Leading You Down the Choice Path: Rational Persuasion as Collective Rationality Bruce Chapman * This paper explores the advantages of a form of non-arbitrary path dependence within social choice called rational persuasion_ Persuasion is characterized as conversationally leading one's protagonist down a particular choice path to a particular result. The choice path is enticing, or rationally persuasive, because it "makes sense" in a way that alternative choice paths do not. It tends to group, or partition, alternative choices in a way that either allows us to think of the partitioned alternatives as instantiations of some concept or presents us with some issue that we recognize as important in the choice situation. Not all partitions of the alternatives do this equally well. Nor are they as easy to talk about under the shared concepts that will organize, and be persuasive in, conversation. In this respect rational persuasion is a partition dependent idea. However, the paper also shows that the partitions have to be presented in a certain order if social choices {and the individual preferences that give rise to them} are going to be sensitive to the issues at stake as well as sensible under them. So, in the final analysis, rational persuasion must not only be partition dependent, but path dependent as well. However, contrary to what Kenneth Arrow suggests in Social Choice and Individual Values, such path dependent social choice is not arbitrary. Indeed, because rational persuasion is a form of social interaction that is both sensible and sensitive to the issues that divide us, persuasion is an exhibition of our collective rationality. It is a mistake, under the idea of a social preference ordering {which precludes path dependent social choice}, to define it away as a possible approach to the social choice problem.
* Faculty of Law, University of Toronto, (
[email protected]). A first draft of this paper was originally prepared for a workshop organized by Ariel Rubinstein on "Economics and Language", held at Madrid in June 2006 and sponsored by the Urrutia Elejalde Foundation. Subsequent drafts were presented to the Siena-Toronto-Tel Aviv Workshop in Law and Economics, Department of Economics, University of Siena, June, 2007; the Faculty Workshop, Faculty of Law, University of Toronto, November 2007; the Jurisprudence Symposium, Oxford University, February 2008; and at the "Symposium on Emerging Paradigms of Rationality", Centre for the Study of Rationality, University of Minnesota Law School, November 2008. I am grateful for the helpful comments I received on all of these occasions and to the Social Science and Humanities Research Council of Canada for research funding.
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Introduction 1. Sense and Sensitivity on the Choice Path: The Fine Art of Rational Persuasion II. Persuasion, Shared Reasons and Rational Social Choice Conclusion
Introduction In the final chapter of the second edition of Social Choice and Individual Values, Kenneth Arrow reflects on some of the scholarly responses to the first edition of his famous book. 1 That first edition, of course, had demonstrated that no procedure satisfying certain minimally acceptable conditions for making social choices, interpreted there as aggregating the different preferences of individuals into corresponding preferences for the group as a whole, was possible. One of the responses that Arrow considers in his final chapter is a criticism offered by James Buchanan. 2 Buchanan had argued that rationality, and rational choice, can only subsist in individuals; the idea of some sort of collectively rational social preference ordering simply makes no sense. Arrow might have responded to this critique in any number of ways. For example, he might have emphasized that if the criteria for reasonable social choice generated a social preference cycle (in violation of his ordering requirement), then there would be a danger of instability as social choice incessantly moved on, around the cycle, to a more socially preferred alternative. Or he might have said that if the social choice rule avoided this instability by stopping at some (or any) point in the cycle, rather than moving on, it would be violating one of the choice criteria that it had sought to satisfy, something that would make a nonsense of having such criteria in the first place. So, the collective rationality requirement, far from effecting some illegitimate application of an individualistic property to a society, was simply a way of capturing the sensible idea that methods of social choice should have a
1. Kenneth J. Arrow, Social Choice and Individual Values, 2d ed. (New Haven, Conn.: Yale University Press, 1963). The first edition of Arrow's book appeared in 1951. 2. James M. Buchanan, "Social Choice, Democracy, and Free Markets" (1954) 62 J. Pol. Econ. 114 at 116-18.
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settled way of satisfying the very criteria that they had otherwise identified for themselves as reasonable. Interestingly, however, Arrow offers up quite a different defence of his collective rationality requirement. He argues that if the social choice rule does not generate a fully transitive social preference ordering, then the final social choice from the set of alternatives will depend on the path, or order, in which the different alternatives are considered. 3 Arrow seems to think that this sort of path dependence is too arbitrary. The final social choice from a set of available alternatives should turn only on some intrinsic property of that chosen alternative in comparison to other alternatives as possible final choices. It should not depend on the sequence in which the different alternatives happen to be compared with one another. 4 One can easily imagine process theorists (and non-consequentialists more generally) resisting this idea that the choice sequence or path should, from the very start, be deemed irrelevant to the design of an appropriate social choice rule. Some, like the "pure procedural justice" proponent mentioned by Rawls, might even suggest that the choice 3. Supra note 1 at 120. For excellent discussion of the exact logical relationship that exists between transitivity as a collective rationality condition and path independence, see Charles R. Plott, "Path Independence, Rationality, and Social Choice" (1973) 41 Econometrica 1075. As Plott shows, full transitivity of the social preference relation (that is, transitivity of social preference and indifference) is not strictly required for ensuring path independence; quasi-transitivity (or transitivity of the strict social preference relation only) will do. 4. Philosophers are increasingly addressing these distinctions. See, for example, Jonathan Dancy's very interesting discussion of the differences between the 'intrinsic aspect view', the 'provenance view', and the 'alternative complementarity view' in his paper "Essentially Comparative Concepts" (2005) 1:2 J. Ethics & Soc. Phil. 1. The alternative complementarity view suggests that the choice between alternatives (even the choice between two given alternatives x and y) can turn on what other alternatives (say, alternative z) are available for choice at any point, a form of partition (or menu) dependence which is hard to explain on the intrinsic aspect view. (Given that their intrinsic aspects are not affected, why should the choice between two mutually exclusive alternatives x and y be influenced by the presence or absence of some third mutually exclusive alternative z in the partition of alternatives?) The provenance view converts that sort of partition dependence into a dependence on the "history" of choice, or how the different partitions are sequenced for the chooser. This is what Arrow and other social choice theorists typically refer to (and shun) as path dependence.
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sequence, process, or path is everything; whatever outcome results from an appropriate process of choice is the proper one. s However, we need not go so far as saying that process is everything, and the intrinsic properties of an outcome nothing, without sensing that Arrow's defence of collective rationality as path independence reveals something "partial" about his overall approach to social choice. In this paper, I explore the possible advantages of a form of nonarbitrary path dependence within social choice, which I call rational persuasion. Persuasion is characterized here as conversationally leading one's protagonist down a particular choice path to a particular result. The selected choice path is enticing, or rationally persuasive, because it "makes sense" in a way that alternative choice paths do not. It makes sense because it tends to group, or partition, alternative final choices together in a way that either allows us to see or think of the partitioned alternatives as instantiations of some concept or category, or that presents us with some issue which we recognize as important in the overall choice situation. We shall see that not all partitions of the alternatives do this equally well. Nor are they as easy to talk about under the shared concepts that will organize, and be persuasive in, conversation. In this respect, rational persuasion is a partition dependent idea. However, we shall also see that the partitions have to be presented in a certain order, or sequence, if social choices (and the individual preferences that give rise to them) are going to be sensitive to the issues and concepts at stake as well as sensible under them. So, in the final analysis, I will argue that rational persuasion must not only be a partition dependent idea, but a path dependent one as well. However, contrary to Arrow, I argue that it is not arbitrarily so. Indeed, because rational persuasion is a form of social interaction and social choice that is both sensible and sensitive to the issues that divide us, persuasion is an exhibition of our collective rationality. It is a serious mistake, under the idea of a social preference ordering, simply to define it away as one possible approach to the social choice problem. The paper is organized as follows. In Section II I show, by way of an example, how certain choice paths that lead to particular results make 5. John Rawls, A Theory o/Justice, rev. ed. (Cambridge, Mass.: Belknap Press of Harvard University Press, 1999) at 75.
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more sense of, and are more sensitive to, the issues that seem to be at stake in the choice situation. We will see that this analysis requires us to work with the possibility of intransitive preferences, not deny it. The example I use begins as one involving only individual choice, but I argue that the introduction of a persuader, even a persuader whose preferences might conflict with our chooser, does not affect the persuasiveness of the path dependent result. The persuader persuades because he addresses, under shared reasons organized around a sensible and sensitive choice path, the issues that are important to the chooser. Shared reasons bring an order to conflicting preferences in a social choice situation, just as the sensible and sensitive choice path brought order to the individual's own intransitive preferences in an individual choice situation. Section III argues that shared reasons, and the obligation to be persuasive, can do more than resolve conflicts in preferences. As an example from legal decision-making will show, the obligation to be persuasive can also destabilize shared preferences in a way that is useful to social choice. Social choice cycles result in large part because too many decisive coalitions arise too easily out of shared preferences. Shared reasons can bring a useful discipline to these preference cycles. The result, again, is path dependent choice, that is, choice arising out of those partitions that make conversational sense of, and (when arranged in the right order) are sensitive to, the issues that divide us. The paper concludes in Section IV.
I. Sense and Sensitivity on the Choice Path: The Fine Art of Rational Persuasion Imagine that you and I disagree about some apparently basic proposition w. I say w, or "It is white", and you say not-w, or "It is not white". Is there anything we can do to resolve our disagreement rationally? The disagreement seems to be a matter of belief, one that can only be addressed empirically, that is, if each of us has another close look at the object in dispute. There does not seem to be anything that I can merely say to persuade you, rationally, to accept w. But that is not exactly right. Suppose that I can get you to accept some other proposition s. And, further, suppose that I can also get you
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to concede the implication (5 -+ w). Now, surely, I will have persuaded you to accept w. For example, it might be that the source of our disagreement on the colour of this object is the conditions under which we are viewing it. We are looking at it in silhouette against the sunset and the object appears quite dark. But I can get you to concede (from the shape of the silhouette) that 5, or "It is a swan", and that (s -+ w), or "All swans are white". So now, it seems, I have given you some reason for agreeing with me that w, or "It is white", and all without having another close look at the object. It seems then that I have rationally persuaded you. But this is not quite right either. It is true that if you accept 5 and, further, accept (5 -+ w), then, if you do not accept w, you are not thinking entirely as you should be. Yours is a failing of rationality, and it was this that my simple argument was meant to reach in convincing you, rationally, to accept w. Despite this, my argument does not give you any reason to accept w, where reasons attach to one of the three propositions that my argument has shown to be inconsistent. Indeed, our example suggests why this must be so. We all know (now) that it is false that (s -+ w); not all swans are white. Thus, mere acceptance of both 5 and (s -+ w) does not (at least as such) give you a good reason to accept w. You may still have good reason to accept not-w. Certainly you do if this swan is black! Nevertheless, if you accept both 5 and (5 -+ w), then it is true (as my argument was originally meant to suggest) that, if you do not accept w, you are not thinking as you should be. Rationality strictly requires you to reject at least one proposition from the triple {s, (s -+ w), not-w}. However, it does not require you to reject not-w, or to accept w, in particular. Indeed, it does not even give you a reason Qet alone a good reason) to do that. 6 So it seems I have not been as persuasive as I had hoped to be. 6. John Broome has effectively made this point over a number of recent articles; see, for example, his "Does Rationality Give Us Reasons?" (2005) 15 Phil. Issues 321 at 323. Rationality requirements, he argues, have 'wide scope', that is, they govern the relations that should hold across the different mental attitudes (desires, beliefs, intentions) that you might have. Rationality does not require, or give you any reason for, holding some particular mental attitude. The latter "narrow scope" obligation is more characteristic of reasons, which go to the relations that should hold between (the facts of) your situation and a particular mental attitude. For example, that p is true is a good reason for believing
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Further, if our disagreement had been prescriptive rather than descriptive in nature, the discussion would likely have gone the same way. Suppose I prefer social outcome x to social outcome z and you prefer the reverse. Again, it might seem that these preferences are simply "given" in the way usually accepted by the decision theorist, and there is little we can say or do, rationally, to resolve our disagreement. De gustibus non est disputandum. But even the decision theorist does not quite accept that. It seems that his deference as empiricist to "given" preferences is qualified at least to this extent: preferences must conform to the requirements of rationality. Consider, for example, what the decision theorist Leonard Savage says he does when it is pointed out to him that his own preferences appear intransitive, that is, that they indicate he prefers x to y, Y to z, and z to x: [W]henever I examine such a triple of preferences ... I find that it is not at all difficult to reverse one of them. In fact, I find on contemplating the three alleged preferences side by side that at least one among them is not a preference at all, at any rate not any more.'
Presumably, if Savage is prepared to bring this much rationality to bear upon his own preferences and, in the face of irrationality, change what is (for him) a "given" preference to no preference at all, then he would not be above trying to do the same against someone else whose preferences for some important social choice disagreed with his own. Presumably, he would try to expose his antagonist's opposing preference to a test of transitivity, based on other preferences that the antagonist already has, and thereby reduce the contested preference (the one he disagrees with) to a nullity. This is what rational persuasion against conflicting preferences might look like.
p (as a matter of narrow scope), but rationality requires you not to believe (as a matter of wide scope) both p and not-p, something we can be sure of regardless of the truth of p (that is, regardless of what reasons there might be for you to believe it). 7. Leonard J. Savage, The Foundations of Statistics (New York: John Wiley & Sons, 1954) at 21 [emphasis added). The view that a preference intransitivity will be corrected if the preferences are carefully reconsidered is common; see e.g. Alex Voorhoeve & Ken Binmore, "Transitivity, the Sorites Paradox, and Similarity-Based Decision-making" (2006) 64 Erkenntnis 101 at 102, 111.
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However, if we take Savage's suggestion to our prescriptive disagreement, where I prefer social outcome x to social outcome z and you have the reverse preference, then the end result would appear to be the same as with our descriptive disagreement. At best, all I can do is get you to accept the rationality constraint inherent in the transitivity requirement, that is, not-{x preferred to y, y preferred to z, z preferred to x), and then simply hope that this induces you to reject the last preference, the one that divides us. But you need not take this last way out, and transitivity, as a general normative requirement of rationality, does not give you any particular reason to do SO. 8 SO, again, it seems that I might not be as persuasive as I had hoped to be. The problem seems to be that these forms of rational persuasion only seem to get us to the point of seeing a possible inconsistency, but an inconsistency can be resolved by relaxing anyone of the propositions, or preferences, that are inconsistent. Is there any reason to think that rationality might order our prOpOSItIOnS or preferences more substantively so that one of them in particular (the preference or propositional claim that divides us) must give way to the others? This would be more helpful, since then rational persuasion would have more of the focus that we need; it would be brought to bear upon the very issue that divides us and not leave any room for one of us to resolve the larger inconsistency by making the required adjustment somewhere else and in a way that leaves our dispute untouched. 9 8. See Robert Nozick, The Nature of Rationality {princeton: Princeton University Press, 1993} at 159: ("The requirement that preferences be transitive should not be read to state that if a person prefers x to y and prefers y to z, then that person should prefer x to z. Rather, the requirement of transitivity should be read to state: it should not be the case that a person prefers x to y, prefers y to z, and does not prefer x to z. From this condition, no detachable conclusion can be derived about what particular preference a person should have.") 9. This would appear to be a disadvantage that is inherent to rational as opposed to reasoned persuasion. Recall (supra note 6) that reasons go to a relationship that exists, or should exist, between one of your attitudes (beliefs, intentions, desires) and your situation, e.g., if p is true, you have reason to believe p; if the building is burning, you have reason to form the intention of leaving it. So by providing information to you about your situation I am engaged in reasoned persuasion. (For an example of how an institution might be designed to provide more effectively for reasoned persuasion because it maximizes the probability that the listener will accept only true propositions, see Jacob
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That is the most obvious benefit of a more powerful and focused form of rational persuasion. But I think that there would be another important benefit as well. Under the more focused approach, we would effectively be using rationality to choose which given preference or propositional claim to privilege rather than using it, as Savage does, to dictate that, contrary to what appears given, we have no such preference or have made no such propositional claim at all. tO And in certain choice situations this approach seems to reflect more accurately what is at stake. When it is pointed out that our preferences conflict or are inconsistent, for example, it sometimes still seems that each preference is real, not absent. ll What is needed is some ordering over the conflict, not some Glazer & Ariel Rubinstein, "A Study in the Pragmatics of Persuasion: A Game Theoretical Approach" (2006) 1 Theoretical Econ. 395.) Rationality, on the other hand, goes to the relationship that exists between your different attitudes, however the world or your situation might be. You ought not to believe p and believe not·p, regardless of what p says, or what the evidence for p is, etc. So in persuading you by trying to catch you in an inconsistency across your attitudes, I am only rationally persuading you, and I seem not to be in a position to engage you in any particular or required resolution of that inconsistency. This article advances an account of persuasion that involves offering reasons (arising out of how the chooser "sees" his situation and can sensibly organize it under concepts) for resolving an inconsistency of attitudes (preferences) in a particular way. In this it falls somewhere between a purely rational and a purely reasoned form of persuasion; see infra note 15 and accompanying text. For discussion of persuasion as a way of getting someone to "see" the situation in a certain way, and not as a way to get someone to change her beliefs/information or desires/preferences, see Frederic Schick, Ambiguity and Logic (Cambridge: Cambridge University Press, 2003) at 60·78. 10. See Alex Viskovatoff, "Rationality as Optimal Choice versus Rationality as Valid inference" (2001) 8 J. Econ. Methodology 313 at 321: "[I]f we do notice preferences that conflict, we just choose anyway, not by resolving the conflict by recalibrating our preferences so that they no longer conflict, but by 'choosing' which set of conflicting preferences to privilege." 11. The continuing presence of the preference, even if it goes unsatisfied after some kind of rationally ordered choice, helps to explain the psychological state of "regret" that we feel (often properly) in making that rational choice rather than the one favoured by the preference that went unsatisfied; on this see Bernard Williams, "Ethical Consistency" in Problems of the Self (London: Cambridge University Press, 1973) 166 at 170, 172·76. For a suggestion that the accommodation of such attitudes of regret or remorse (or even disgust) signals how a philosopher (rather than an economist) might approach hard questions of ethical choice, see Geoffrey Brennan, "Lessons for Ethics from Economics?" (2008) 18 Phil. Issues 249 at 257.
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invalidation of one of the preferences so that the conflict altogether disappears or, as in Arrow's social choice framework, is simply defined away. The following example is helpful in illustrating the point. It also suggests how an ordering of inconsistent or conflicting preferences might be devised. Suppose a guest is offered a choice of fruit at a dinner party.12 If she is offered a large apple, A, or a large orange, 0, she would choose A. Both fruits are large, and all else equal she prefers apples to oranges. (Here, contrary to the usual adage, apples and oranges are comparable.) If offered a choice between the large orange and a small apple, a, she would choose the larger fruit, the orange. So she would choose A over 0, and o over a. Thus far nothing seems to be out of the ordinary. Her choices reveal preferences that are driven largely by hedonism, that is, the comparative pleasure she derives from fruits of a particular kind and size. However, in a choice between A and a, a different consideration arises. For now there is an issue of etiquette to be addressed. The rule of etiquette, let us suppose, is that one should never choose the larger of two items of the same kind ("Always take the smaller of the two"). So, in a choice between A and a, she would choose a. However, now her three choices reveals an apparent intransitivity of preference: A preferred to 0, 0 preferred to a and a preferred to A. Savage's suggestion for the dinner guest is that she should re-examine the three preferences. Then she will be able to reverse one of them, discovering that it was not really her preference at all. But the dinner guest will protest that this misrepresents her situation completely. After her re-examination, each of her three preferences continues to reveal
12. This example is now much discussed. The earliest published analysis of it, of which I am aware, is in Philip Pettit, "Decision Theory and Folk Psychology" in Michael Bacharach & Susan Hurley, eds., Foundations ofDecision Theory (Oxford: Basil Blackwell, 1991) at 163. The example, and close variations of it, are also analyzed in Paul Anand, "The Philosophy of Intransitive Preference" (1993) 103 Econ. J. 337 at 344; Amartya Sen, "Internal Consistency of Choice" (1993) 61 Econometrica 495; Amartya Sen, "Is the Idea of a Purely Internal Consistency of Choice Bizarre?" in ].E.]. Altham & Ross Harrison, eds., World, Mind, and Ethics (Cambridge: Cambridge University Press, 1995) at 19; Amartya Sen, "Maximization and the Act of Choice" (1997) 65 Econometrica 745 at 762; and Bruce Chapman, "Law, Incommensurability, and Conceptually Sequenced Argument" (1998) 146 U. Pa. L. Rev. 1487 at 1498-99, 1503.
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something that is true for her about that pairwise choice. Etiquette simply is not at issue when the choice sets are (A, 0) and (0, a), so she is at liberty in these situations to indulge her purely hedonistic preferences for fruit, A over 0, and over a. However, when the choice set is (A, a), etiquette is at issue, and there she really does feel the obligation to choose the smaller apple, that is, to choose a over A. Not that etiquette is some absolutely (or lexically) prior value for her; at some point the difference between the size of the two fruits might be large enough to trump the obligation that she feels (at least to some extent) to observe the rules of etiquette. But she claims that she has not yet arrived at that point in this choice and that every preference she now has, however intransitive they might be in combination, is a genuine one that can withstand the re-examination that Savage recommends. Nevertheless, some might still wonder how our dinner guest will choose. She cannot maximize; after all, for every possible choice she might make there is another choice that she prefers. Will she cycle endlessly through her preferences, never settling on anyone piece of fruit? This prospect can be avoided, of course, if she is presented with a finite sequence of choices where previously rejected alternatives are not again presented for reconsideration. But then it seems that her final choice will be arbitrarily path dependent in exactly the way that Arrow feared, that is, dependent on the sequence in which the different fruits are presented to her. For example, if she is presented with the choice (0, a) first, and chooses 0, and then is presented with the remaining choice (0, A), she will end up choosing A, her most preferred option on purely hedonistic grounds. On the other hand, if she is presented with the choice (0, A) first, and chooses A, and then is presented with the remaining choice (A, a), she would end up choosing a. Finally, if the choice sequence is first over (A, a), and then over (0, a), she will choose 0. In other words, whichever alternative is not considered in the first pair will end up as the final choice in the sequence. An important question to ask, therefore, is whether anything can be said in favour of using one of these choice paths rather than the others. If not, then we will have simply, and unprofitably, shifted the burden of unresolved choice from the alternatives considered on their own to the choice paths that, so arbitrarily it appears, determine the final choice from those alternatives. However, if some of the choice paths are more
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sensible to articulate than the others, or are more sensitive to the issues that are genuinely in play than the others, then we might be on our way to a rational resolution of the conflict that exists between preferences over these alternatives. The final choice over these alternatives would still be path dependent, of course, but it would not be arbitrarily path dependent. So it is worth examining these different choice paths more carefully. The first of the three possible choice paths, "First (0, a), then (A, 0)", appears to avoid the etiquette issue altogether by never presenting the dinner guest with the choice set (A, a), that is, a choice set containing two fruits of the same kind. This might be opportune for a guest seeking a purely hedonistic way out of her dilemma. But it seems likely that, if the choice sequence unfolds quickly enough, she will have to concede that etiquette is at issue because there are really three pieces of fruit on offer to her. The first choice path makes it appear that the choice among the three fruits is all about hedonism when, of course, it is not; it is also about etiquette. However, the choice is not only about etiquette and this is where the second choice path, "First (A, 0), then (A, a)", falls into the opposite sort of error. It incorporates a choice between the two apples as fruits of the same kind and so accommodates the fact that etiquette is an issue to be addressed in the choice. But it does so in a way that, in the result, makes etiquette the only issue, a result that seems just as inappropriate as ignoring it altogether. For while the dinner guest is allowed momentarily to entertain her hedonistic preferences for fruit in the first choice over (A, 0) by choosing A, this hedonistic moment in the choice sequence is almost immediately obliterated by the obligations of etiquette in the choice of a from the remaining pair (A, a). This final choice is the worst possible outcome from the hedonistic point of view; etiquette seems to have fully determined her final choice of fruit even though, it seems to her, hedonism also should have had some role to play. So neither of these two choice paths, that is, neither "First (0, a), then (A, 0)" nor "First (A, 0), then (A, a)", properly captures the fact that the dinner guest feels that there are two criteria that are genuinely relevant to her choice of fruits, namely hedonism and etiquette, not just one or the other. In a way this is the same point that she wanted to
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assert against Savage's suggestion that rationality must nullify one of her preferences, and she feels it no less here as a reason to reject both of the first two choice paths. It is worth noting that our chooser's reasons for rejecting each of the two choice paths are slightly different. The first choice path, by never presenting her with the choice set (A, a) at all-that is, by never presenting her with fruits of the same kind-fails because it does not partition the alternatives sensibly (that is, conceptually or categorically) into alternatives of the same kind. Yet etiquette is an issue in this choice situation and, as articulated here, it is a partition dependent idea {since it bears upon a relation between the alternatives within a choice set as being of the same kind, not on intrinsic aspects of the alternatives considered on their own).13 So we will need a partition dependent choice sequence to reflect this fact. However, our difficulties with the second choice path indicate that partition dependence on its own will not be enough. For the second choice path sensibly presents the issue of etiquette, by preserving the partition (A, a) as one of the choice sets. But it does so in an insensitive way. By presenting the etiquette issue second, it allows etiquette to completely overwhelm hedonism as a choice criterion. Thus, while in this choice path there is a formal, or partition dependent, accommodation of the two criteria that seem so salient for choice, the partitions are not sequenced in a way that allows each criterion to playa substantive role in determining what is finally chosen. So we need to do more than introduce partitions or choice sets that preserve etiquette as an issue; we also need to sequence the partitions as choice paths so that there is a serious and sensitive attention to these different issues. The third available choice path, "First (A, a), then (O, a)", does seem to allow our chooser to accommodate both of her choice criteria in a (formally) sensible and (substantively) sensitive way. When our dinner guest faces the first pair and chooses a, etiquette is recognized both formally as an issue under that choice set and substantively as a determinant of the choice that she makes from that set. And when she chooses from the second pair (O, a), she indulges her hedonistic preferences for fruit over the alternatives that remain. Thus, neither
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13. See supra note 4 and accompanying text.
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etiquette nor hedonism is ignored as an issue, and the sequencing of the issues does not totally exclude the impact of one or the other in influencing the final choice. Of course, our dinner guest is unlikely to work through her problem in this awkward and artificially structured way. More likely she will say something to herself like the following: "There are three fruits on offer. I cannot choose the large apple over the small apple because of the rules of etiquette. So I will choose the orange, the best hedonistic result for me in the circumstances." As a matter of purely internal reflection, this effectively captures the choice path which both makes sense of etiquette as an issue and is sensitive to the fact that both etiquette and hedonism are relevant choice criteria in this situation. However, in cases of social rather than individual choice, the analogous idea of an explicitly sensible and sensitive choice path might be more useful. Suppose, for example, that I have observed the dinner guest dithering over her choice, somewhat confused about what she should do. She might even be engaged momentarily in the Savage strategy, thinking about which of her preferences is really "not a preference at all". Fearful that virtually anything is permissible under such a strategy (more on this below 14), I intervene as a rational persuader and invoke the idea of a sensible and sensitive choice path. I appeal to the fact that, contrary to what Savage and Arrow would have her believe, she is right to feel that all of her conflicting preferences are real and not the stuff of self-delusion which must be either reflected away (Savage) or defined away (Arrow). To make sense of that very fact, I argue (using sense and sensitivity) that she should follow a particular choice path through the conflict and choose the orange. This process of choice, I suggest, comprehends her situation as she understands it, which makes the suggested choice path persuasive to her. Surely, then, if she chooses the orange, I can claim to have rationally persuaded her. I will have used the inconsistency in her preferences (the stuff of rational persuasion), but in a way that appeals to her situation (the stuff of reason) and brings her to a particular result. 14. See the text accompanying note 15 above, where I reveal that I might have my own reasons for being rationally persuasive in a very particular way, albeit in a way that the dinner guest has reason herself to find convincing.
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Some might think of me as an all too intrusive rational persuader. Why should I intervene in my dinner guest's private dilemma? Is this not a matter of individual choice, of something that should properly be left to her? However, I may well have my own self-interested motivations for the intervention. Perhaps I stand to get the large apple if I can only persuade other choosers ahead of me of their obligations under the rules of etiquette. If this is the case, then my rationally persuasive argument looks much more like it is addressing a true social choice problem where the preferences of different individuals over different social outcomes are in conflict. However, if my argument was persuasive before, it should be no less persuasive to the dinner guest now, just because it has become apparent that I have my own motivations for offering it. I have offered the dinner guest reasons, ordered around a sensible and sensitive choice path, for why she should resolve her preference dilemma in a particular way. The reasons, I have suggested, make sense to her. IS They also make sense to me, which is why I can offer them so easily. In this respect my argument for a particular choice path is socially persuasive; I offer reasons that both my dinner guest and I can share. These shared reasons are not undermined by the fact that our preferences (say, for the large apple) might conflict. Indeed, that shared reasons can provide a rational mechanism for resolving our differences in preferences over different social outcomes is precisely what is so promising about rational persuasion. Rational 15. That is, they make sense of how she herself understands her situation. Does this mean (see supra note 9 and accompanying text) that this is a kind of reasoned persuasion, not rational persuasion? Not entirely. The dinner guest is motivated as a matter of rationality to address the intransitivity in her preferences. To this extent my argument begins with rational persuasion. But the particular resolution of the intransitivity according to a particular partitioning of, and path through, the intransitively ordered alternatives looks more like reasoned persuasion in that it appeals to the chooser's own situation and how she sees it. For an argument that reasons (as taken from the agent's point of view) must ultimately provide for what is normatively compelling in the requirements of rationality, see Niko Kolodny's account of "transparency" in "Why be Rational?" (2005) 114 Mind 509 at 557-560. This seems like a kindred idea to mine. However, it must be remembered that the normative requirements of rationality provide the subject matter of this account based (ultimately) on reasons. So I prefer to think of my account as providing a sort of hybrid view in the ongoing debate over the priority of reasons or rationality.
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persuasion activates in the two of us a kind of "thinking together". Under a jointly available conceptual scheme, we both go down a choice path to a result that can be rationally shared, despite the difference in our initial preferences. 16 In this section I have developed the idea of rational persuasion as a way of leading someone down a sensible and sensitive choice path. I have suggested that at the end of this choice path we can rationally agree, that is, we can resolve our social choice under shared reasons despite our differences in preferences. This suggests one of the more obvious ways that rational persuasion can effectively be used in social choice. But there is another. Just as the presence of shared reasons under some conceptually ordered choice path can effectively be used to order individual preferences that are in conflict, so too the absence of shared reasons can be used to undermine individual preferences that are shared. However, why this might be useful in social choice needs some spelling out. Why would it be helpful to destabilize agreement on preferences? This seems perverse. The next section of the paper offers an argument for why such destabilization may be helpful. I begin by showing how, in legal decision-making, the absence of shared reasons for a shared preference can render a group unpersuasive and, therefore, indecisive. I then show how this sort of rational discipline on shared preferences can be more generally useful in social choice.
16. In adjudicative processes the path of persuasion is more complicated and takes the form of claims, counterclaims, and defences as the litigants argue back and fonh towards a particular result. But an argument structured in this way exhibits the kind of collective rationality that is characteristic of path dependence. Each (subsequent) reply must address what is (sensibly) put at issue in some (prior) claim and, absent a reply, that prior unanswered claim will carry the day on that issue. To the extent that the litigants are answerable more to each other than they are to some independent truth in the world, the adjudicative result that they construct together comes closer to the requirements of (a shared or collective) rationality than the demands of (a third-personal) reason. For this argument in more detail, see Bruce Chapman, "Defeasible Rules and Interpersonal Accountability" in J. Ferrer & G.B. Ratti, eds., Essays in Legal Defeasibility (Oxford: Oxford University Press) [fonhcoming in 2010].
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II. Persuasion, Shared Reasons and Rational Social Choice In the opening sentence of Social Choice and Individual Values, Arrow identified two methods of making social choices within a capitalist democracy: "voting, typically used to make 'political' decisions, and the market mechanism, typically used to make 'economic' decisions."17 Although this opening sentence, and the impossible result that it foreshadowed, must have appeared broad in scope in 1951, it seems clear now that at least one method of making social choices is conspicuously absent. Law and legal decision-making is also a method for making social choices within a capitalist democracy. Yet Arrow only mentions law, and more specifically, "the rule of law", in a footnote to his first paragraph, and then only to suggest its affinity with the thoughtless inflexibility of a sacred code. IS There is some irony in this last point. If anything, thought and reasoning play more significant formal roles within legal decision-making than they do within the political or economic methods of making social choices that Arrow mentions. In politics, for example, while the final vote of a legislature may be preceded by much discussion and exchange of reasons, the authority of the vote is not affected by the quality of that discussion. Indeed, such discussion need not have occurred at all. And, in market transacting, so long as one has the property right in question, one need not justify or defend with reasons one's willingness or reluctance to trade. What makes a political vote or a market transaction ultimately authoritative is not the cogency of the actor's reasoning but simply the fact that these different acts of choosing have occurred within their proper jurisdiction. 19
17. Supra note 1 at 1. 18. Ibid. 19. There needs to be some qualification here, at least on the political side, for the proponents of epistemic democracy, that is, for those who argue that majoritarian democracy, under certain assumptions, might usefully track the truth of some moral claims. This is a view that, in turn, might usefully accommodate deliberation and reasoning within its processes. See e.g. David Estlund, "The Insularity of the Reasonable: Why Political Liberalism Must Admit the Truth" (1998) 108 Ethics 252.
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However, judicial law making or adjudication, at least within common law systems, would appear to be importantly different in this respect. In addition to providing a decision in response to some dispute, common law judges are expected to articulate a set of publicly comprehensible reasons in support of the outcome they deem correct. And the reasons so articulated form a large part of the authoritative basis for the decision. Weak or unpersuasive reasoning will undermine the authority of a case and leave it exposed to the indignity of being distinguished into oblivion, if not completely overruled or reversed. We can appreciate the more general significance of this difference in the legal approach to the social choice problem if we consider the following example. 20 Suppose that a plaintiff has been injured while using some product. Imagine that she has advanced two separate and independent claims for the recovery of damages from the defendant manufacturer. The plaintiff has argued that the product was either defectively manufactured (D) or sold with an inadequate warning (W), where either of these two arguments (and, let us also suppose, only one of these two arguments) would be sufficient, if successful, to win a judgment J for the damages in question. In symbols, we have (D or W) ~ J. Now suppose that a panel of three judges has considered the various arguments and that each judge has come out on the issues in the following way. Judge A believes that there is no reason for thinking that the product was defectively manufactured. Thus, he believes argument D to be false. But he thinks argument W is true; in other words, he thinks that, although the product has not been defectively manufactured, there is some risk and the consumer has not been adequately warned. Thus, he would find reason for J on the basis of W. Judge B, on the other hand, believes that, while adequate information has been provided and the argument W is therefore false, the product has nevertheless been defectively manufactured, and so argument D is true. Thus she too would find in favor of], albeit for a reason different from Judge A. Finally, Judge C rejects both arguments D and Was false, and therefore also rejects J as false. The views of the three different judges {each of whom accepts the
20. I have discussed this example at length in Bruce Chapman, "Rational Choice and Categorical Reason" (2003) 151 U. Pa. L. Rev. 1169 at 1190-94.
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general legal proposition (D or W) in Table 1.
+-+ ]))
are presented in summary form
Table 1: The Three Judges' Reasons 1. There should be J in this case for reason D.
2. There should be J in this case for reason W.
3. There should be J in this case for either reason D or reason
w. False True False False
Judge A Judge B Judge C Majority
Where:
True False False False
True True False True
J is the proposition "The plaintiff wins a judgment for damages." D is the proposition "The product was defectively manufactured." W is the proposition "There was an inadequate warning of product risks."
And:
(Dor W) ...... J
It should be apparent that, at the group level, there is something odd going on here. As we read the group level view across the last row in the table, we can see that a majority of the court rejects proposition 1, or the proposition "There should be ] in this case for reason D", as false. Further, we see that a majority of the court also rejects proposition 2, or the proposition "There should be] in this case for reason W', as false. Yet, a majority of the court accepts the disjunctive proposition 3, "There should be] in this case for either reason D or reason W', as true. In this combination of votes there is a kind of collective irrationality that is similar to what we see in the majority voting paradox conventionally used to illustrate Arrow's social choice problem. 21 The collective irrationality would become particularly apparent if the majority of judges A and B in column 3, who support an outcome favouring the plaintiff, had to articulate a set of publicly comprehensible reasons in support of that view. There are, by hypothesis, only two possible arguments that the plaintiff can make in this case to win an award for damages J. Yet, on each of these essential arguments, the two
21. For discussion of the majority voting paradox, see text accompanying note 25 below.
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judges have completely opposed views (as indicated by columns 1 and 2). The two judges may share a common preference, or brute predisposition, for the outcome favouring the plaintiff, but it is not at all clear that they have a shared understanding of what it is that they are doing to reach that outcome. 22 It is as if what they want to do together lacks any real common identity for them. They would, therefore, have some difficulty saying together what it is that they want to do together. In other words, they would have some trouble forming a persuasive majority. Nor is the problem merely that there is a plurality of reasons here, with no particular reason commanding majority support. There are majority views on each of the relevant reasons and they are that neither reason D nor reason W is a good reason for the plaintiff to prevail in this action. It is here, down columns 1 and 2 and not down column 3, that the majority's common understanding and power of persuasion can really be found. Now one might wonder whether this lack of common understanding of, or reason for, a shared preference for a particular legal outcome must translate into any practical difficulty for the majority actually to act on its preference. Does the fact that the members of the majority cannot articulate a common view of what it is that they are doing have any impact on the real possibility of choice? In some strictly causal sense, of course, there cannot be any such impact. It is always possible to pursue one's preferences without good reasons and always possible for a majority to pursue its preferences without any coherent reason across its members. Indeed, this was the contrast between legal and non-legal methods of social choice that I referred to at the beginning of this section. The preferred alternative is no less available as an opportunity for choice simply because the majority cannot organize its thinking in favor of that preferred result under a single (coherent) set of concepts or categories of thought. Thus, at first glance there may be little in this legal example that provides any reason for thinking that there must be a connection between what we can say or think (together) and what we
22. Of course, each judge has a reason for what he or she wants to do. To that extent the position of each judge is reasoned and not merely a matter of preference or brute predisposition. But as these reasons are not shared between the judges, what is shared, not being supported by reason, looks more like a mere preference or brute predisposition.
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can do (together). The conventions of rational social choice, at least in their most scientific or behaviourist garb, only require an observable consistency of choice across overlapping sets of alternatives (as in the usual revealed preference axioms), and do not seem to be much implicated by the presence or absence of any shared state of mind. Further, one can even imagine our plaintiff in the Table 1 example arguing that she should win a judgment J simply because there appears to be a majority agreement in favour of this outcome in column 3. She might concede that the majority has no common set of reasons for this result, but she will likely point to the fact that there appear to be no reasons supporting the majority judgments down columns 1 or 2 either. Why should a requirement that there be shared reasons in column 3 be used so arbitrarily to disadvantage her? A lawyer will be tempted to reply, of course, that the plaintiff's appeal to the level of agreement in column 3 is inadequate, because in law she is obliged to frame her claim against the defendant as an argument, that is, under some sort of conceptual structure. It will not do for the plaintiff to show only that each member of a majority of the judges believes (in some unstructured way) that the defendant owes her damages for some reason. Instead, she must show that (more probably than not) a majority of the judges believes that there is a reason-at least one particular reason-for her claim. It is in this respect that some claims, even if they are right (or right more probably than not once we "add up" the independent probabilities that each of the different reasons might be true), may not be right for the right reasons. In other words, a lawyer will demand of the plaintiff that her claim be both right and rational. Still, in many situations calling for collective action, it seems likely that the individual members of a decisive majority will not have reasons in common for what they most want to do. Yet we will not feel that this is in any way problematic for them.23 Consider, for example, that most mundane of economic transactions, the purchase of a car.24 To give
23. See e.g. Lewis A. Kornhauser & Lawrence G. Sager, "The Many as One: Integrity and Group Choice in Paradoxical Cases" (2004) 32 Phil. & Pub. Affairs 249 at 256-58. 24. I have used this example in "Rational Choice and Categorical Reason", supra note 20 at 1196-99.
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this problem a collective dimension, imagine that there is a three-person purchasing consortium and that a majority of the consortium has voted to buy a white sports car. One member of the majority has voted this way only because the car is white and the other only because it is a sports car. Table 2 summarizes this scenario in a way that appears to make it fully analogous to the legal example laid out earlier in Table 1. Table 2: Reasons for Buying a Car
1. We should buy
2. We should buy
3. We should buy
this car because it is
this car because it is
this car because it is
white.
a sports car.
a white sports car.
1. Individual A
True
False
True
2. Individual B
False
True
True
3. Individual C
False
False
False
4. Majority
False
False
True
The fact that the members A and B of the majority in column 3 do not have reasons in common to support their shared preference for buying this particular car is not thought to present them with any real difficulty. Nor is it thought that rationality compels the purchasing consortium to choose not to buy this white sports car simply because a majority rejects both reasons for buying it: the idea of buying it because it is white, and the idea of buying it because it is a sports car. The decision to purchase a car, even (more particularly) a white sports car, is not essentially decomposable into two prior atomic propositions: Is it a sports car? Is it white? That underlying structure, while possibly a helpful guide to the purchasing decision, is not an essential part of the problem in the same way that the plaintiff's claim to damages in Table 1 needs to be grounded on a very particular account of transactional wrong. Rather, the purchasing consortium is out to purchase a car, perhaps even the best car that is available to it all things considered. But that judgment is ultimately made of the car and on the whole, not on a criterion-by-criterion (or column-by-column) basis. However, despite this structural difference in the two examples, there might be something useful in insisting on the greater rationality requirement inherent in the legal idea that members of a group can act
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sensibly together only if they can organize what they would prefer to do under a common understanding, that is, only if they can act together under a common set of categories or concepts. That this is sometimes difficult to do, and that it sometimes frustrates the achievement of shared preferences, might be precisely what is so useful about it. To illustrate this point, suppose that the three individuals in our car purchasing consortium originally had preferences over three alternative cars as follows (where for each individual the alternatives are preferred in order from top to bottom within each column): Table 3: Car Preferences Individual A
Individual B
Individual C
White sports car (WS)
Black sports car (BS)
Black family car (BF)
Black family car (BF)
White sports car (WS)
Black sportS car (BS)
Black sports car (BS)
Black family car (BF)
White sports car (WS)
This preference profile makes sense of the individual judgments offered by each individual in Table 2. It is also, of course, the preference profile that makes for the familiar majority voting paradox. 25 A majority prefers WS to BF, BF to BS, and BS to WS. Thus, within the social choice framework, there is the danger here of a kind of excess of rational doing: for every alternative that the consortium is tempted to choose according to its majoritarian preferences, there is another that a majority would prefer to have instead. It is this excess of rational doing that gives rise to cycling and instability. Now it is common for economists to point out that the problem here is that individual preferences are not "single peaked", that is, that
25. For a good introductory discussion of the majority voting paradox, see Dennis Mueller, Public Choice III (Cambridge: Cambridge University Press, 2003) at 84-85. It is easy to prove that, if a majority voting paradox is to occur, the problematic preference profile as exemplified here (sometimes called a "Latin Square" where, for some triple of alternatives, each of the three alternatives appears at least once as a "best" alternative, as a "worst" alternative, and as a "between" alternative in that triple for at least one individual) must be present somewhere in the population of voters. For a proof, see Robert Sugden, The Political Economy 0/ Public Choice (Oxford: Martin Robertson, 1981) at 157-58.
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there is no general agreement (1) that all the alternatives are to be assessed according to some single decisive dimension and (2) that one of the alternatives is of intermediate value on that decisive dimension. If only that were so, the argument goes, then that intermediately placed alternative would never be a worst alternative for any voter and the majority voting paradox would never occur. 26 This is, in effect, to insist that individuals organize their preferences in a single-minded way along one decisive dimension and to allow them only the limited scope of ordering the social alternatives according to how these alternatives vary quantitatively (more or less) along that decisive dimension. 27 But, as the example suggests, and as multidimensional models show more generally,2s individuals react, reasonably, to a broad range of categorically different dimensions or aspects of the social alternatives on offer. And so the question arises whether these different and plural dimensions of a social choice problem can be rationally organized in some way so that instability can be avoided.
26. Mueller, ibid., at 85-86. If there is this sort of agreement across the voters, and preferences are single-peaked, then the alternative chosen under majority rule will be that one which possesses that amount of the decisive dimension which is most preferred by the median voter, that is, the voter who is in the middle of the distribution of voters ordered along the decisive dimension according to where their most preferred alternative is on that decisive dimension. Why this alternative would be chosen in a series of pairwise choices over the available alternatives, and why no other alternative would defeat it under majority rule, can easily be appreciated in the following way: Imagine beginning at the extreme left (or right) of the decisive continuum. Then any move to the right (or left) will receive the support of a majority of the voters until we arrive at the median voter's ideal position on the continuum, at which point any further move to the right (or left) will be defeated by a majority of the voters. 27. The standard example is the ordering of candidates for political office from "left" to "right" on the ideological spectrum. Other examples might be the different quantities of some uni-dimensional public good (e.g. some amount of national defence expenditure) that different voters want to buy at a given tax price. 28. See Richard D. McKelvey, "Intransitivities in Multidimensional Voting Models and Some Implications for Agenda Control" (1976) 12 J. Econ. Theory 472. For discussion of the multidimensional case in a legal context, see Bruce Chapman, "More Easily Done Than Said: Rules, Reasons and Rational Choice" (1998) 18 Oxford J. Legal Stud. 293 at 300-16.
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The car example is suggestive. The majority coalition of A and C can say together (in support of what they might do together), "Given that the car is black, we would prefer it to be a family car." Likewise, the majority coalition of Band C might be able to say, "Given that it's a sports car, we would prefer it to be black." In this respect, these coalitions can use what are sometimes referred to as generic preferences. 29 But what would the majority coalition A and B say together? In some sense, of course, they have a shared preference over a pair of particular alternatives just like the other two majority coalitions do. Indeed, as already intimated, that is what gives rise to the instability. But their shared preference for WS over BF lacks any of the generic structure that characterizes the shared preferences of the other two majority coalitions. Thus, it is harder for them to articulate their shared preference in any sort of categorical way, that is, in a way that makes use of the generic preferences that are in play in the choice problem. In this respect they (as a coalition) are rendered "speechless" and unpersuasive, just like judges A and B were in the Table 1 legal example. But now we can see that there may be some stabilizing effect in using the discipline of a shared (or public) categorical reason to restrict the formation of this majority group or, at least, to restrict the persuasive impact of their shared preferences. After all, without this additional discipline and structure, there is only a senseless (i.e., non-categorical, non-conceptual) aggregation of (merely particular) preferences and the cycling problem that this permits. The discipline that is provided by an obligation to persuade, or offer reasons, under a system of (publicly intelligible) categories or concepts can be related more generally to a particular form of "value restriction" (specifically, "not-between value restriction") that Amartya Sen has shown is sufficient for avoiding the majority voting paradox. Specifically, if all individuals agree that in any triple a given alternative is "not between" the other two, that is, it is either the best or the worst of the three, then the majority voting paradox cannot occur.30 For 29. See Jon Doyle & Richmond H. Thomason, "Background to Qualitative Decision Theory" (1999) AI Magazine 55 at 58. 30. Amartya Sen, "A Possibility Theorem on Majority Decisions" (1966) 34 Econometrica 491. Compare supra note 25: If the problematic Latin Square preference
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instance, in the car example, it is easy to see that what A and C have in common is their view that WS is a "not-between" alternative for them. The real issue between them is whether or not the purchased car should be black (BF, BS) or white (WS). Individual A puts the white car alternative (WS) first and the pair of black car alternatives (BF, BS) last, whereas individual C does the reverse. This issue of colour is something that they can see themselves as deciding first (i.e. deciding over the two partitions {(WS) or (BF, BS)}), before they go on to decide, if necessary, what is to them a secondary issue, namely, what type of black car they should choose (i.e. deciding within the partition (BF, BS)).31 Likewise, what the coalition of Band C has in common might be expressed as an agreement over BF as a "not between" alternative, the sort of agreement that asks each to decide first whether the car chosen should be a sports car or not (i.e. over the two partitions {(BS, WS) or (Bf)}) and, only second, if it should be a sports car, whether it should be black or white (i.e. the issue within the partition (BS, WS)). But, again, the pair of individuals A and B would have difficulty articulating their own version of a common understanding of the relevant issues in this way. They agree between them that BS is a "notbetween" alternative, but what, exactly, is the category or concept that
profile is a necessary condition for the majority voting paradox to occur, then a sufficient condition for avoiding the paradox is to avoid the Latin Square. One method for achieving this sort of consensus is to have all voters agree that one alternative in every triple is "not between" the other two; it must stand apart as either better or worse. Another method, preferred by the economist (by way of the "single peaked preferences" condition), is to require the voters to agree on a "not worst" alternative in every triple; this might be the intermediately placed alternative on some judgement continuum that all voters consider decisive (e.g. the moderate candidate on a left·right political spectrum). As suggested in the text at notes 26 and 27, the latter offers a more quantitative ("more and less") approach to the problem; the former is more qualitative or categorical. 31. It could be, of course, that A feels there is a great deal more at stake in the choice of car type than the choice of colour, viz., that the preferential distance between BF and BS is large compared to the preferential distance between WS and BF. But this cannot be a view that he has in common with C. For C the preferential distance between BF and BS is contained within the distance between BF and WS. So the search for a shared categorical reason for choice, at least one linking A and C, cannot be found here. As the text following this note suggests, this suggested interpretation (that car type is a more important issue than car colour) is better for the pair of voters Band C.
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embraces the partition (WS, BF) of alternatives that is the complement to that not-between alternative? The problem, again, is that it is hard to "make sense" of such a partition of the alternatives in terms of the categories or concepts (colour and type of car) that are in play in the example. We might say, as we can for all the other possible pairs of individuals, that these individuals A and B agree at the level ofpreferences, but that they do not share any sort of categorical agreement about the sorts of issues that inform their choice and the order in which these issues might be considered. Without this they are unable to articulate the nature of their agreement. They are, in short, unpersuasive on the issues that appear to be at stake in the choice. Now one might object that the imposition of a categorical discipline on preferences still leaves too much unresolved to be helpful. After all, even those two groups of voters, A C and BC, which (unlike group AB) agree that the salient issues are the type and colour of the car to be purchased, disagree fundamentally on the order in which these two issues should be addressed. For group AC the most salient issue is colour; only after considering that issue would this group turn its attention, if necessary, to what type of car it should be. But for the group BCthe most important issue is type of car, and only if a sports car is chosen would the group turn its attention to the issue of colour. Moreover, the order in which these two issues are considered is likely to affect the outcome; in this respect we still do not seem to have escaped an arbitrary version of the problem of path dependent choice. For example, if colour is considered first, then it seems less likely that BS will end up being chosen. Individual C will choose in favour of black cars, and individual A against black cars, in the first round. Whether black cars are chosen categorically in that round depends a good deal on how individual B, whose preferences are not categorical in this way (i.e. they do not satisfy not-between value restriction on alternative WS), actually votes. But, in the event of a first round vote for a black car, it does seem likely that BF will defeat BS in the vote on the issue of type of car. An analogous argument would suggest that WS is the less likely choice if the issue of type of car is decided first. However, in some contexts there is good reason to think that this sort of path dependence can be made less arbitrary if social choice, and the individual preferences that give rise to it, are encouraged to be
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categorically sensitive as well as categorically sensible. This is a lesson we learned, more in the context of individual choice, from our earlier dinner party example. To see it in a social choice context, consider the example of a criminal trial. There are three possible outcomes: finding the accused innocent (outcome I), finding the accused guilty and imposing a severe sentence (outcome GS), and finding the accused guilty and imposing a lenient sentence (outcome GL). One can imagine three judges with the preferences over these three outcomes as shown in Table 4, a preference profile that would generate a majority voting paradox if it were not procedurally controlled. Table 4: Judges' Preferences A
B
C
I
GS GL
GL
I
GS
GS GL
I
Judge A believes that the accused did not commit the crime, but if the court holds that he did, then Judge A thinks that he should receive a severe rather than a lenient sentence as an appropriate punishment for it. Hence, Judge A prefers 1 to GS to GL. Judge B, on the other hand, believes the accused did commit the crime and agrees with Judge A that a severe rather than lenient sentence is appropriate. Thus, Judge B prefers GS to GL to I. Finally, Judge C is in some doubt as to whether the accused did commit the crime and is reluctant, therefore, to impose a severe punishment. On the other hand, given her doubts about the matter, she is also reluctant to let the accused off altogether. Thus, she prefers GL to 1 to GS. Now there does seem to be a natural partitioning of these alternative outcomes into two salient issues, Verdict (generating the choice over the partition {{I) or (GS, GL)}) and Sentence (generating the choice within the partition (GS, GL)). This is a partitioning that would "make sense" in a way that the alternative partitions, {{GS) or {I, GLn or {(GL) or (I, GS)}, would not. (What single concept, category, or issue sensibly comprehends the partition (I, GS), for example?) But, still, it seems that one could take these two issues, and the partitions to which they lend sense, in order of either "Sentence first, verdict afterwards" or "Verdict
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first, sentence afterwards". The law adopts the second of the two possibilities (and the Queen at Alice's trial in Wonderland adopts the first3~, but is there any reason to do so? One answer, of course, is simple economy: why bother attending to the issue of sentencing until we know that the verdict decision makes it necessary? But the analysis provided here suggests a different answer. While both sequences respect the partition of the alternatives that makes most sense, only the path that has us consider the verdict first, or the one forcing the initial choice to be over the partition {(1) or (GS, GL)}, imposes any sort of not-between value restriction on the panel of judges. Under the verdict first sequence, each judge must order his or her preferences around the salient legal categories, deciding whether to put the alternative I as either better or worse than (but not between) the alternatives GS and GL. This is something that Judges A and B, but not Judge C, can easily do. On the other hand, the sentence first process, while paying a kind of lip service to the same set of issues, does not require all of the judges to order his or her preferences around those issues in the same substantive way. In particular, Judge C, who appears to be saying something like "Whether or not I would find him guilty of the offence depends on the sentence he would receive", would have no difficulty voting these preferences under the sentence first procedure, even though these preferences do not seem to show a categorical sensitivity to the issues that are salient in the case. (Her preference or concern over the sentencing alternatives seems to obliterate any real concern for a correct verdict, much like our earlier dinner guest might have allowed her concern for etiquette to obliterate her hedonistic concerns had she considered the fruits in the order "First (A, 0) and then (a, A)".) In this way there is, in the verdict first process but not in the sentence first process, some useful conceptual discipline on the preferences that judges can effectively bring to social choice. In particular, Judge C is forced to ask a more categorical sort of question
32. Lewis Carroll, Alice in Wonderland, ed. by Donald Norton, 1971) at 96.
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about the verdict, that is, to show the same sort of sensitivity to the issues in the case as does the law she personifies.)) Further, even though they are in deep disagreement over the issues, the two judges, A and B, can at least articulate their disagreement in a way that demonstrates how their shared preferences are sensitive to (and disciplined by) the legal issues. Each can say to the other "I disagree with you deeply about the verdict, but, given a guilty verdict, 1 agree with you about the sentence that is appropriate."34 But Judge C cannot generate the same sort of issue sensitive conversation with either of the other two judges, at least if the conversation is required to respect some form of not-between value restriction. With Judge A she must say something garbled like "I disagree with you deeply about a lenient sentence, but, given ... " Given what? Without an organizing concept or category for the set (J, GS), which forms the complement to the notbetween alternative GL over which the pair disagree, the two judges are rendered speechless and unpersuasive, much as were the judges in Table 1, and the car purchasers in Table 3. A similar problem would plague any similar attempt at conversation between Judges C and B. The obligation to be (categorically) conversant with another, in order to be
33. Requiring this sort of structure can, of course, tempt the judge to "nullify" a possible guilty verdict for fear of risking the worst (for her) possible sentencing outcome GS. Verdict nullification has attracted a good deal of critical comment (particularly in the United States where in jury trials there is the possibility of the death penalty). Juries are said to be charged with the responsibility of reaching a verdict within the law as explained by the trial judge; it is the task of the judge to determine the sentence. For members of the jury to worry about the sentence rather than the verdict, particularly if they think the accused has committed the offence in question, is thought by some to violate the rule of law. Whatever the merits of verdict nullification by juries, our analysis here, based on the stabilizing impact of imposing the categorical constraints of notbetween value restriction, offers an independent reason for supporting the verdict first procedure. 34. I do not mean to suggest that this is the only sensible way for these two judges to articulate a sensitive divide between them on the issues. They might have diametrically opposed preferences (that is, be opposed on all issues), but still (between them) satisfy not-between value restriction on alternative l. In this situation each would say to the other, "I disagree deeply with you on the verdict, and given a verdict of guilty, I disagree with you on the sentence as well." This sort of conversation still reflects the issues in a way that conversation with Judge C would not.
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persuasive, restricts the sensible choice path in this scenario to "Verdict first, sentence afterwards." The appropriate social choice is simply the one that results from this conversationally sensible and sensitive choice path.
Conclusion Under rational persuasion one person seeks to bring another over to his point of view in two steps. First, the persuader points to an inconsistency in the attitudes that some other person (whom he seeks to persuade) has over a set of propositions (even propositions about social preferences, as in "x is socially preferred to y"). This set of inconsistent propositions includes the proposition that is contested between them. Second, the persuader seeks the particular resolution of that inconsistency which has the other person changing her view on the contested proposition so that it accords with that of the persuader. However, it is not initially clear how the mere fact of a more general inconsistency at the first step of the persuasive argument can determine (without more) a particular resolution of that inconsistency at the second step. For example, it seems perfectly clear that we ought not to believe both p and not-po (It seems hard to deny this without simultaneously asserting it, since any denial presupposes the logic of non-contradiction for its very impact.) We can know this constraint (the argument goes) regardless of the content of p, that is, regardless of our actual situation. 35 But it is the very non-contingency or generality of the constraint, its pure rationality if you will, that also seems to prevent it 35. This is what fuels "rationalism", or the idea that it is the requirements of rationality which are fundamental, and reasons, if they are to be explained at all, must be explained in terms of these requirements. By contrast, "reasons fundamentalism" holds that reasons are fundamental, and that if the requirements of rationality are to be explained, they must be explained in terms of reasons. But on the latter view we seem to have this problem: if the requirements of rationality hold regardless of our actual situation, then how can they be explained by the reasons that seem to depend on (or vary with) our actual situation? While the particular can be hostage to the general, the general cannot be hostage to the particular. Much turns in this debate on whether the requirements of rationality really must have the wide scope, or generality, which is so often claimed for them. On this, see Broome, supra note 6, and Kolodny, supra note 15.
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from having any particular purchase on our situation, resolving the contradiction of beliefs one way rather than another. How could it, rationally, if the constraint holds regardless of the content of p? And yet without that more particular resolution, there is no rational persuasion towards a specific result either. It is as if the very generality of the power of rationality is in tension with the particularity that is required for effective persuasion. A purely rational persuasion would seem to be impossible. This is where our discussion of non-arbitrary path dependent choice is helpful. The inconsistency that informs the first step of a rationally persuasive argument is analogous to the irrationality that Arrow means to avoid by requiring collective rationality. But I have argued here that it is a mistake to seek to avoid this irrationality (or, at least, to avoid it categorically) and to avoid the path dependence that is made possible by it. Rather, one should (sometimes) embrace the irrationality as the first step in the process of rational persuasion and recognize that some paths to resolving this apparent irrationality, and to choosing some final outcome, simply "make more sense" than others. In this way the "irrationality" is not so ·much denied as admitted (in the first step) and then rationally ordered under sensible choice paths (in the second). We are rationally led, by sensible and sensitive conversation, down a particular choice path. To insist from the start on rationality as path independence is to miss a chance at this collectively rational solution to the problem of social choice.
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