Some Difficulties For the Classical Model of Rationality

1. Some Difficulties For the Classical Model of Rationality Jim Fahey Dept. of Cognitive Science Rensselaer Polytechnic Institute

2. Some Difficulties For the Classical Model of Rationality • A. Believing Rationally • (i) The standard account of Knowledge and its Problems • (a) Paradoxes of Confirmation • (b) Paradoxes of Knowing/Believing • B. Acting Rationally • (i) “The Classical Model” – HumeanMeans-End Rationality • (ii) The Rational Choice/Maximize Expected Utility/Rational Actor Model

3. Some Difficulties For the Classical Model of Rationality • C. Can the Classical Model Be Extended to Cover Actors Acting Rationally Together? • (i) Social Cooperation – The Prisoner’s Dilemma • (ii) Social Inequality – The Ultimatum Game • (iii) Distributive Justice – Rawls’ “Veil of Ignorance” • D. Acting Rationally – External Problems • (i) Beliefs/Desires as “sufficient causes” – Newcomb’s Problem, Free Will and Akrasia • (ii) Commitments and Rationality – Why belief/desire accounts are not enough • (iii) Changing the preference function – practical abduction and a misreading of Hume.

4. A. Believing Rationally • Knowing About the Worldwe divide intoKnowing That vs. Knowing How(Epistemic Cognition) (Practical Cognition)We focus initially on “knowing that.” • Some Platitudes on Knowing That:“To know something you must believe it.”“Knowledge is more than a lucky guess.”“You can’t know something false.”

5. A. Believing Rationally (cont.) • In accord with these platitudes, since the time of Plato the starting point for attempts to analyze the nature of “knowing that” or “propositional knowledge” has been the view that: • If an entity S knows that some proposition P, then • S Believes that P • P is Justified for S • P is True

6. A. Believing Rationally (cont.) • But among the most serious problems for epistemology is What is justification? and attempts to answer this question yield many paradoxes with respect to believing rationally. • The Paradox of the Ravens (R. M. Sainsbury) • So far all of the ravens I have observed are black. By the Generalization Principle. • G: A generalization is confirmed by any of its instances • it seems to follow that each of my observations of black ravens supports the claim that • All ravens are black.

7. A. Believing Rationally (cont.) • But I also have a priori reason to hold the Confirmation Equivalence Principle. • E: Logically equivalent statements are confirmed/disconfirmed by identical evidence. • The problem is that All ravens are black is logically equivalent to All non-black things are non-ravens and that this is confirmed by the existence of a green frog. • So, by G and E, the existence of a green frog confirms that All ravens are black. But how can this be?

8. A. Believing Rationally (cont.) • Similarly, Goodman’s Grue Paradox: • Given G, my observing of a green emerald confirms BOTH the generalization thatAll emeralds are green, AND the generalization thatAll emeralds are grue, where grue is: • Grue = def., [observed by me and green]or [not observed by me and blue]. • If we assume that there are emeralds that I have not observed, how can my observation of a green emerald confirm each member of this logically inconsistent pair?

9. A. Believing Rationally (cont.) • In addition to the foregoing paradoxes of confirmation, we find many other paradoxes of belief/knowledge that provide difficulties for the notion of believing rationally. I list some of these in passing: The paradox of the Surprise Quiz The lottery paradox Gettier type counterexamples … • All of these continue to bedevil the notion of believing rationally.

10. B. Acting Rationally • The foundation of “The Classical Model” – Humean (David Hume) Means-End Rationality • Reason is, and ought only to be the slave of the passions, and can never pretend to any other office than to serve and obey them. … … ‘tis only in two senses that any affection can be called unreasonable. First, when a passion such as hope or fear, grief or joy, despair or security, is founded on the supposition of the existence of objects, which really do not exist. Secondly, When in exerting any passion in action, we chuse means insufficient for the design’d end, and deceive ourselves in our judgment of causes and effects.Where a passion is neither founded on false suppositions, nor chuses means insufficient for the end, the understanding can neither justify nor condemn it. ‘Tis not contrary to reason to prefer the destruction of the whole world to the scratching of my finger (Treatise, p. 415-16).

11. B. Acting Rationally (cont.) • Russell sums up this Humean view (incorrectly, I think, but more on that later) in what comes to be thought of as the “Classical Model of Rationality.” • ‘Reason’ has a perfectly clear and precise meaning. It signifies the choice of the right means to an end that you wish to achieve. It has nothing whatever to do with the choice of ends (1954, p.8).

12. B. Acting Rationally (cont.) • Maximize Expected Utility Theory/Rational Actor/Game Theory Models • Formalizations/refinements of the classical model have achieved wide currency. To illustrate, the flavor of these formal constructs, consider a lottery. • In general we consider a lottery to be a “better lottery” to the extent that it has a higher payoff and affords a greater chance of winning. This suggests a generalPrinciple of Rational Action. • Act so as to maximize the “desire fulfillment” (utility) you can expect from your action.

13. B. Acting Rationally (cont.) • Only slightly more formally (R. M. Sainsbury): • Where A1, A2, … An are actions, andO1, O2, … On are outcomes of actions andU(O) stands for the Utility of some outcome andEU(A) stands for the Expected Utility of some action,we say • EU(A1)=[prob(O1/ A1)*U(O1)]+[prob(O2/ A1)*U(O2)]+ …If we are trying to decide which among a pair of actions A1 or A2 is more rational we calculate the respectiveEU’s for each of those actions and choose accordingly. • This, according to the Classical Model, just isRational Action.

14. B. Acting Rationally (cont.) • There is no question that the Classical Model and its refinements provide important insight regarding what counts as rational action. • If agents:have preferences reflecting their wants;can make tradeoffs among those wants;can maximize utility by choosing actions based on their perception of resources, probable nature of interactions with the environment and beliefs regarding probable outcomes; they can be rational actors in the sense outlined by the Classical Model. • And Gintis, for example, argues that, “The rational actor model is ubiquitous because any evolved life form is likely to conform to its consistency conditions over some range of actions.”

15. C. Can the Classical Model Be Extended to Cover Actors Acting Rationally Together? • But the Classical Model may have shortcomings as well -- I begin by outlining some of its purported difficulties in the “social realm” as suggested by the playing of certain multi-player games. • But to provide the Classical Model with even a “shot” at dealing with multi-player games, we must add to the knowledge of the players a kind of common knowledge along the following lines (see Colman).

16. C. Can the Classical Model Be Extended to Cover Actors Acting Rationally Together? • CKR1. The specification of the game, including the players’ strategy sets and payoff functions, is common knowledge in the game, together with everything that can be deduced logically from it and from CKR2. • CKR2. The players are rational in the sense of the classical model, hence they always choose strategies that maximize their individual expected utilities, relative to their knowledge and beliefs at the time of acting. (By CKR1, this too is common knowledge in the game.) (Colman p. 7)

17. C. Can the Classical Model Be Extended to Cover Actors Acting Rationally Together? • Given this, consider the “Prisoner’s Dilemma.” • The environmental conservation officer has strong circumstantial evidence that both you and I were out on the lake fishing together and he knows for a fact that neither of us has a license. (There is a big fish flopping around in our boat and he saw us throwing what may have been fishing tackle overboard.) He and his partner arrest us and keep us separated on the way into town. One at a time we are taken before the local magistrate who gives to each of us the following list of possible penalties.

18. C. Can the Classical Model Be Extended to Cover Actors Acting Rationally Together? • The Penalties: • (1) If one of us admits that he/she is guilty and the other one doesn’t, the one who doesn’t will spend 10 days in jail while the one who confesses will get off. • (2) If we both admit our guilt, we will each spend 5 days in jail. • (3) If neither of us admits guilt, we will be convicted on a lesser charge (unlawfully imprisoning a fish in a boat) and each of us will be sentenced to spend one day in jail.

19. C. Can the Classical Model Be Extended to Cover Actors Acting Rationally Together?

20. C. Can the Classical Model Be Extended to Cover Actors Acting Rationally Together? • Moreover, we build into the story that(i) each of us is concerned only with getting the shortest sentence for her/himself and(ii) neither of us has any information about the likely behavior of the other except that the other is “classically rational.” • We continue to be held separately. What course of action is the rational one for each of us?

21. C. Can the Classical Model Be Extended to Cover Actors Acting Rationally Together? • But if there is no straightforward answer here, does this suggest the following argument? • (1) If the Classical Model is an adequate model of rational action, then it adequately models rational social interactions. • (2) The Classical Model DOES NOT adequately model rational social interactions. • ----------------------------------------------------------- • (3) The Classical Model is NOT an adequate model of rational action.

22. C. Can the Classical Model Be Extended to Cover Actors Acting Rationally Together? • In support of the view that the Classical Model has great difficulty in accounting for crucial features of social rationality, consider the Ultimatum Game.

23. C. Can the Classical Model Be Extended to Cover Actors Acting Rationally Together? • (I follow Gintis’s account) • In the ultimatum game, under conditions of anonymity, two players are shown a sum of money, say $10. One of the players, called the “proposer,” is instructed to offer any number of dollars, from $1. to $10., to the second player, who is called the “responder.” The proposer can make only one offer. The responder, again under conditions of anonymity, can either accept or reject this offer. If the responder accepts the offer, the money is shared accordingly. If the responder rejects the offer, both players receive nothing. Since the game is played only once and the players do not know each other’s identity, a self-interested proposer will offer the minimum possible amount, $1. and this will be accepted.

24. C. Can the Classical Model Be Extended to Cover Actors Acting Rationally Together? • But when actually played, the self-interested outcome never obtains. • Cross cultural tests … • It seems that we have empirical evidence based on human behavior from across the Globe that purely self-interested behavior in social interactions is irrational.

25. C. Can the Classical Model Be Extended to Cover Actors Acting Rationally Together? • Finally, results such as those obtained in the Ultimatum Game suggest that we should look at such notions as Distributive Justice from the standpoint of social rationality. In this vein, consider John Rawls’s discussion of distributive justice principles in terms of the “Veil of Ignorance” • What are the general principles we should employ to provide a rational distribution of the goods and services of a society?

26. C. Can the Classical Model Be Extended to Cover Actors Acting Rationally Together? • Rawls proposes that we adopt the principles we would choose from behind the veil of ignorance. • Rawls suggests that we each think of ourselves as being ignorant of: • One’s place in society, one’s class, sex or social position;One’s talents/abilities, intelligence, strength, vitality …One’s specific wants, desires, beliefs, … • All I know about myself is that I prefer more social goods than less and that I will not make spiteful choices based on envy. Moreover, I do know, in general, about the productive capacities of my society.

27. C. Can the Classical Model Be Extended to Cover Actors Acting Rationally Together? • Rawls argues that from behind his veil of ignorance, two principles of distributive justice will be chosen. • DJ1. Equality in the assignment of basic rights and duties; • DJ2. Social and economic inequalities, are just only if they result in compensating benefits for everyone (in particular, for the least advantaged members of society).

28. C. Can the Classical Model Be Extended to Cover Actors Acting Rationally Together? I would argue that empirical results such as those regarding the Ultimatum Game show that some principles along the lines of those suggested by Rawls are accepted by humans as being necessary constituents of any theory of rationality that hopes to account for “social rationality.”

29. D. Acting Rationally: External Problems • ARG #1. One of the assumptions of the Classical Model is that all of my actions can be explained in terms of my beliefs and desires. • In his Rationality and Action, John Searle argues that such a view is at odds with our ordinary understanding of free rational actions. On Searle’s (restatement of a very old) argument, rationality requires that there be “gaps.” That is, there are gaps between • Reasons GAP Decision GAP Action GAP Action (start) (completion)

30. D. Acting Rationally: External Problems • In essence, Searle argues that if we are to separate rational actions from such things as addicted and otherwise compelled behaviors there must be a kind of “radical openness” embedded within rational action. Likewise, Searle argues that if we are to explain such things as weakness of will (akrasia), we must hold that rationality requires “gaps.”

31. D. Acting Rationally: External Problems • In support of this view, consider Newcomb’s Problem. • There are two boxes, A and B. • You have just one of two choices: • (i) You may open both boxes A and B. • (ii) You may open only box B. • A purportedly perfect predictor has put $1000. in box A. • If the predictor predicts that you will open both boxes, then the predictor puts $0. in B. If the predictor predicts that you will open just box B, then the predictor puts $1,000,000. in B. • QUESTION: What is the Rational Choice?

32. D. Acting Rationally: External Problems • Schematically:

33. D. Acting Rationally: External Problems • It seems that before you make your choice, either the predictor has or has not put $1,000,000. in B. • But if one follows Searle and holds that rationality requires gaps, there can be no rational action since the perfection of the predictor rules out the possibility of Gaps. Either your actions are determined or they backwardly cause the predictor’s actions. In either case, NO GAPS. • Again, here we have an updated version of an ancient argument.

34. D. Acting Rationally: External Problems • ARG. #2. A second argument put forth by Searle against the view that all of my actions can be explained in terms of my beliefs/desires is the Bar Tab Argument. • Searle says that when he buys a beer and pays his tab, his “introspective investigation” yields no finding that he desires to pay his tab. Why then does Searle pay his tab? Searle argues that he does so because he has made a commitment to pay his bills.

35. D. Acting Rationally: External Problems • Searle’s argument dovetails nicely with a long held view in sociology which emphasizes internalization of norms. Searle, however, holds that these commitments that contribute to our actions, (rational or otherwise) are not merely societally based but that at least some of them come from the self.

36. D. Acting Rationally: External Problems • ARG. #3. Finally, consider Russell’s claim that • ‘Reason’ has a perfectly clear and precise meaning. It signifies the choice of the right means to an end that you wish to achieve. It has nothing whatever to do with the choice of ends (1954, p.8). • I suggested earlier that this quote from Russell does not in fact capture Hume’s view on the relation between reason and desire. Here is the small print that we passed over earlier in our quote from Hume.

37. D. Acting Rationally: External Problems • … ‘tis only in two senses that any affection can be called unreasonable. First, when a passion such as hope or fear, grief or joy, despair or security, is founded on the supposition of the existence of objects, which really do not exist. Secondly, When in exerting any passion in action, we chuse means insufficient for the design’d end, and deceive ourselves in our judgment of causes and effects.

38. D. Acting Rationally: External Problems • If we agree with Searle that there are gaps and that we make commitments that along with our beliefs and desires participate in the production of actions, perhaps it still makes sense for us to talk about our having of preference functions that provide a basis for our “gappy actions.” • But if we have such preference functions (a kind of belief, desire, commitment function), the classical model would still not allow that reason could provide the basis for changing my preference function.

39. D. Acting Rationally: External Problems • But even Hume would not agree. Note that Hume points out that there are conditions under which reason can provide the causal impetus for a change of passion. If my reasoning reveals that a purported object that caused my passion does not in fact exist, then my passion may quickly vanish. (If I discover that what I thought was a snake was in fact a rope, my desire to leave the room may disappear in a trice.)

40. D. Acting Rationally: External Problems • Likewise, if I have come to desire becoming wealthy as a result of my belief that I have inherited an Aladdin's lamp, then when I find through reasoned investigation that there is no resident genie, my desire for wealth may well melt away. • In each of these cases, through an exercise of reason, I have achieved a resulting change in passion. Such exercises I call practical abduction --a change in passion caused by an exercise of reason.

41. D. Acting Rationally: External Problems • So in sum, as regards what I have called “external problems” for the Classical Model of acting rationally, I have considered the arguments: • ARG. #1 – Searle’s restatement of the ancient argument that rational actions require the existence of gaps. • ARG #2 – Searle’s argument that in addition to beliefs and desires there are commitments that contribute causally to the production of my actions. • ARG. #3 – An argument that Reason does have a role to play in the changing of my passional nature, a process that I call practical abduction (see Millgram).