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On Three Alleged Theories of Rational Behavior


What behavior is rational? It's rational to act ethically, some think. Others endorse instrumentalism – it is rational to pursue one's goals. Still others say that acting rationally always involves promoting one's self-interest. Many philosophers have given each of these answers. But these answers don't really conflict; they aren't vying to describe some shared concept or to solve some mutually acknowledged problem. In so far as this is debated, it is a pseudo-debate. The different uses of ‘rational action’ differ merely in meaning. I shall defend the following claims: ‘rational behavior’ is used in ethical, prudential, and instrumental ways (section I); these uses of ‘rational behavior’ are distinct (section II); they do not represent competing theories of rational behavior (section III); we should stop using ‘rational behavior’ ethically and prudentially, but we may continue its instrumental use (section IV).

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1 For an illuminating discussion of why philosophers overuse ‘rational’, see Jonas Olson, ‘Reasons and the New Non-Naturalism’ (unpublished).

2 Actions can be conceived as resulting from choices, so ‘rational action’ does not always mean ‘rational choice’. But even then, an act is considered rational just in case it is rationally chosen, so action and choice remain closely related.

3 Ordinary speakers use ‘rational behavior’ in other ways. For example, acting rationally is often contrasted with acting from emotion or impulse. Philosophers talk this way too, but the three main uses get more currency.

4 But not always; see Alan Gewirth, ‘Rationality vs. Reasonableness’, Encyclopedia of Ethics, 2nd edn., vol. 3, ed. L. C. Becker and C. B. Becker (New York and London, 2001), pp. 1451–4. Also, Parfit's recent work treats the two terms differently (see D. Parfit, ‘Climbing the Mountain’, unpublished).

5 Rational behavior is less often thought of as behavior permitted by reasons, such that one might be permitted to act with less than full rationality. In general, the literature is about fully, not partly, rational behavior.

6 Gibbard A., Wise Choices, Apt Feelings (Cambridge, Mass., 1990), p. 49.

7 As Brandt says, ‘Sometimes, “it is rational for X to” seems to be identified with “X ought to” . . .’ (Brandt Richard B., ‘The Concept of Rational Action’, Rationality in Action, ed. Moser P. K. (Cambridge, 1990), p. 398). Others might say that the sphere of the rational includes the ethical but is broader. Making a valid deduction, for example, might be considered rational without being thought ethical.

8 According to Sen, ‘there are two predominant methods of defining rationality of behavior in mainline economic theory. One is to see rationality as internal consistency of choice, and the other is to identify rationality with maximization of self-interest’ (Sen A., Ethics & Economics (Oxford, 1987), p. 12).

9 In attributing the ethical view to Sidgwick, I rely on the impressions of Parfit, Frankena and Richardson (Parfit D., Reasons and Persons (Oxford, 1984), p. 129; Frankena William K., ‘Sidgwick and the History of Ethical Dualism’, Essays on Henry Sidgwick, ed. Schultz B. (Cambridge, 1992), pp. 175–98, at p. 194; and Henry S. Richardson, ‘Commensurability as a Prerequisite of Rational Choice’, History of Philosophy Quarterly, 8.2 (April 1991), pp. 181–97, at pp. 186–7). Unfortunately I know of no passage in which Sidgwick obviously uses ‘rational’ interchangeably with ‘ethical’. But Sidgwick does define ‘unreasonable action’ as ‘voluntary action contrary to a man's deliberate judgment as to what is right or best for him to do’ (Sidgwick Henry, ‘Unreasonable Action’, Practical Ethics: A Collection of Addresses and Essays (Oxford, 1998), p. 132). And Sidgwick also calls this phenomenon ‘subjective irrationality’ (p. 134). See Smart J. J. C. (with Bernard Williams), ‘An Outline of a System of Utilitarian Ethics’, Utilitarianism For and Against (Cambridge, 1973), pp. 374, at pp. 46–7; Brandt R., A Theory of the Good and the Right (Oxford, 1979), p. 10 and Brandt, ‘The Concept of Rational Action’, pp. 413–14; W. K. Frankena, Thinking About Morality (Ann Arbor, 1980), p. 85; Hare R. M., Moral Thinking (Oxford, 1981), pp. 104–5 and p. 214; Gauthier David, ‘Deterrence, Maximization, and Rationality’, The Security Gamble, ed. MacLean Douglas (Totowa, 1984), p. 115 and elsewhere; Gibbard as already cited in the text and on p. 49 of Wise Choices; Quinn Warren, Morality and Action (Cambridge, 1993), p. 254 (in Essay 12, ‘Putting Rationality in its Place’); Sumner L. W., ‘Welfare, Preference, and Rationality’, Value, Welfare, and Morality, ed. Frey R. G. and Morris Christopher (Cambridge, 1993), pp. 88–9; Scanlon T. M., What We Owe to Each Other (Cambridge, Mass., 1998), pp. 30–2 (though Scanlon uses ‘rational’ and ‘reasonable’ in various subtly different ways).

10 Hare, Moral Thinking, p. 190. For simplicity, I ignore Frankena's distinction between the rationality of pursuing one's happiness and the rationality of pursuing one's perfection. (See William K. Frankena, ‘Concepts of Rational Action in the History of Ethics’, Social Theory and Practice 9.2–3 (Summer–Fall 1983), pp. 165–97, at p. 168.)

11 For a taste of Sidgwick's view, see The Methods of Ethics, 7th edn. (Indianapolis, 1906; repr. 1981), p. 498. Sidgwick's list of philosophers who sympathize with identifying rational and self-interested action includes the ancients, Spinoza, Hobbes, Cumberland, Shaftesbury, Samuel Clark, Butler, Berkeley, Hume, Kant, Paley, Stewart, Reid, Bentham, and Comte. On close inspection, Shaver disagrees with putting Butler, Hume, Kant, and Bentham on this list but adds John Clark (R. Shaver, Rational egoism (Cambridge, 1999), ch. 4). Sidgwick on ancient Greece: The Methods of Ethics, pp. 91–2; Spinoza: The Methods of Ethics, p. 89; Hobbes: The Methods of Ethics, pp. xix, 86, 89; Cumberland: ‘Hedonism and Ultimate Good’, Mind 2.5 (1877), pp. 27–38, at p. 30; Shaftesbury: Outlines of the History of Ethics, 5th edn. (Indianapolis, 1988, originally 1902), pp. 184–90; Samuel Clark: The Methods of Ethics, pp. 119–20; Butler: The Methods of Ethics, pp. 119–20 and pp. 205–6; Berkeley: The Methods of Ethics p. 120; Hume: Outlines of the History of Ethics, pp. 205–6n.; Kant: Outlines of the History of Ethics, p. 276; Paley: The Methods of Ethics, p. 121; Stewart: Outlines of the History of Ethics, p. 232n. 1; Reid: Outlines of the History of Ethics, p. 228; Bentham: The Methods of Ethics, p. 119; Comte: Outlines of the History of Ethics, pp. 268–9.

12 Henry Sidgwick, ‘Some Fundamental Ethical Controversies’, Mind, 14.56 (1889), pp. 473–87, at p. 483.

13 Parfit, Reasons and Persons, p. 130. This is overstated; see Pettit and Smith's claim below.

14 Sen, Ethics & Economics, p. 15.

15 Gauthier D., Moral Dealing: Contract, Ethics and Reason (Ithaca, NY, 1990), p. 152. But see below: by ‘the maximization of individual utility’ Gauthier might mean, not the maximization of individual welfare, but the maximization of individual preference-satisfaction, which is different.

16 See D. Hume, A Treatise of Human Nature (1739), bk. 2, pt. 3, sect. 3; Ramsey Frank, ‘Truth and Probability’, The Foundations of Mathematics and Others Essays (London, 1931), pp. 156–98; Russell B., Human Society in Ethics and Politics (London, 1954), p. viii; Savage L. J., The Foundations of Statistics (New York, 1954) and The Foundations of Statistics, 2nd edn. (New York, 1972); Hempel C. G., Aspects of Scientific Explanation (New York, 1965), p. 463; Foot Philippa, ‘Morality as a System of Hypothetical Imperatives’, Virtues and Vices and Other Essays in Moral Philosophy (Berkeley, 1978), pp. 157–73, p. 162 (but Foot changed her view; see Natural Goodness (Oxford, 2001)); Williams Bernard, ‘Internal and External Reasons’, Moral Luck (Cambridge, 1981), pp. 101–13; Harsanyi John C., ‘Morality and the Theory of Rational Behavior’, Utilitarianism and Beyond, ed. Sen A. and Williams B. (Cambridge, 1982), pp. 3962, at p. 42; Simon H., Reason in Human Affairs (Stanford, 1983), pp. 78; Harman Gilbert, ‘Human Flourishing, Ethics, and Liberty’, Philosophy and Public Affairs 12 (1983), pp. 307–22, at p. 320; Fumerton R. A., Reason and Morality: A Defense of the Egocentric Perspective (Ithaca, NY, 1990), p. 155; Allingham M., Rational Choice (Basingstoke, 1999), pp. 12.

17 Pettit Philip and Smith Michael, ‘Parfit's P’, Reading Parfit, ed. Dancy Jonathan (Oxford, 1997), pp. 7195, at pp. 83–4.

18 Sobel, however, does talk about this. See J. H. Sobel, Taking Chances (Cambridge, 1994), ch. 10 (originally in Theoria 49 (1983), pp. 159–83), sect. 1.

19 See Audi Robert, ‘Rationality and Valuation’, Rationality in Action, ed. Moser P. K. (Cambridge, 1990), p. 422, and see Quinn, Morality and Action, p. 211 (in Essay 11, ‘Rationality and the Human Good’). On whether instrumentalists should interpret preference in terms of belief, liking or valuing, see David J. Velleman, ‘The Story of Rational Action’, Philosophical Topics 21.1 (Spring 1993), pp. 229–54, at pp. 232–3. See Hampton J. E., The Authority of Reason (Cambridge, 1998), ch. 5, for criticisms of instrumentalist accounts of preference.

20 See, for example, Pettit and Smith, ‘Parfit's P’, p. 79, and Robert Audi, ‘Rationality and Valuation’, p. 418. It is my own assumption that instrumentalists require coherence from beliefs, just as they require coherence from desires.

21 See, for example, Gardenfors Peter and Sahlin Nils-Eric, ‘Introduction: Bayesian Decision Theory – Foundations and Problems’, Decision, Probability and Utility, ed. Gardenfors P. and Sahlin N. (Cambridge, 1988), pp. 115, at p. 4.

22 What should we say if I blindly follow my horoscope, and if, coincidentally, my evidence entails what my horoscope says? We might say that my action is rational, but I am not. Here I follow Pettit Philip and Smith Michael, ‘Practical Unreason’, Mind 102 (1993), p. 58.

23 See, for example, Savage, The Foundations of Statistics, 1st edn., pp. 19–21.

24 See, for example, Sen Amartya, ‘Rationality and Uncertainty’, Recent Developments in the Foundations of Utility and Risk Theory, ed. Daboni L. et al. (Dordrecht, 1986), p. 4.

25 See, for example, Shaw W. H., Contemporary Ethics: Taking Account of Utilitarianism (Oxford, 1999), pp. 52–6.

26 As Parfit notes, aside from desire-fulfillment (or preference-satisfaction) theories of self-interest, there are also hedonistic theories, objective list theories, and hybrid theories. See Appendix I of Reasons and Persons.

27 See Parfit, Reasons and Persons, p. 494.

28 And so Eells should not equate well-informed instrumentalist action with action that ‘is truly, objectively in the agent's best interest to perform’ (Eells E., Rational Decision and Causality (Cambridge, 1982), p. 5).

29 See Gauthier David, ‘Rational Constraint: Some Last Words’, Contractarianism and Rational Choice: Essays on David Gauthier's ‘Morals by Agreement’, ed. Vallentyne P. (Cambridge, 1991), pp. 323–30, at p. 323.

30 Rawls J., A Theory of Justice (Cambridge, Mass., 1971), p. 142.

31 Rawls, A Theory of Justice, p. 143.

32 This idea runs through a lot of work. See, for example, Parfit, Reasons and Persons, pt. 2 and ch. 14 (Parfit never implies that the leading uses of ‘rational action’ reflect substantive disagreement in ‘Climbing the Mountain’, but I did find some passages in the 2006 draft of that book to be puzzling without that background assumption); David O. Brink, ‘Sidgwick's Dualism of Practical Reason’, Australasian Journal of Philosophy 66.3 (1988), pp. 291–307; Baier Kurt, ‘Egoism’, A Companion to Ethics, ed. Singer P. (Oxford, 1991), pp. 197204; Quinn, ‘Rationality and the Human Good’; Shaver, Rational Egoism; and many others.

33 Similarly, Chase Wrenn suggested to me that the different uses of ‘rational behavior’ might reflect competing views about which actions are supported by our best arguments. So, on instrumentalism, we cannot profitably argue about ultimate ends; on the ethical and self-interested accounts, we can, with those accounts disagreeing about which ends our arguments support. However, this can't be what is at issue, since the content of the literature on ultimate ends overlaps so little with that on rational behavior. For a review of the argument-types employed about ultimate ends, see Stuart Rachels, ‘A Defense of Two Optimistic Claims in Ethical Theory’, Philosophical Studies 112.1, January (I) 2003, pp. 1–30, sect. 2.

34 Parfit actually defines not irrational as ‘not open to rational criticism’ (Reasons and Persons, p. 119). Thus, I have substituted ‘rational’ for ‘not irrational’. Parfit's definition can be cleaned up a bit. As it stands, it entails that one must act irrationally when every possible action is open to some rational criticism. But one still acts rationally when one's act is the best of the lot. So, a better definition of ‘rational’ is ‘open to the least amount of rational criticism’. Making this change in the text would not materially affect the discussion.

35 Personal correspondence, 29 October 2001.

36 Compare Alston on paradigm cases of justified belief: William Alston, ‘Epistemic Desiderata’, Philosophy and Phenomenological Research 53.3 (September 1993), pp. 527–51, at pp. 536–7.

37 Of course, the act would be rational on the self-interested use, if on that use one is rationally permitted to forego one's greater good for moral reasons.

38 Baier, ‘Egoism’, p. 204.

39 Parfit says that this is the main thesis of Part II on p. 120.

40 Gibbard thinks endorsement is central to the meaning of ‘rational’. See Wise Choices, pp. 6, 10, 20.

41 I thank Jonathan Bennett for suggesting this genus/species analysis. And I thank William Fitzpatrick for making a similar suggestion.

42 Gibbard, Wise Choices, p. 12.

43 A different reply is also possible. An instrumentalist might say that (B) is coherent, since even if giving weight to my future happiness doesn't promote my present goals, it probably promotes my future goals, since I am likely to care about my future happiness in the future.

44 On a related note, Scanlon says: ‘Given that there are reasons for action other than those provided by an agent's own interests, I see no justification for giving this one class of interests such special status’ (What We Owe to Each Other, p. 31).

45 See Robert H. Frank, Thomas Gilovich and Dennis T. Regan, ‘Does Studying Economics Inhibit Cooperation?’, Journal of Economic Perspectives 7.2 (Spring 1993), pp. 159–71.

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