1. Compare Dubber, Markus D., Criminal Law: Model Penal Code (New York: Foundation Press, 2002) at 238—39 Google Scholar. For convenience, I will refer to consent as a “defence” regardless of whether it negates an element of the offence of assault (as in Canadian law) or operates as a justification for conduct that remains assaultive (as suggested by Gardner, John, “Justification Under Authority” (2010) 23 Can. J. L. & Jur. 71 at 76Google Scholar).

2. Kant, Immanuel, The Metaphysics of Morals, trans. by Gregor, M.J. (Cambridge: Cambridge University Press, 1996) at 229—33 and 236-38CrossRefGoogle Scholar) (all page references are to Vol. 6 of the Royal Prussian Academy edition of Kant’s works).

3. Ripstein, Arthur, Force and Freedom (Cambridge, MA: Harvard University Press, 2009) at 125—32 CrossRefGoogle Scholar.

4. See, for example, Lawrence v. Texas, 539 U.S. 558 (2003)Google Scholar, overruling Bowers v. Hardwick, 478 U.S. 186 (1986)Google Scholar.

5. See, for example, Criminal Code, R.S.C. 1985, c. C-46, s. 14 Google Scholar; Stefani, Gaston, Levasseur, Georges, & Bouloc, Bernard, Droit pénal général, 18e éd. (Paris: Dalloz, 2003) at 343.Google Scholar

6. Model Penal Code, §§210.5; Criminal Code, s. 24, supra note 1; Stefani et al., supra note 5 at 123.

7. Model Penal Code, §§2.11(2), supra note 1; R. v. Donovan, [1934] 2 K.B. 498 Google ScholarPubMed (C.A.); R. v. Brown (1993), 97 Cr.App.R. 44 Google Scholar (H.L.); R. v. Jobidon (1991), 66 C.C.C. (3d) 454 Google ScholarPubMed (S.C.C.); Stefani et al., supra note 5 at 343.

8. Feinberg, Joel, Harm to Self (New York: Oxford University Press, 1986) at 120—42 and 344-74Google Scholar.

9. Jobidon, supra note 7 at 491-96.

10. Kant, supra note 2 at 250; Ripstein, supra note 3 at 40-42. Consent and non-consent play no role at all in the definition of many crimes, for example, prostitution and drug trafficking. A Kantian account of these crimes would therefore need to explain why a legal order concerned only with the regulation of the interaction of free and equal persons required or permitted the criminalization of the activity regardless of consent.

11. For a different Kantian account of the same problem, see Baker, Dennis J., “The moral limits of consent as a defence in the criminal law” (2009) 12 New Crim. L. Rev. 93 Google Scholar. Baker derives a limit on consent in criminal law from each individual’s duties of virtue in respect of his or her own person. But Kant would have rejected this explanation because he held that the law could enforce only duties of right, not duties of virtue. (Kant, supra note 2 at 382). In contrast to Baker’s, my account is founded not on Kant’s doctrine of virtue but on Kant’s philosophy of right.

12. For a recent effort to do so, see Ripstein, supra note 3.

13. “A person is a subject whose action can be imputed to him” while “a thing is that to which nothing can be imputed.” Kant, supra note 2 at 223.

14. Compare Ripstein, supra note 3 at 30-42.

15. Compare Kant, supra note 2 at 230.

16. Ibid.

17. For an effort to explain tort law principles in terms of this formal idea of right, see Weinrib, Ernest J., The Idea of Private Law (Cambridge, MA: Harvard University Press, 1995)Google Scholar; for an effort to explain some aspects of criminal law in these terms, see Ripstein, supra note 3 at 300-24.

18. Compare Mulholland, Leslie Arthur, Kant’s System of Rights (New York: Columbia University Press, 1990) at 136—38 Google Scholar; Ripstein, supra note 3 at 107-32.

19. Kant, supra note 2 at 250.

20. Ibid. at 260-89.

21. That is why the third category of acquired rights does not include any property right to others, which cannot exist in Kant’s account, but does include “rights in persons akin to rights in things.” This category of personal status is necessary to explain the structure of familiar legal relationships, for example the parent-child relationship. But some of Kant’s views about precisely what falls into this category seem to violate his own injunction against giving a person a right to possess another person. For example, see his discussion of the master-servant relationship: ibid. at 283-84.

22. Ibid. at 270 [emphasis in original]; see also ibid. at 359.

23. This duty to oneself, like duties to others, does indeed fall under the doctrine of virtue. (Ibid. at 421-28). But under the doctrine of virtue one is required to make the duty the ground of one’s action, whereas under the doctrine of right one’s motive for compliance is irrelevant. Thus a duty of virtue cannot be coercively enforceable, while a duty of right must be capable of coercive enforcement; the external incentive provided by the law can ensure compliance but cannot make the duty of virtue the ground of action. So a puzzle remains about how a duty to oneself can have juridical standing.

24. Ibid. at 236.

25. Kant divides “the system of duties of right into internal duties, external duties, and duties that involve the derivation of the latter from the principle of the former by subsumption.” Ibid. at 237 [emphasis in original].

26. Kant’s conception of one’s duties to oneself is frequently discussed in the literature on the doctrine of virtue. See, among many others, Gregor, Mary, Laws of Freedom (Oxford: Basil Blackwell, 1963) at 101—02 Google Scholar; Sullivan, Roger J., Immanuel Kant’s Moral Theory (Cambridge: Cambridge University Press, 1989) at 186—88 CrossRefGoogle Scholar; Herman, Barbara, The Practice of Moral Judgment (Cambridge, MA: Harvard University Press, 1993) at 113—31 Google Scholar; Korsgaard, Christine, Creating the Kingdom of Ends (Cambridge: Cambridge University Press, 1996) at 87—101 CrossRefGoogle Scholar; Dean, Richard, The Value of Humanity in Kant’s Moral Theory (Oxford: Clarendon Press, 2006) at 125—30 and 217-20CrossRefGoogle Scholar. But, apart from the helpful and suggestive remarks by Gregor, Laws of Freedom at 46-48, by Mulholland, supra note 18 at 161-64, and by Rosen, Allen D., Kant’s Theory of Justice (Ithaca, NY: Cornell University Press, 1993) at 20—26 Google Scholar, there was until recently no good published treatment of the place of a limit on consent in Kant’s doctrine of right. The reason for this lacuna might be the widely-held view that, for Kant, a violation of a duty to oneself “is not a matter for legal concern” ( Hill, Thomas E., Jr., Dignity and Practical Reason in Kant’s Moral Theory (Cambridge: Cambridge University Press, 1992) at 183 Google Scholar); see also Potter, Nelson, “Duties to Oneself, Motivational Internalism, and Self-Deception in Kant’s Ethics” in Timmons, Mark, ed., Kant’s Metaphysics of Morals: Interpretive Essays (Oxford: Oxford University Press, 2002) 371 Google Scholar). But a violation of a duty to oneself is a matter for legal concern where it affects the rightfulness of one’s interaction with others. Ripstein, supra note 3 at 133-43, has recently provided an account of limits on consent that is generally compatible with the account I offer in this paper. However, Ripstein’s account is so abstract that “it provides no particular resolution” of whether, for example, mutilation, tattooing, or ear-piercing can be consented to (at 142). I seek to provide some criteria for deciding these questions.

27. Kant, supra note 2 at 422.

28. Suicide and attempted suicide were crimes at common law, but these offences typically have been abolished either by statute or by the general tendency to abolish common law crimes. See LaFave, Wayne R. & Scott, Austin W., Criminal Law, 2nd ed. (St. Paul, MN: West, 1986) at 649 Google Scholar; Suicide Act 1961, 1961, c. 60. Suicide and attempted suicide are also not offences in the federal jurisdiction in the United States, under the Model Penal Code, supra note 1, or under the law of France (see Stefani et al., supra note 6 at 123). Assisting another to commit suicide remains a separate offence in England (see Suicide Act, s. 2(1)) and Canada (Criminal Code, s. 281), and may amount to murder or manslaughter under other penal codes.

29. Kant, supra note 2 at 277 and 363.

30. Ibid. at 277-80.

31. Ibid. at 238.

32. Sen, Amartya K., “Capability and Well-Being” in The Quality of Life, ed. by Nussbaum, Martha & Sen, Amartya K. (Oxford: Clarendon Press, 1993) 31.Google Scholar

33. Ibid.

34. Ibid. at 47.

35. A surgeon should refuse on ethical grounds to perform an operation the only purpose of which was to remove a healthy appendix because the risks associated with the procedure outweigh its anticipated benefits. But the point I am addressing in this paper is not the ethical boundaries of surgery, but whether the law of assault should refuse to recognize the patient’s consent to a surgeon’s removal of a healthy appendix. It is entirely possible for a procedure to be medically unethical without being criminal. This may be true of much cosmetic surgery.

36. Donovan, supra note at 507; Brown, supra note 7 at 47; R. v. Dica, 2004 EWCA 1103 at paras. 41-46Google Scholar.

37. Model Penal Code, §§2.11(2)(b), supra note 1.

38. Jobidon, supra note 7 at 491-96.

39. Stefani et al., supra note 5 at 343 [my translation].

40. Ibid. at 345-46; see also Pin, Xavier, “Le consentement à la lésion de soi-même en droit pénal. Vers la reconnaissance d’un fait justificatif?” (2009) 49 Droits 83 Google Scholar.

41. “Intentional” infliction here has its usual legal meaning of purposeful or knowing infliction; compare Dubber, supra note 1 at 63-67.

42. Compare Dworkin, Ronald, Life’s Dominion (New York: Vintage, 1994) at 179—241 Google Scholar.

43. “ … in my circuit in anno II. Jacobi regis [1603], in the county of Leicester, one Wright, a young strong and lustie rogue, to make himselfe impotent, thereby to have the more colour to begge or to be relieved without putting himselfe to any labour, caussed his companion to strike off his left hand; and both of them were indited, fined, and ransomed therefore, and that by the opinion of the rest of the justices for the cause aforesaid.” Coke, Edward, A Commentary upon Littleton, 13th ed. (London: Kearsley and Robinson, 1775) at 127 Google Scholar, cited in Jobidon, supra note 7 at 476.

44. Herman, Barbara, “Could It Be Worth Thinking about Kant on Sex and Marriage?” in A Mind of One’s Own: Feminist Essays on Reason and Objectivity, ed. by Antony, L.M. & Witt, C. (Boulder, CO: Westview, 1993) 49.Google Scholar See also Woolley, Alice, “Excluded by Definition: Same-Sex Couples and the Right to Marry” (1995) 45 U.T.L.J. 471 CrossRefGoogle Scholar; Kneller, Jane, “Kant on sex and marriage right” in The Cambridge Companion to Kant and Modern Philosophy, ed. by Guyer, Paul (Cambridge: Cambridge University Press, 2006) 447.CrossRefGoogle Scholar

45. Kant, supra note 2 at 277, referring to the “unmentionable vices” of bestiality and homosexuality.

46. Ibid. at 278 [emphasis in original]. The word “enjoyment” here refers to use, not pleasure: cf. Kant, ibid. at 359-60.

47. Ibid. at 359-60 [emphasis in original].

48. Herman, supra note 44 at 61.

49. Ibid. at 61.

50. Ibid. at 62.

51. Ibid. at 63.

52. Ibid. at 63; compare Kneller, supra note 44 at 454-65.

53. Woolley, supra note 44 at 507-13.

54. Kant, supra note 2 at 278.

55. The activities amounted to “genital torture and violence to the buttocks, anus, penis, testicles and nipples”, including branding with a heated wire and piercing with fish-hooks: Brown, supra note 7 at 51.

56. The majority is pretty clearly of the view that sado-masochistic sex causing bodily harm cannot be consented to because it is socially valueless. “Pleasure derived from the infliction of pain is an evil thing.” Ibid. at 52 per Lord Templeman. “Sado-masochistic homosexual activity cannot be regarded as conducive to the enhancement or enjoyment of family life or conducive to the welfare of society … [and] can scarcely be regarded as a ‘manly diversion’ …”. Ibid. at 67 per Lord Lowry.