¹ St Augustine's most complete discussions of lying are to be found in Lying (De mendacio), trans. Mary Sarah Muldowney, and Against Lying (Contra mendaciuni), trans. Jaffee, Harold, in Treatises on Various Subjects, ed. Deferrari, R. J., in Fathers of the Church, vol. 16 (New York: Fathers of the Church, 1952), pp. 53–110Google Scholar and pp. 111-79.

² St. Thomas Aquinas's discussion of truth, lying, deception, hypocrisy and boasting can be found in Summa Theologiae, II/II, 110–12, trans. O'Brien, T. C. (London: Blackfriars, 1972), pp. 133–91Google Scholar.

³ Kant's most forthright defence of the position that it is never morally permissible to tell a lie is to be found in his On a Supposed Right to Lie from Philanthropy, published in 1797. In this essay Kant is only concerned to argue that all lying violates a duty of right. He does add in a footnote, however, that all lying also violates a duty of virtue (to oneself):

I here prefer not to sharpen this principle to the point of saying: 'Untruthfulness is a violation of a duty to oneself.' For this belongs to ethics, but what is under discussion here is a duty of right. The doctrine of virtue looks, in this transgression, only to worthlessness, reproach for which the liar draws upon himself. (RL, 8: 426 n. 1 (p. 612 n. 1))

Kant's argument that all lying violates a duty of virtue is to be found in his discussion of lying in the Doctrine of Virtue, part II of the Metaphysics of Morals (MM, 6: 429–31 (pp. 552-4)). I am not concerned, in this article, with the arguments given by Kant both in his ethics and his philosophy of right as to why it is never morally permissible to tell a lie.

⁴ See, for example, Paton, H. J., ‘An alleged right to lie. A problem in Kantian ethics’, Kant-Studien, 45 (1954), 190–203CrossRefGoogle Scholar ; Ebbinghaus, Julius, ‘Kants Ableitung des Verbotes der Luge aus dem Rechte der Menschheit’, Revue Internationale de Philosophie, 8 (1954), 409–22Google Scholar ; Singer, Marcus George, Generalization in Ethics (New York: Alfred Knopf, 1961), pp. 119–133Google Scholar ; Gregor, Mary J., Laws of Freedom (Oxford: Basil Blackwell, 1963), pp. 126Google ScholarSchwartz, Wolfgang, ‘Kant's refutation of charitable lies’, Ethics, 81 (1970), pp. 62–7CrossRefGoogle Scholar ; Hofmeister, Heimo E. M., ‘The ethical problem of the lie in Kant’, Kant-Studien, 63 (1972), 353–68CrossRefGoogle Scholar ; Hofmeister, Heimo E. M., ‘Truth and truthfulness: a reply to Dr Schwarz’, Ethics, 82 (1972), pp. 262–7Google Scholar ; Wood, Allen W., ‘Kant on false promises’, in Beck, L. W. (ed.), Proceedings of the Third International Kant Congress (Dordrecht: D. Reidel, 1972), pp. 614–19CrossRefGoogle Scholar ; Schwarz, Wolfgang, ‘Truth and truthfulness: a rejoinder’, Ethics, 83 (1973), 173–5CrossRefGoogle Scholar ; Wagner, Hans, ‘Kant gegen “ein vermeintes Recht, aus Menschenliebe zu lugen”’, Kant-Studien, 69 (1978), 91–6Google Scholar ; Fried, Charles, Right and Wrong (Cambridge, MA: Harvard University Press, 1978), pp. 54–78CrossRefGoogle Scholar ; Benton, Robert J., ‘Political expediency and lying: Kant vs. Benjamin Constant’, Journal of the History of Ideas 43 (1982), pp. 135–44CrossRefGoogle Scholar ; Vuillemin, Jules, ‘On Lying: Kant and Benjamin Constant’, Kant-Studien, 73 (1982), 413–24CrossRefGoogle Scholar ; Korsgaard, Christine M., ‘The right to lie: Kant on dealing with evil’, Philosophy and Public Affairs, 15 (1986), 325–49Google Scholar ; Atwell, John E., Ends and Principles in Kant's Moral Thought (Dordrecht: Martinus Nijhoff, 1986), pp. 193–202CrossRefGoogle Scholar ; Geismann, Georg and Oberer, Hariolf (eds), Kant und das Recht der Luge (Wurzburg: Konigshausen &c Neumann, 1986)Google Scholar ; Geismann, Georg, ‘Versuch iiber Kants rechtliches Verbot der Luge’, in Oberer, Hariolf and Seel, Gerhard (eds), Kant: Analysen – Probleme –Kritik (Wurzburg: Konigshausen & Newmann, 1988), pp. 293–316Google Scholar ; Sullivan, Roger J., Immanuel Kant's Moral Theory (Cambridge: Cambridge University Press, 1989), pp. 170–7CrossRefGoogle Scholar ; Sedgwick, Sally, ‘On lying and the role of content in Kant's ethics’, Kant-Studien, 82 (1991), 42–62CrossRefGoogle Scholar ; Atkinson, R. F., ‘Kant's moral and political rigorism’, in Williams, H. L. (ed.), Essays on Kant's Political Philosophy (Chicago: University of Chicago Press, 1992), pp. 228–48Google Scholar ; Maclntyre, Alasdair, ‘Truthfulness, lies, and moral philosophers: what can we learn from Mill and Kant?’, in Peterson, Grethe B. (ed.), The Tanner Lectures on Human Values, vol. 16 (Salt Lake City: University of Utah Press, 1995), pp. 307–61Google Scholar ; Munzel, G. Felicitas, Kant's Conception of Moral Character (Chicago: University of Chicago Press, 1999), pp. 236–53Google Scholar.

⁵ All of Kant's lectures on ethics are based on the ethics textbooks of Alexander Gottlieb Baumgarten. The textbooks used by Kant were the 3rd edition of Baumgarten's Introduction to Practical First Philosophy (Initia philosophiae practicae pritnae) (1760), and the 1st and 2nd editions of his Philosophical Ethics (Ethica philosophica) (1751 and 1763, respectively) (see J. B. Schneewind's Introduction to the Lectures on Ethics, pp. xiii-xxvii). Since Kant was not necessarily advancing his own views in these lectures, what he says in these lectures cannot simply be assumed to be Kant's own position. Nevertheless, throughout this article I shall take in consideration what Kant says in these lectures, wherever possible supporting what he says in the lectures with what he says in his published writings, in order to determine as completely as possible Kant's position on what constitutes a lie and on how lying is to be differentiated from non-mendacious linguistic deception.

⁶ Chisholm, Roderick M. and Feehan, Thomas D., ‘The intent to deceive’, Journal of Philosophy, 74 (1977), 149.CrossRefGoogle Scholar

⁷ Siegler, Frederick A., ‘Lying’, American Philosophical Quarterly, 3 (1966), 128.Google Scholar

⁸ This is my own wording of the necessary conditions for an assertion provided by Newey, Glen in ‘Political lying: a defense’, Public Affairs Quarterly, 11 (1997), 93–116Google Scholar . See esp. pp. 94-102.

⁹ Charles Fried argues in a similar vein concerning an assertion that ‘An assertion may be seen as a kind of very general promise; it is a promise or assurance that the statement is true’ ( , FriedRight and Wrong, pp. 56–7)Google Scholar . Consciously or unconsciously, Fried is echoing W. D. Ross's claim that every time a person makes an assertion she makes an implicit promise to be truthful, and that every lie is a breach of promise and hence a violation of a duty of fidelity:

Some duties rest on previous acts of my own. These duties seem to include…those resting on a promise or what may fairly be called an implicit promise, such as the implicit undertaking not to tell lies which seems to be implied in the act of entering into a conversation (at any rate by civilized men), or of writing books that purport to be history and not fiction. These may be called duties of fidelity. The Right and the Good (Oxford: Oxford University Press, 1930), p. 21)Google Scholar

As Marcus George Singer has argued, however, such a position pushes the problem back to the question whether it is always wrong to break a promise, and this is even less plausible than the proposition about lying [i.e. that it is always wrong to lie], since, while one truth cannot conflict with another (though two honest assertions can), one promise can conflict with another, in the sense that one cannot keep both, or keep one without breaking the other.’ ( , SingerGeneralization, p. 125)Google Scholar

¹⁰ Each of these statements does have a truth-value if the statement is redescribed as a statement about the person's belief. For example, ‘I believe that Al Gore will win the election next year’ is a statement that has a truth-value. The statement is true if I have this belief, and false if I do not.

¹¹ In the Critique of Practical Reason Kant states this principle as follows: ‘[O]ne can do it [what the moral law prescribes] because our own reason recognizes this as its command and says that one ought to do it’ (CPR, 5: 159 (p. 267)).

¹² 'Truth means for Kant the agreement between facts and the propositions about them. The agreement between these is established through a logical judgment. Now it is Kant's opinion that nobody is ever able to guarantee that what he asserts is actually in agreement with the facts. The possibility of error cannot be excluded, since the proposition and the facts are not immediately related to one another but are related by the means of a judgment. Does it not seem absurd to require that someone always tell the truth, knowing that there is no chance that he always knows the truth?’ ( , Hofmeister ‘Truth and truthfulness’, pp. 263–4)Google Scholar

¹³ The duty to be truthful in Aquinas's moral philosophy appears to be the duty to refrain from making statements that are untruthful – to refrain from making statements that do not correspond to what one believes to be true. Aquinas distinguishes between the intention that ‘something false be expressed’ ( , AquinasSumnta Theologicae, p. 149Google Scholar ) and the intention that ‘someone be deceived’ (ibid., p. 151), and argues that the former intention is sufficient for lying: ‘As to the intent to introduce falsity into another's mind by deceiving him, this does not enter into the very species of lying, but is a kind of finishing touch’ (ibid., p. 151). Aquinas holds that a boast ‘is a type of lie’ (ibid., p. 189), and that a ‘humorous lie told to entertain’ (ibid., p. 155) is a lie, and that both violate the duty of truthfulness and are morally impermissible.

¹⁴ Frankfurt, Harry G., ‘The faintest passion’, Proceedings and Addresses of the American Philosophical Association, 66/3 (1992), 5.CrossRefGoogle Scholar

¹⁵ In Religion within the Boundaries of Mere Reason, Kant states that the logical or contradictory opposite of goodness is non-goodness, rather then evil. Presumably this is because there is no middle ground between goodness and lack of goodness, whereas there is a middle ground between good and evil: ‘If the good = a, the opposite contradicting it is the not-good. Now, this not-good is the consequence either of the mere lack of a ground of the good, = 0, or of a positive ground antagonistic to the good, = - a; in this latter case, the not-good can also be called positive evil’ (R, 6: 22 n. 1 (p. 72 n. 1)). In the Doctrine of Virtue, Kant states that the logical or contradictory opposite of virtue is lack of virtue, rather than vice, again presumably because there is no middle-ground between virtue and lack of virtue, whereas there is a middle ground between virtue and vice: ‘Virtue – + a is opposed to negative lack of virtue (moral weakness = 0) as its logical opposite (contradictorie oppositum); but it is opposed to vice = - a as its real opposite (contrarie s. realiter oppositum)’ (MM, 6: 384 (p. 516)). Here I have corrected this edition of the Gregor translation, which reads ‘vice = + a’.

¹⁶ For a discussion of the origin and authenticity of the Education see Louden, Robert B., Kant's Impure Ethics (Oxford: Oxford University Press, 2000), pp. 33–6Google Scholar . I agree with Louden that, although the work is probably a compendium of different lectures and lecture materials, it is all Kant's own work.

¹⁷ This was not an idle question for Kant. The dedication to the 1st edition of the Critique of Pure Reason, for example, reads ‘Your Excellency's humble, most obedient servant’ (CPUR, A vi (p. 95)).

¹⁸ Kant is here contrasting a lie in the sense of ethics with a lie in the sense of the philosophy of right, since he has already said that ‘In the doctrine of right an intentional untruth is called a lie only if it violates another's right; but in ethics, where no authorization is derived from harmlessness, it is clear enough that no intentional untruth in the expression of one's thoughts can refuse this harsh name’ (MM, 6: 429 (p. 552)).

¹⁹ On the distinction between intention and motive, see, for example, John Stuart Mill: ‘The morality of the action depends entirely on the intention – that is, upon what the agent wills to do. But the motive, that is, the feeling which makes him will so to do, when it makes no difference in the act, makes none in the morality’ (Utilitarianism, ed. Crisp, Roger (Oxford: Oxford University Press, 1998), p. 65)Google Scholar.

²⁰ Kant says ‘usually’ here because he wishes t o distinguish between a lie ‘in the sense bearing upon rights’ (MM, 6: 238 n. 1 (p. 394 n. 1)), which violates a duty of right, and a lie in the sense of ethics, which violates a duty of virtue (see n. 18 above). There is no indication that he does not also consider such a lie to violate a duty of virtue, and to be a lie in the sense of ethics.

²¹ Isenberg, Arnold, ‘Deontology and the ethics of lying’, Philosophy and Phenomenological Research, 24 (1964), 473.CrossRefGoogle Scholar

²² Kant does not say whether the servant should also be held legally responsible for the crime of his master. However, on the basis of the argument provided in the Right to Lie, according to which a person is legally responsible for all of the harmful consequences of her lie, it can be concluded that a servant who lies to a guard sent to arrest his master, thereby unwittingly enabling his master to commit a crime, should also be held legally responsible for the crime of his master.

²³ Such a lie is described in Jean-Paul Sartre's short story, ‘Le Mur’, in he Mur (Paris: Gallimard, 1939), pp. 9–34Google Scholar.

²⁴ Raphael Demos argues that it is an ‘odd consequence’ that in ‘In ordinary language … I have lied to you although you have not believed me and so have not been misled by me’ ('Lying to oneself, journal of Philosophy, 57 (1960), 588)CrossRefGoogle Scholar . In order to ‘avoid this oddity’, he defines a lie as follows: ‘I will say that ‘B lies to (deceives) C means: B intends to induce a mistake belief in C., B succeeds in carrying out this intention, and finally B knows (and believes) that what he tells C is false.’ (ibid., p. 588) According to this definition, the person at the door in Kant's example does not lie to the would-be murderer. Siegler considers the same problem, and in order to 130 solve it, proposes to distinguish between ‘lying’ and ‘telling a lie': ‘the falsity of what is said is perhaps a necessary condition for telling a lie but not for lying’ ( , Siegler ‘Lying’, p. 131)Google Scholar . On this account, the person at the door in Kant's example lies, but does not tell a lie.

²⁵ Mannion, D. S., ‘Lying and lies’, Australasian Journal of Philosophy, 47 (1969), 135.Google Scholar

²⁶ It should be noted that many philosophers reject the possibility of lying to oneself. For example, David Simpson holds that ‘Finally, lying is something that is necessarily done to a subject or subjects other than ourselves, at least, to a consciousness other than our own’ (‘Lying, liars and language’, Philosophy and Phenomenological Research, 52 (1992), 626)Google Scholar . Chisholm and Feehan hold that it is not possible for a person to lie to her ‘present self, but that it is possible for her to lie to her ‘future self: ‘[I]t is difficult to see how, at any time t, a man who believed p not to be true, could assert p to himself with the intention of causing himself, at that time t, to believe p. But he could assert p to himself with the intention of causing himself, at some time later than t, to believe p' ( , Chisholm and , Feehan ‘Intent to deceive’, p. 158)Google Scholar.

²⁷ Insofar as Kant divides the person who lies to herself into the person who tells the lie, on the one hand, and the 'inner judge, who is thought of as another person’, on the other, it may be argued that this is not an instance of a person lying to herself. The first self lies to the second self, and not to herself.

²⁸ As Henry E. Allison has pointed out, it appears that what Kant has in mind here is radical evil:

Although the expression is not used, it seems reasonably clear that what Kant has in mind here is precisely radical evil. The claim that this corrupting evil, manifested in the lie to oneself or self-deception, prepares the ground for deceitful treatment of others and for immorality in general. (Kant's Theory of Freedom (Cambridge: Cambridge University Press, 1990), pp. 271–2)Google Scholar

In various places in his writings, Kant argues that the ‘rotten spot’ of mendacity has its roots in the radical evil of human nature. See, for example, in the Miscarriage, where Kant claims that the ‘principal affliction of human nature’ is the ‘propensity to falsehood’ (M, 8: 267 (p. 34)), which is the propensity to 'mendacity (falsity, even without any intention to harm)’ (M, 8: 270 (p. 36)).

²⁹ Quoted in Cassirer, Ernst, Kant's Life and Thought, trans. Haden, James (New Haven: Yale University Press, 1981, p. 395Google Scholar . In his letter to Moses Mendelssohn on 8 April 1766, Kant says that ‘Losing the self-respect that stems from a sense of honesty would therefore be the greatest evil that could, but most certainly shall not, befall me. Although I am absolutely convinced of many things that I shall never have the courage to say, I shall never say anything I do not believe.’ (C, 10: 69 (pp. 89-90))

³⁰ Baier, Annette, ‘Why honesty is a hard virtue’, in Flanagan, Owen and Rorty, Amelie Oksenberg (eds), Identity, Character, and Morality: Essays in Moral Psychology (Cambridge, MA: MIT Press, 1990), p. 266Google Scholar . Concerning the impossibility of volunteering absolutely everything that a person believes to be true, Mark Kingwell has said:

Although we frequently make a coherent distinction between ‘partial’ and ‘whole’ truth in certain matters (i.e., in condemning lies of omission), the notion of ‘full disclosure’ per se is not meaningful. What, after all, could it mean for me to tell the whole truth? Saying all that I knew? All that I could remember? Or all that was relevant? My suspicion is that we always employ situation-specific guidelines on disclosure, usually concerning relevance. (‘Is it rational to be polite?’, Journal of Philosophy, 90 (1993), 388 n. 1)Google Scholar

³¹ In the Groundwork Kant argues, about telling a lie to obtain money, that ‘I could indeed will the lie, but by no means a universal law to lie’ (G, 4: 403 (p. 57)), for the maxim ‘when I believe myself to be in need of money I shall borrow money and promise to repay it, even though I know that this will never happen’ is such that it ‘could never hold as a universal law of nature and be consistent with itself, but must necessarily contradict itself (G, 4: 422 (p. 74)). It would appear, then, that telling a lie violates a duty of narrow obligation: ‘Some actions are so constituted that their maxim cannot even be thought without contradiction as a universal law of nature … It is easy to see that the first is opposed to strict or narrower (unremitting) duty’ (G, 4: 424 (p. 75)). In the Doctrine of Virtue, however, Kant argues that all duties of virtue are wide duties: ‘Ethical Duties are Duties of Wide Obligation’ MM, 6: 390 (p. 521))Google Scholar, and he argues that lying is a violation of a ‘human being's duty to himself regarded merely as a moral being (the humanity in his own person)’ MM, 6: 429 (p. 552))Google Scholar . It would appear, then, that telling a lie violates a duty of wide obligation. For the purposes of this article I shall assume that telling a lie violates a duty of narrow obligation.

³² As Thomas Hill, Jr. has said, It should be noted, too, that the defect associated with neglect of duties of love is ‘lack of virtue (peccatum),' not negative moral worth or even ‘somewhat bad’ conduct. Virtue, or strength of one's will in following moral principles, is a character trait, not the value of a particular action; and peccatum, despite its original connotations, is Kant's most general term for any transgression, i.e., whatever falls off from what it should be. This includes unintentional wrongs, and even poor judgment in working out the practical problems posed by two conflicting, indefinite principles. (‘Imperfect duty and supererogation’, in Dignity and Practical Reason (Ithaca, NY: Cornell University Press, 1992), p. 174)Google Scholar

³³ Adler, Jonathan E., ‘Lying, deceiving, or falsely implicating’, Journal of Philosophy, 94 (1997), 435–52CrossRefGoogle Scholar . Hereafter referred to as ‘LD’.

³⁴ Kuehn, Manfred, Kant: A Biography (Cambridge: Cambridge University Press, 2001), p. 380.CrossRefGoogle Scholar

³⁵ This does not mean that Kant never told a lie. In the Neue Preussische Provinzialblatter, 1848, no. 14, it is reported about Kant that ‘In his last years his conscience troubled him, because at one time, in order to decline a disagreeable invitation, he pretended to be already invited for the time designated’ (quoted in Stuckenberg, J. H. W., The Life of lmmanuel Kant (2nd edn, Lanham, MD: University Press of America, 1986), p. 446 n. 132)Google Scholar.

³⁶ Corrie ten Boom, with John and Sherrill, Elizabeth, The Hiding Place (New York: Bantam Books, 1971), p. 91Google Scholar . Concerning this case, the author reports herself as exclaiming about her friend's deception ‘[I]t isn't logical to say the truth and do a lie!’ (ibid., p. 91; emphasis in original).

³⁷ , GregorLaws of Freedom, p. xii.Google Scholar

³⁸ Earlier versions of parts of this article were read at the Southeastern Seminar in Early Modern Philosophy at Duke University in October 1999, at Washington and Lee University in January 2000, at the Harvard University/MIT Graduate Philosophy Conference in March 2000, at the University of Pittsburgh/Carnegie Mellon Graduate Philosophy Conference in March 2000, at the Eastern Division Meeting of the American Philosophical Association in New York in December 2000, and at Southern Virginia University in October 2001.1 would like to thank all of those who made comments on those occasions, in particular Tad Schmaltz, Sam Rickless, Doug Jesseph, Don Garrett, Carl Posy, Joel Schickel, Greg Cooper, Harry Pemberton, Lad Sessions, Chuck Boggs, Jack Wilson, Oliver Sensen, Andrew Kuper, Louis-Philippe Hodgson, Marc Schattenmann, Eric Sanday, Arthur Kufflick and John Armstrong. For comments on written drafts, and conversations about the arguments contained in these drafts, I would like to thank Alasdair Maclntyre, Glen Newey, Evelyn Mahon, Joseph Mahon, Katarzyna Wroblewski, Bernard Gert, Chuck Mathewes, Joe Neisser, Anne Margaret Baxley, Jonathan Adler, Ashley Lane, Cara Palazzolo and Howard Williams, as well as three anonymous referees for Kantian Review.