The Nature of Rationality
Paper | 1994 | $31.95 / £21.95 | ISBN: 9780691020969
- 内容简介 · · · · · ·
《合理性的本质》一本出版于1993年。此书主要探讨人类理性选择及信仰的性 质，分析了日常生活中的行为准则问题。诺齐克基本上持一种自然主义的立场，综合理论决定论、生物学、心理学以及心灵哲学等各学科知识，认为人类这种独特的 能力是人类社会长期进化的结果。这本书出版后，得到了哲学界的普遍肯定与重视
作者简介 · · · · · ·罗伯特·诺奇克（Robert Nozick，1938-2002），美国哈佛大学哲学教授，20世纪70、80年代与罗尔斯齐名的政治哲学家，因其在《无政府、国家与乌托邦》 一书中对自由至上主义做辩护而为国内外学者广泛关注。主要著作有：《无政府、国家与包括邦》、《合理性的本质》、《反思生活》等。
目录 · · · · · ·致谢
Nozick has a unique place in the annals of rational choice theory: he
refuted it. Or so say I in my role as the last of the true Popperians.
That was back in 1969. But now the mature philosopher is out to turn the
theory into, not exactly a transcendental reality, but something
implanted deep in the minds of some, if not all, human beings who have
been sculpted by Darwinian evolution. This is an ideological book,
concluding with evolutionary premises implying a complacent vision in
which something like our present social order arose out of biological
facts. The book begins, innocently enough, with technical questions
about making reasonable choices. I’ll follow Nozick up that garden path,
which is wonderfully landscaped, fresh and fragrant. But I’m giving
warning now that I’m afraid of the ogres at the bottom of his garden.
Two principles form the pillars of the abstract analysis of rational choice theory. The first says that if one action has more desirable consequences than any other, no matter what happens now or in the future, then that’s the right thing to do. It is dominant, as they say in the rationality business. That doesn’t merely seem self-evident, it is self-evident, or so most readers will say to themselves. The second principle needs a little cultivation, for it is best put in terms of probabilities. In one version, when you are uncertain what will happen, you should perform the action that would be most rewarding on average, if you were presented with the same choice on many occasions. There are many ways to state this idea without recourse to averages; all use versions of a technical concept called ‘expected value’. This principle of maximising expectation may need qualification to allow, for example, for people who are averse to taking risks: it may seem better to keep what you have, rather than risk losing some of it even though in the long term you should end up better off. It seemed obvious that these two principles are mutually consistent; Nozick, however, showed that they aren’t when, long ago, he published a counter-example, a case in which the two contradict each other. He says that it was invented by a physicist, William Newcomb, but if one thinks of refutation as a public event, than all honour goes to Nozick. He showed exactly how the two principles come into conflict, and briskly swept away all easy solutions. It would take most of a column to state Newcomb’s paradox properly, so I won’t do it here (anyway it makes me slightly nauseous, as good antinomy should). You’ll have to go to the book, where Nozick once again displays his extraordinary skill at combining precision and a light touch.
I dare say there have been hundreds of published stabs at the problem, a good many of which have increased our understanding of rational decision. That is the point of paradoxes: harsh confrontation, painful rethinking, new speculation, trial and lots more error. No one has offered a solution that satisfies more than a handful of immediate cronies. Part of the trouble is that anyone who has any interest in rational choice theory wants both principles, dominance and maximising expectation. Most theorists want to ignore the issues. There may be an interesting group of examples of Newcombian situations (elegantly developed by Alan Gibbard and William Harper in another classic study), but it is not infectious. Most decision problems don’t catch even the germ of an inconsistency. For the logician, however, such monster-barring (to use a catchy phrase of the late Imre Lakatos) is not just a dishonest ‘don’t look now, avert your eyes’; it also prevents us from learning from conflict.
LettersVol. 16 No. 5 · 10 March 1994
From Robert NozickIn the last portion of a generally positive review of The Nature of Rationality (LRB, 27 January), Ian Hacking unaccountably puts forward four propositions of his own manufacture and tries to lay them off on me. These are: 1. If a trait distinguishes humans from animals, and if individuals vary in degree in this trait, then some individuals are closer to animality than others. 2. Some individuals are closer to animality than others. 3. A free-market society is biologically inevitable. 4. Whatever (adaptation) evolution produces is good. My book does not endorse these propositions or make the arguments that Hacking puts forward in his review: I do not assert these propositions, I do not believe them, I find them repugnant and I think they can be shown to be false. This letter’s primary aim is to distinguish Hacking’s arguments and voice from my own. I also hope to convince readers of Hacking that his theses are false and untenable.
In addition to false and misguided theses, Hacking also uses figures of speech and rhetoric to insinuate what he has no basis for asserting explicitly. I had speculated that rationality might be an evolutionary adaptation, and that just as individuals show biological variation in other traits that play a complementary role in social co-operation, they also might vary in the intensity of their capacity for rationality. Hacking writes that if rationality has degrees, it ‘turns out to be no more a human universal than skin pigment’. These are Hacking’s words, and this is Hacking’s analogy, carefully chosen to insinuate racism. Throughout my discussion I spoke of ‘variety among the members of a group’, never of differences between groups. My one mention of groups spoke of ‘cultures whose traditions are unreceptive to Weberian rationality’. Because, following Max Weber, I had spoken of one form of rationality as extending its sway in the world, Hacking also writes of rationality’s ‘biologically ordained mastery of the universe and its denizens’ – am I mistaken, or is this Nazi-like rhetoric?
Hacking’s first thesis is this. If rationality distinguishes people from animals, and if people differ in their degree of rationality, then it follows (and we must infer) that ‘some people are closer to animality than others.’ Let us call this Hacking’s Inference to Animality Thesis. Presumably this thesis is not only about rationality. If any trait distinguishes people from animals, and if people differ in degree along this trait, then Hacking would have us infer that ‘some people are closer to animality than others.’ Many writers have claimed that language is what distinguishes people from animals but, despite the fact that different individuals develop and use this linguistic capacity to different extents, to my knowledge no one other than Hacking has claimed that these writers said, believed or had to infer that some individuals are closer to being animals than others. Noam Chomsky emphasises that all human beings, very quickly, learn quite specific grammars from paltry data, and he speculates that there is a specialised biological basis for such learning. All humans possess this capacity to learn language yet Shakespeare and Joyce draw upon and extend the full resources of English, and they write sentences and lines that I could never aspire to write. Perhaps my difference from them is solely environmental, but I tend to doubt that had I been raised in their exact environment I would have their same literary skills. There may be a biological basis to differences among individuals in their capacities to use language or these differences may stem from complicated mixtures of biological and environmental factors. If language distinguishes human beings from animals, and human beings differ in their linguistic capacities, does it follow, as Hacking claims, that some individuals are closer to being animals than others?
The important gulf between humans and animals is this: all humans are able to learn and use a human language; no animals are. The large differences in linguistic ability among humans are relatively minor by comparison. All people have passed the significant threshold, and the variations do not put some individuals closer to those on the other side of the threshold. Suppose that ability to fly unaided is what distinguishes birds from other animals. Yet some birds fly more swiftly than others, and with greater dexterity, and some can fly higher. Still, the slower flyers are not more non-birdlike than their fellow birds; they are not closer to being cats. All are birds, equally birds, by virtue of being able to fly unaided. It doesn’t matter that they show different skills in flight.
Similarly for other human traits. Other writers think that not only consciousness but a capacity for self-consciousness is what distinguishes people from animals. It doesn’t follow that the rest of us are closer to being animals than are such acknowledged geniuses of self-consciousness as Montaigne, Henry James and Sigmund Freud.
All humans share a capacity for rationality. If we suppose that it is this capacity that distinguishes people from animals, still, the gulf that separates people from animals constitutes a threshold all people have crossed, compared to which the differences among individuals in their rationality are minor. If there are individuals whose capacity for rationality is less intense or less developed, they are not closer to animals, any more than are those whose linguistic capacity is less intense or less developed.
The writers who wished to distinguish people from animals were not seeking a biological definition, say in terms of number of chromosomes. They were looking for a valuable trait, one to compliment human beings with. With every proposed candidate for such a trait, and not just rationality, individuals show variation. Since I do not accept Hacking’s Inference to Animality thesis, I do not infer that some people are closer to animality than others. The question is whether Hacking himself can avoid this serious and monstrous error. There are only two ways: either Hacking must hold that the whole project of commending people by distinguishing them from animals is in error and is intrinsically objectionable, whatever trait it focuses upon, or Hacking must propose a valuable trait that serves this purpose on which individuals do not show any variation at all. However, Hacking does not follow either of these two ways in his review and since he does endorse the Inference to Animality Thesis, it appears, therefore, that Hacking does accept that conclusion that ‘some people are closer to animality than others’. On the other hand, I reject Hacking’s Inference to Animality Thesis, and I also reject its conclusion.
In my book, I was not, in fact, attempting to distinguish people from other existing animals, and I would not be distressed to learn that chimpanzees or dolphins or Alpha Centaurians had the capacity to be rational, self-conscious, use language etc. At the end of a book, a portion of which offered evolutionary speculations about rationality, I wrote: ‘Although our rationality is, initially, an evolved quality – the nature of rationality includes the Nature in it – it enables us to transform ourselves and hence transcend our status as mere animals.’ It has enabled all of us to do that.
In The Examined Life, I wrote that authors should take steps to guard against their ideas being distorted and misapplied. It is, of course, extremely difficult to anticipate the most heinous distortions. Racism is an abomination, a plague humanity has inflicted upon itself. It leads to horrors, it is false, and it morally corrupts those who see the world through its distorted lens. I thought it unnecessary to say anything this evident in the book, but I did speak of related more subtle matters. I criticised Thomas Sowell’s argument that discrimination against blacks in the United States is not very serious; I said that the even application of given standards is not enough to show non-discrimination, there also must be no bias in the selection of which standards to apply; and I used this distinction to criticise an often cited statistical argument that there was no discrimination against women in university graduate admissions (pages 103-104 and note 59). There could be no greater distortion of my book than what Hacking does: to enlist it to aid the racist and cognate arguments which Hacking makes or insinuates.
Hacking puts forward two other theses which are false, misguided, and nowhere proposed in my book. These theses hold that a free-market economy is biologically inevitable, and that whatever is biologically selected for is therefore good.
I reject the view that a free-market economy is biologically inevitable. First, even if rationality is a biological adaptation, there is no necessity that a society will be built around that particular biological trait rather than around some other one. Second, other modes of social organisation also utilise rationality – a free-market economy is relatively recent, after all. Third, a market economy makes special use of a particular form of rationality, Weberian rationality, but there is no biological necessity that a society will utilise that. Even if Weberian rationality most flourishes in a market economy, and even if there were a social-scientific law that says all societies must eventuate in ones where Weberian rationality most flourishes – I know of no such law – this would not make a market economy biologically inevitable.
While in The Nature of Rationality I did not discuss the relation of evolution to a market economy at all, I did explicitly reject Hacking’s Biological Inevitability Proposition in a previous book, The Examined Life, where I wrote (page 281):
Issues about human nature have tended to be discussed in terms of what traits or features are unalterable – for example, are people ineradicably possessive and self- and family-centred or (this seems to be the implicit alternative) is socialism possible? It seems more fruitful to consider how much energy society would have to expend to alter or diminish certain traits and how much energy to maintain modes of cultural socialisation that would avoid these traits. Innate human nature is best conceived not as a set of fixed outcomes but as a gradient of difficulty: here is how steep the price is for avoiding certain traits. So while human nature may not make certain social arrangements impossible, it may make them difficult to achieve and maintain.Biology does not determine market forms, much less make them inevitable. Although market society is not biologically inevitable, not every biological determination of a feature of society need be repugnant. Someone’s attitude towards biological determination, if it exists, will depend mainly upon an evaluation of the character of the determined feature in comparison to that of the excluded alternatives (unless that person’s vision of human autonomy demands – as mine does not – society’s complete freedom from any biological constraint).
I also reject Hacking’s proposition that whatever evolution produces is good. At the close of my speculation about an evolutionary explanation of the economist’s motivational assumption of wealth maximisation (an assumption economists apply to explain behaviour in all societies, market or not), based upon the (empirical) supposition that throughout most of human history, except for the past hundred and fifty years, wealthy people tended to reproduce more, producing more children who themselves lived to reproductive age, I wrote: ‘Are so few of us concerned with the higher things of life because those of our ancestors’ contemporaries who did care left fewer offspring and we are descended from those who tended to care about material possessions instead?’ (page 127). Hardly a lauding of whatever evolution might produce! (Nor could my detailed discussion of the technicalities of evolutionary fitness and function on pages 114-119 fit with an uncritical attitude towards evolution’s products.) The adulation of whatever evolution produces is absurd and, in some imaginable instances, evil.
When in the last few pages of The Nature of Rationality I turned from more technical reflections on rationality to consider its place and role in the modern world, I drew upon Max Weber to see rationality, in its Weberian form, as an enormously transformative force (of course, as embodied in people, their actions, and the institutions these form, not as some transcendent force). I wrote:
Rationality has reshaped the world. This is the great theme of Max Weber’s writing: economic and monetary calculation, bureaucratic rationalisation, general rules and procedures came to replace action based upon personal ties, and market relations were extended to new arenas. Rationality, together with related institutional changes that explicitly utilise and depend upon rationality, has brought many benefits and thus enabled rationality to extend its domain further.In these paragraphs I noted a powerful trend in the modern world, and I see a problem this presents. Does Hacking think it is not a powerful trend? Does he think it does not have serious consequences on individuals’ lives and presents no serious problem? It is ironic that the very paragraph where I thought I was pointing out a problem attendant upon the spread of capitalism with its Weberian rationality is the one Hacking uses to draw a conclusion celebrating – the words are Hacking’s, and are the last words of his review – ‘the most rational ones … [being] engaged in a biologically ordained mastery of the universe and its denizens’.
Yet this has made the world, in various ways, inhospitable to lesser degrees of rationality. Those cultures whose traditions are unreceptive to Weberian rationality have fared less well. Within Western societies, the balance has shifted in the division of traits that served in hunter-gatherer societies. Rationality first was able to extend its sway by bringing benefits to other traits too, but the other traits became more dependent upon rationality and rationality became more powerful and subject to fewer constraints. Rationality is proceeding now to remake the world to suit itself, altering not only its own environment but also that in which all other traits find themselves, extending the environment in which only it can fully flourish. In that environment, the marginal product of rationality increases, that of other traits diminishes; traits that once were of co-ordinate importance are placed in an inferior position. This presents a challenge to rationality’s compassion and to its imagination and ingenuity: can it devise a system in which those with other traits can live comfortably and flourish – with the opportunity to develop their rationality if they choose – and will it?
It is astounding that Hacking, a philosopher with some reputation as an intellectual historian, can think it legitimate to play so fast and loose with what an author says. I speak of individual differences within a group, Hacking introduces talk of ‘skin pigment’; I worry about the dominance of Weberian rationality, Hacking introduces talk of ‘biologically ordained mastery’. And Hacking closes by writing:
Just look at the extraordinary slide we see in this book. We pass from technical discussions of paradoxes and dilemmas within a rigorous formal theory, to a hypostasised entity, rationality, that is out there ‘extending its sway’ (swaying not the mind but the world order). This entity is biological, the product of evolutionary struggle. There is a stupendous is/ought move here. Rationality is – well – rational. It’s about right decision, reasonableness: that’s value. Evolution is where we have got to: that’s fact. So we have got to what’s right. We who have arrived at a free-market economy have not invented another of the varied cultural forms that so characterise the amazing creativity of our socially imaginative species. The present dominating cultural form is presented as inevitable, contingent only on the course of neo-Darwinian evolution itself.Where to begin? When I say that rationality changes the world, I, of course, mean that it is the continuing rational actions of individuals, and the ensuing institutional effects, that produce these changes, not some hypostasised entity. And I nowhere speak of evolutionary ‘struggle’. Hacking charges next that ‘there is a stupendous is/ought move here,’ in the book. It is difficult to reconstruct the steps of Hacking’s move, which exists only in his review, not in my book. The is starting point is the book’s hypothesis that rationality is an evolutionary adaptation. The supposed move to ought appears, from what Hacking writes, to have two major components: a step to rationality’s being valuable (because evolution produced it), and a step to a free-market society being biologically inevitable and hence valuable. Each step is muddled and I do not make either one. However, I do think that rationality is valuable; that is why I wrote a book on the subject. So evolution did produce something that also is valuable, but it is not valuable because evolution produced it – there is no is/ought move here. (I denied earlier the propositions that whatever evolution produces is good, and that a free market society is biologically inevitable.) I could examine closely Hacking’s presentation of the supposed first step to show how muddled it is. (There is less to examine in Hacking’s presentation of the second step about biological inevitability; he just asserts it.) However, there is no point to such close examination because Hacking wouldn’t deny that these two steps are muddled – that’s why he calls it a ‘slide’. But where does this slide take place? Where exactly does the book make this stupendous is/ought move? Nowhere but in Hacking’s mind. Five lines after his sentences quoted above, Hacking gives us his closing words about ‘the most rational ones … (being) engaged in a biologically ordained mastery of the universe and its denizens’.
How can Hacking have proceeded in this bizarre and irresponsible fashion? At one point he writes: ‘I’m worried that no reviewer I’ve come across – the book has been out for some time now – has mentioned this readily noticed inference’ (to the conclusion that some people are closer to animality than others). The reason no other reviewer of the book mentioned this is plain: it is just not there.
It is possible that even Hacking does not accept the Inference to Animality Thesis, for he says that its conclusion ‘appears to follow’. I don’t think it follows, and have shown that it doesn’t. If Hacking also doesn’t think it follows then his attempt to pin on me a conclusion that I don’t state via an inference that I don’t make and that he himself knows to be invalid is even more reprehensible.
I too would find offensive and repugnant a book fitting the description Hacking offers. To so describe The Nature of Rationality is a slanderous distortion. Hacking mixes my sentences with grotesque musings and inferences that are wholly his own contribution. It is loathsome that he fabricates, and seeks to attribute to me, theses which I condemn utterly.
Vol. 16 No. 6 · 24 March 1994
From Ian HackingThere is one important difference between Robert Nozick and myself (Letters, 10 March). He speculates that rationality might be an evolutionary adaptation. He calls it a ‘trait’. I think of it as cultural. I do not conceive of it as a trait at all (trait meaning ‘a genetically determined characteristic or condition’ – The American Heritage Dictionary of the English Language, third edition, 1992). Hence not only are the four theses that Nozick calls ‘Hacking’s theses’ not mine, but the first one, about traits, is also not in my opinion relevant. I cannot find any reason for holding that rationality, in the sense of the earlier parts of the book, can be an evolutionary adaptation – although I’m sure that only our species could develop that idea of rationality. It is a social product of a very powerful sort, admirably expounded by Nozick himself. But it is not a trait that individuals have in varying degrees. People in a society that values rationality may reason better or worse, by the current standards of that society, but one is not thereby more rational than another. Other communities may not value the same forms of rationality, at least in the very theoretical version favoured by Nozick. It is a group thing, as are all cultural artifacts, and Nozick is offering a sophisticated philosophical analysis of a concept of rationality expressed in a large and relatively homogeneous group to which both of us belong. There may be an underlying sense in which humans have a capacity to reason. Nozick’s rationality, however, is not something inherited but a particular social form that is acquired.
The differences between us matter – they are differences between a philosopher who feels closer to evolutionary biology and cognitive science, and another who feels closer to cultural anthropology. Because of the time-honoured Western connection between rationality and humanity, these differences have political and social meanings, and your readers need to see how things look from the two distinct perspectives. Hence although my review was, as Nozick notes, ‘generally positive’, I was critical at the end. I welcome his clarifications and the overall stance expressed in his letter.
University of Toronto