thus includebook, part, section, and paragraph numbers; we also add thecorresponding page numbers in the L. A. Selby-Bigge second edition(abbreviated as SBN), with revised text and notes by P. H. Nidditch(Oxford: Oxford University Press, 1978).
- Citations from Hume’s An Enquiry concerning HumanUnderstanding (abbreviated as EHU) are from the Tom L. Beauchampedition (New York: Oxford University Press, 1999), and thus includesection and paragraph numbers; we also add the corresponding pagenumbers in Enquiries concerning Human Understanding and concerningthe Principles of Morals, edited by L. A. Selby-Bigge, thirdedition (abbreviated as SBN), with revised text and notes by P. H.Nidditch (Oxford: Oxford University Press, 1975).
- Citations from Hume’s The History of England(abbreviated as HE, and cited by volume and page numbers) are from thereprint of the final edition of 1778, containing the author’slast corrections and improvements (Indianapolis: Liberty Classics,1983).
Locke
- Citations from Locke’s An Essay concerning HumanUnderstanding are from the Peter H. Nidditch edition (Oxford:Oxford University Press, 1975), and include the Roman numerals of thebook and chapter, followed by the Arabic numeral of the section.
Newton
- Citations from Newton’s Principia are to ThePrincipia: Mathematical Principles of Natural Philosophy,translated and edited by I. Bernard Cohen and Anne Whitman, assistedby Julia Budenz (Berkeley and Los Angeles: University of CaliforniaPress, 1999), and are given in the form (Principia, pagenumbers).
- Citations from Newton’s Opticks are to Opticks:or A Treatise of the Reflections, Refractions, Inflections &Colours of Light, based on the fourth edition, London 1730 (NewYork: Dover, 1979), and are given in the form (Opticks, pagenumbers).
Secondary Sources
The relevant secondary literature is vast. We confine ourselves toEnglish-language literature and, more specifically, to the works citedin the text. These works can be consulted, in turn, for extensivereferences to other secondary literature.
- Allison, Henry E., 1983, Kant’s Transcendental Idealism:An Interpretation and Defense, New Haven: Yale UniversityPress.
- –––, 1996, Idealism and Freedom: Essays onKant’s Theoretical and Practical Philosophy, Cambridge:Cambridge University Press. doi:10.1017/CBO9781139172875
- –––, 2004, Kant’s TranscendentalIdealism: An Interpretation and Defense, revised and enlargededition, New Haven: Yale University Press.
- –––, 2008, Custom and Reason in Hume: AKantian Reading of the First Book of the Treatise, Oxford: OxfordUniversity Press. doi:10.1093/acprof:oso/9780199532889.001.0001
- Baier, Annette C., 1991, A Progress of Sentiments,Cambridge, MA: Harvard University Press.
- Barfoot, Michael, 1990, “Hume and the Culture of Science inthe Early Eighteenth Century”, in M. A. Stewart (ed.),Studies in the Philosophy of the Scottish Enlightenment,Oxford: Oxford University Press, pp. 151–190.
- Beauchamp, Tom L. & Alexander Rosenberg, 1981, Hume andthe Problem of Causation, Oxford: Oxford University Press.
- Beck, Lewis White, 1978, “A Prussian Hume and a ScottishKant”, in his Essays on Kant on Hume, New Haven, CT:Yale University Press, pp. 111–129.
- Bird, Graham, 1962, Kant’s Theory of Knowledge: AnOutline of One Central Argument in the “Critique of PureReason”, New York: Humanities Press.
- Buchdahl, Gerd, 1969, Metaphysics and the Philosophy ofScience, Oxford: Basil Blackwell.
- –––, 1972 [1974], “The Conception ofLawlikeness in Kant’s Philosophy of Science”, inProceedings of the Third International Kant Congress, LewisWhite Beck (ed.), Dordrecht: Springer Netherlands, 4: 149–171.Reprinted in Kant’s Theory of Knowledge, Lewis WhiteBeck (ed.), Dordrecht: Reidel, 1974, pp. 128–150.doi:10.1007/978-94-010-3099-1_9 doi:10.1007/978-94-010-2294-1_14
- Cohen, I. Bernard, 1999, “A Guide to Newton’sPrincipia”, in I. Bernard Cohen and Anne Whitman(trans.), The Principia: Mathematical Principles of NaturalPhilosophy by Isaac Newton, Berkeley, CA: University ofCalifornia Press, pp. 1–370.
- De Pierris, Graciela, 2001, “Hume’s PyrrhonianSkepticism and the Belief in Causal Laws”, Journal of theHistory of Philosophy, 39(3): 351–383.doi:10.1353/hph.2003.0121
- –––, 2002, “Causation as a PhilosophicalRelation in Hume”, Philosophy and PhenomenologicalResearch, 64(3): 499–545.doi:10.1111/j.1933-1592.2002.tb00159.x
- –––, 2006, “Hume and Locke on ScientificMethodology: The Newtonian Legacy”, Hume Studies,32(2): 277–329. [De Pierris 2006 available online (PDF)]
- –––, 2015, Ideas, Evidence, and Method:Hume’s Skepticism and Naturalism concerning Knowledge andCausation, Oxford: Oxford University Press.doi:10.1093/acprof:oso/9780198716785.001.0001
- Fogelin, Robert J., 1985, Hume’s Skepticism in theTreatise of Human Nature, London: Routledge & KeganPaul.
- Friedman, Michael, 1992a, “Causal Laws and the Foundationsof Natural Science”, in Paul Guyer (ed.), The CambridgeCompanion to Kant, Cambridge: Cambridge University Press, pp.161–199. doi:10.1017/CCOL0521365872.006
- –––, 1992b, Kant and the ExactSciences, Cambridge, MA: Harvard University Press.
- –––, 2012, “The Prolegomena andNatural Science”, in Holger Lyre and Oliver Schliemann (eds),Kant: Prolegomena. Ein kooperativer Kommentar, Frankfurt:Klostermann, pp. 299–326.
- –––, 2013, Kant’s Construction ofNature: A Reading of the Metaphysical Foundations of NaturalScience, Cambridge: Cambridge University Press.doi:10.1017/CBO9781139014083
- –––, 2017, “Kant’s Conception ofCausal Necessity and Its Legacy”, in Michela Massimi and AngelaBreitenbach (eds), Kant and the Laws of Nature, Cambridge:Cambridge University Press, pp. 195–213.doi:10.1017/9781316389645.011
- Garrett, Don, 1997, Cognition and Commitment in Hume’sPhilosophy, Oxford: Oxford University Press.
- Guyer, Paul, 1987, Kant and the Claims of Knowledge,Cambridge: Cambridge University Press.doi:10.1017/CBO9780511624766
- –––, 2005, Kant’s System of Nature andFreedom: Selected Essays, Oxford: Oxford University Press.doi:10.1093/acprof:oso/9780199273461.001.0001
- –––, 2008, Knowledge, Reason, and Taste:Kant’s Response to Hume, Princeton: Princeton UniversityPress.
- Kemp Smith, Norman, 1941, The Philosophy of David Hume: ACritical Study of Its Origins and Central Doctrines, London:MacMillan.
- Koyré, Alexandre, 1965, Newtonian Studies, London:Chapman and Hall.
- Kuhn, Thomas S., 1957, The Copernican Revolution: PlanetaryAstronomy and the Development of Western Thought, New York:Random House.
- Laywine, Alison, 1993, Kant’s Early Metaphysics and theOrigins of the Critical Philosophy, Atascadero, Ca.:Ridgeview.
- Melnick, Arthur, 1973, Kant’s Analogies ofExperience, Chicago: University of Chicago Press.
- Owen, David, 1999, Hume’s Reason, Oxford: OxfordUniversity Press. doi:10.1093/0199252602.001.0001
- Paton, H. J., 1936, Kant’s Metaphysic of Experience: ACommentary on the First Half of the Kritik Der Reinen Vernunft, 2vols., London: Allen & Unwin.
- Stein, Howard, 1967, “Newtonian Space-Time”, TexasQuarterly, 10: 174–200.
- Strawson, Galen, 1989, The Secret Connexion: Causation,Realism, and David Hume, Oxford: Clarendon Press.doi:10.1093/acprof:oso/9780199605842.001.0001
- Stroud, Barry, 1977, Hume, London: Routledge & KeganPaul.
- Van Cleve, James, 1973, “Four Recent Interpretations ofKant’s Second Analogy”, Kant-Studien, 64:69–87.
- Watkins, Eric, 2005, Kant and the Metaphysics ofCausality, Cambridge: Cambridge University Press.doi:10.1017/CBO9780511614217
- Wolff, Robert Paul, 1960, “Kant’s Debt to Hume viaBeattie”, Journal of the History of Ideas, 21(1):117–123. doi:10.2307/2708003
- –––, 1963, Kant’s Theory of MentalActivity: A Commentary on the Transcendental Analytic of the Critiqueof Pure Reason, Cambridge, MA: Harvard University Press.
- Wright, John P., 1983, The Sceptical Realism of DavidHume, Manchester, Lancashire: Manchester University Press.
Academic Tools
How to cite this entry. |
Preview the PDF version of this entry at the Friends of the SEP Society. |
Look up this entry topic at the Indiana Philosophy Ontology Project (InPhO). |
Enhanced bibliography for this entryat PhilPapers, with links to its database. |
Other Internet Resources
[Please contact the author with suggestions.]
Related Entries
causation: the metaphysics of | Hume, David | Hume, David: Newtonianism and Anti-Newtonianism | Kant, Immanuel | Kant, Immanuel: critique of metaphysics | laws of nature | Newton, Isaac: Philosophiae Naturalis Principia Mathematica | Newton, Isaac: views on space, time, and motion