1. See Burrows, A., “Dividing the Law of Obligations” in , A., ed., Understanding the Law of Obligations (Oxford: Hart Publishing, 1998) 1 at 8–14Google Scholar.

2. Thus Hume referred to promising as ‘one of the most mysterious and incomprehensible operations that can possibly be imagin’d.’ Hume, D., A Treatise of Human Nature in D. Norton & M. Norton, eds., (Oxford: Oxford University Press, 2000) at 336Google Scholar.

3. Hume was the first to make this observation: ‘Morality is supposed to consist in relation. Every new imposition of morality, therefore, must arise from some new relation of objects; and consequently the will could not produce immediately any change in the morals, but could have that effect only by producing a change upon the objects.’ Ibid. at 332 n. I. Emphasis in original. A physical analogy may clarify Hume’s point. By moving my rook in front of your king, I do not immediately create the physical relationship of proximity that then exists; I merely create the situation in virtue of which that relationship may be said to exist. Analogously, by saying my wedding vows in front of a judge and several witnesses, I directly give rise not to a legal relation between spouses, but rather to a situation in virtue of which that relation may be said to exist.

4. This observation, too, was first made by Hume. Michael Robins provides a contemporary restatement: ‘Stated loosely in the idiom of action theory, “creating an obligation” must be the name of an intentional non-basic act (i.e., roughly something we do by doing something else), and not an intentional basic action with a foreseeable but unintended side-effect.’ M. Robins, Promising, Intending, and Moral Autonomy (Cambridge: Cambridge University Press, 1984) at 6–7. See also H.A. Prichard, “The Obligation to Keep a Promise” in his Moral Obligation: Essays and Lectures (New York: Oxford University Press, 1968) 169 at 170.

5. Among those who adopt this or similar definitions of promise are David Hume, Joseph Raz, John Finnis, John Rawls, John Searle, H.L.A. Hart, Charles Fried, Elizabeth Anscornbe, Richard Bronaugh, and Tony Honoré. See D. Hume, supra note 2, Book III, Section V; J. Raz, “Voluntary Obligations and Normative Powers II” (1972) 46 Proc. Aristotelian Soc. 79; J. Raz, “Promises and Obligations” in P.M.S. Hacker & J. Raz, eds., Law, Morality and Society: Essays in Honour of H. L. A. Hart (Oxford: Clarendon, 1977) 210; J. Finnis, Natural Law and Natural Rights (Oxford: Clarendon Press, 1980) at 298–308; J. Rawls, “Two Concepts of Rules” (1955) 64 Phil. Rev. 3; J. Rawls, A Theory of Justice (Cambridge, MA: Harvard University Press, 1971) at 342–50; J. Searle, Speech Acts: An Essay in the Philosophy of Language (New York: Cambridge University Press, 1969) at 57–64; H.L.A. Hart, “Legal and Moral Obligation” in A.I. Melden, ed., Essays in Moral Philosophy (Seattle, WA: University of Washington Press, 1958) 82 at 100–03; C. Fried, Contract as Promise (Cambridge, MA: Harvard University Press, 1981); G.E.M. Anscornbe, “Rules, Rights, and Promises” (1978) 3 Midwest Studies in Phil. 318; R. Bronaugh, “Promises” in L. Becker, ed., Encyclopedia of Ethics (New York: Garland Press, 1992) 1020; T. Honoré, Responsibility and Fault (Oxford: Hart Publishing, 1999) at 59.

6. This point is eloquently expressed by Elizabeth Anscornbe, ibid. at 319.

7. T.M. Scanlon, “Promises and Practices” (1990) 19 Phil. & Publ. Affairs 199. A revised version of this paper appears as chapter seven of Scanlon’s book What We Owe to Each Other (Cambridge, MA: Belknap Press, 1998). Unless otherwise noted, all citations will be to this latter version.

8. A perlocutionary act is one that can only be successfully executed by means of an utterance if that utterance succeeds in inducing certain (‘perlocutionary’) effects in the hearer, such as an expectation or action in reliance. (Examples include convincing, frightening, deceiving, and assuring.) These are to be distinguished from illocutionary acts, which are performed in rather than by an utterance. (Examples include congratulating, apologizing, reporting, thanking, and warning.) Virtually everyone agrees that promising is an illocutionary act. Theorists differ about whether the act of undertaking a promissory obligation is illocutionary. That is, they differ as to whether the obligation of a promise depends essentially on a perlocutionary intention on the part of the promisor. Those theories I dub ‘perlocutionary’ insist on this dependence. See generally J.L. Austin, How to Do Things With Words (Cambridge, MA: Harvard University Press, 1975) at 101–32.

9. On contract-making as the exercise of a normative power, see: C Fried, supra note 5; H.L.A. Hart, The Concept of Law (Oxford: Clarendon Press, 1984) 27 at 42–43; H.L.A. Hart, supra note 5 at 84–94; L. Fuller, “Consideration and Form” (1941) 41 Colum. L.R. 798 at 806–08; J. Raz “Promises in Morality and Law” (1982) 95 Harvard L.R. 916 at 933–38; B. Coote, “The Essence of Contract” (1988) 1 J. Contract L. 91 at 194–95; M. Ferson, “The Formation of Simple Contracts” (1924) 9 Cornell L. Q. 402; E.A. Farnsworth, Changing Your Mind: The Law of Regretted Decisions (New Haven, CT: Yale University Press, 1998) 9–17, 36–38; R. Barnett, “A Consent Theory of Contract” (1986) 86 Colum. L.R. 269 at 296–300.

10. D. Patterson, “The Value of a Promise” (1992) 11 L. & Phil. 385. Gillian Hadfield comments briefly on Scanlon’s paper in her “Of Sovereignty and Contract: Damages for Breach of Contract by Government” (1997) 8 S. Cal. Interdis. L.J. 467 at 501–04.

11. W.D. Ross put the classic objection: ‘Suppose … that the fulfilment of a promise to A would produce 1,000 units of good for him, but that by doing some other act I could produce 1,001 units of good for B, to whom I have made no promise, the other consequences of the two acts being of equal value; should we really think it self-evident that it was our duty to do the second act and not the first? I think not. We should, I fancy, hold that only a much greater disparity of value between the total consequences would justify us in failing to discharge our prima facie duty to A.’ The Right and the Good (Indianapolis, IN: Hackett Publishing, 1988) at 34–35.

12. J. Narveson, “Promising, Expecting, and Utility” (1971) 1 Can. J. Phil. 207 at 214. Similar views have been espoused by Pall Ardal and, classically, by J.S. Mill, Adam Smith, and Henry Sidgwick. ‘How is a situation altered when a normal, ordinary promise has been made? The promisee expects a certain thing from the promiser. He can thus be disappointed and also not get what he was promised.’ P. Ardal, “And That’s a Promise” (1968) 18 Phil. Q. 225 at 234. “When a person, either by express promise or by conduct, has encouraged another to rely upon his continuing to act in a certain way—to build expectations and calculations, and stake any part of his plan of life upon that supposition, a new series of moral obligations arises on his part towards that person, which may possibly be overruled, but can not be ignored.’ Mill, J.S., On Liberty, D. Spitz, ed., (New York: W.W. Norton, 1975) 94.Google Scholar See also Meek, R., Raphael, D., Stein, P., eds., Adam Smith: Lectures on Jurisprudence (New York: Clarendon Press, 1978) at 92Google Scholar, 87–89; and H. Sidgwick, Methods of Ethics (London: Macmillan & Co, 1874) at 277–88.

13. For a much-discussed criticism of utilitarian theories of promise, see D.H. Hodgson, The Consequences of Utilitarianism: A Study in Normative Ethics and Legal Theory (Oxford: Clarendon Press, 1967) at 40–42. The force of Hodgson’s argument is doubted by Jan Narveson, ibid. at 220–28, and Narveson’s criticism is countered by Michael Robins, “The Primacy of Promising” (1976) 85 Mind 321 at 324–25. Doubts of a different kind are expressed by J.L. Mackie, “The Disutility of Act-Utilitarianism,” in Persons and Values (Oxford: Clarendon Press, 1985) 91; and P. Singer, “Is Act-Utilitarianism Self-Defeating?” (1972) 81 Phil. Rev. 94. See also J. Harsanyi, “Does Reason Tell Us What Moral Code to Follow and, Indeed, to Follow Any Moral Code at All?” (1985) 96 Ethics 42 at 44–45; and D. Regan, “On Preferences and Promises: A Response to Harsanyi” (1985) 96 Ethics 56 at 58–64.

14. This objection is famously put by Bernard Williams in Smart, J.J.C. & Williams, B., Utilitarianism For and Against (Cambridge: Cambridge University Press, 1973) at 93–118.Google Scholar

15. “Voluntary Obligations and Normative Powers I” (1972) 46 Proc. Aristotelian Soc. 59 at 70. MacCormick published a revised version of this paper ten years later: “Voluntary Obligations” in Legal Rights and Social Democracy: Essays in Legal and Political Philosophy (Oxford: Clarendon Press, 1982) 190 Google Scholar.

16. For example, suppose you ask me to help you repair your leaky roof next Saturday. I have tickets to a baseball game on Saturday but feel I owe it to you to help out in a pinch. In order to enhance my chances of being able to make the game, I promise to help you with the roof while at the same time letting you know how much I paid for my seats, in the express hope that you will refrain from relying on me and continue to seek other friends to take my place on Saturday.

17. ‘The expectation created by a promise … is normative; some expectations, for example that the sun will rise on the morrow, are not.’ S. Turner, “Making Normative Soup with Non-Normative Bones” in Sica, A, ed., What is Social Theory? The Philosophical Debates(Oxford: Blackwell, 1998) 118 at 119Google Scholar. See also G. Cupit, “How Requests (and Promises) Create Obligations” (1994) 44 Phil. Q. 439 at 442; and J. Köndgen, “Reconstructing Promissory Obligation: A Socio-Legal Analysis” (1992) 11 Tel Aviv University Studies in Law 151 at 159.

18. In other words, the expectations that attend promises presuppose ‘the more primitive concept of commitment they are supposed to explain.’ M.H. Robins, supra note 4 at 133. See also H.A. Prichard, supra note 4 at 170–71; and G.J. Warnock, The Object of Morality (London: Methuen &Co, 1971) at 98–101.

19. Scanlon, supra note 7 at 296 note 2.

20. Ibid. at 296.

21. The Principle of Fidelity is set out in full below. See text accompanying infra note 37.

22. Scanlon, supra note 7 at 153. See also T.M. Scanlon, “Contractualism and Utilitarianism” in A. Sen & B. Williams, eds., Utilitarianism and Beyond (Cambridge: Cambridge University Press, 1982) 103. It was in this article that Scanlon first formulated his brand of contractualism.

23. Ibid. at 304.

24. Ibid. at 303.

25. Ibid. at 302–03.

26. Scanlon could have done better than to invoke this particular example to illustrate his point that fidelity is a reasonable demand to make of a promisor in certain instances. Our sense that Harold has reason to want the acquaintance to do as he assured him he would is overwhelmed by our sense that he has reason to want the acquaintance not to gratuitously humiliate him, regardless of any assurance.

27. Sam Stoljar makes a similar point in the contractual context. ‘The whole point of recognising an expectation [as enforceable) is to enable the promisee to wait for the performance of a promise without having to “act on it” (such as starting his own performance or incurring expenses in preparation of the exchange), for the simple reason that in many situations the promisee cannot so rely, actively rely, on the other’s promise; all he can do is wait.’ “Promise, Expectation and Agreement” (1988) 47 Cambridge L.J. 193 at 211.

28. Scanlon uses this phrase in his original piece, but abandons it in the revised version. See his “Promises and Practices” supra note 7 at 206.

29. Scanlon, supra note 7 at 303.

30. M. Cohen, “The Basis of Contract” (1933) 46 Harv. L.R. 553 at 573.

31. D. Patterson, supra note 10.

32. Ibid. at 400.

33. Ibid. at 386.

34. Ibid. at 398.

35. Scanlon, supra note 7 at 303–04.

36. Patterson, supra note 10 at 396–98.

37. Scanlon, supra note 7 at 304.

38. ‘No one could reasonably object to a principle that, when these conditions are fulfilled, imposes a duty to provide a warning at the time of creating the expectation if one does not intend to be bound – a duty to say, “This is my present intention, but of course I may change my mind,”or to make this clear in some other way if it is not already clear in the context. Since the burden of such a duty to warn is so slight, and the advantages of being able to enter into binding obligations are significant, one can hardly complain if failure to give such a warning under these conditions leaves one open to the more stringent duty to perform or seek permission to substitute.’ Ibid. at 304–05.

39. Ibid. at 306.

40. I might for example convince you I am a devoted member of a religious sect and then proceed to swear on my honour as a member of that sect that I will perform. Or I might convince you that I will perform because it is in my economic interest to do so. Scanlon supplies some other examples, ibid. at 297–98.

41. ‘When a man says he promises any thing he, … by making use of this form of words, subjects himself to the penalty of never being trusted again in case of failure.’ Hume, supra note 2 at 335. Emphasis in original.

42. For an example of an argument along these lines, see C. McMahon, “Promising and Coordination” (1989) 26 Am. Phil. Q. 239. But cf. G. Den Hartogh, “A Conventionalist Theory of Obligation” (1998) 17 Law & Phil. 351 at 355–56.

43. Scanlon, supra note 7 at 306–07.

44. See text accompanying supra note 38 and see also ibid. at 403, n. 6.

45. Ibid. at 308–09.

46. Ibid. at 298.

47. Robins, supra note 13 at 325. Emphasis in original.

48. Hartogh, supra note 42 at 369.