今天吃饭时，一位朋友给我讲了纪伯伦的《鲸鱼与蝴蝶》这个寓言故事，来说明一个人向另一个人传达思想是如何的不可能，故事是这样的：

　　一天黄昏，一个男子和一个妇女不期而遇地同坐一辆驿站马车旅行。他们以前见过面。
　　那男子是个诗人，他坐在那妇女的身边，设法讲故事给她消遣，有的故事是他自己创作的，有的可不是。
　　然而，就在他讲着故事的时候，那位夫人竟睡着了。接着，马车突然晃荡，那位夫人醒了，她说："我真欣赏你所描摹的约拿和鲸鱼的故事。"
　　诗人接口道："然而，夫人，我刚才在讲给你听的故事是我自己创作的，说的是一只蝴蝶和一朵白玫瑰花，以及它们怎样的彼此以礼相待。"

纪伯伦（Khalil Gibran）生于黎巴嫩，这个混杂了犹太、早期基督教、希腊、拜占庭、阿拉伯、十字军、奥斯曼、亚美尼亚、近代英法殖民、泛阿拉伯社会主义、伊斯兰原教旨主义等等等等的神奇之地，不难想像，其对思想隔阂的体会何等深切，他说：“除非我们把语言减少到七个字，我们将永不会互相了解。”

这个故事，如果让波普（Karl Popper）来讲，我想他大概会这样说：“观念无法在两个第二世界（World Two）之间复制。”

波普用第一世界（World One，注意，大写）来指称我们的观念对之而形成的、但不依赖我们的观念而存在的、所谓自在的世界；休谟指出，我们永远无法证实这个第一世界的存在（当然，休谟没有活到300岁来使用第一世界这个词）；波普说，争论第一世界是否存在是无聊的（果然，波普之后，哲学家们不再争论这个无聊话题了）；然后，波普用第二世界来指称每个人对果真存在或他以为存在的第一世界所形成的观念，当然，有几个人就有几个第二世界。

波普认为（他老人家在天之灵大概会允许我做适度发挥），第二世界们之间固然千差万别，试图把它们变成一样，是徒劳的，当然，也是极其无聊的；重要的是，第二世界之间的互动会产生一个第三世界（World Three）；这个世界的奇特在于，在微观上，它依赖于个体观念而存在，但在宏观上，它与个体观念的存在无关；可以这样理解这一点：水波的存在微观上依赖于每个水分子的运动，但其宏观性质却与水分子个体运动无关。

比如，两位科学家各自提出一个命题，他们内心对这两个命题的理解可能大不相同，也就是说，他们都误解了对方的意思，但这无关紧要，只要这两个命题能共存于一个自洽的形式系统内，并且，按该形式系统的内在逻辑，能从它们演绎出其它东西，那么，虽然他们各怀鬼胎，却在为构造同一个第三世界而做出贡献。第三世界并不会因某个人的死去而消失，对于个体们来说，它是“自在的”，波普把它所包含的内容叫做“客观知识”（Objective Knowledge）。

科学的独特之处在于（与其他观念系统相比），它为第二世界之间的互动提供了一套规范，使得这些互动可能产生一个稳定且不断增长的第三世界，我称之为“可积累的知识系统”。

体会总结：不必介意观念间的差异，不必介意误读和曲解，你或许能“干扰”对方的认知过程，但别指望把自己的观念投影到他的头脑里；人们永远不会停止争辩（在宇宙毁灭之前），重要的是，不要让争辩永远停留在原地（看看国内的所谓社会科学吧）。

我最初对自由意志这个问题发生兴趣是在看约翰·埃克尔斯的《脑的进化：自我意识的创生》时，去年，Matt Ridley的Genome: the autobiography of a species in 23 chapters（《基因组：一个物种的23章自传》）一书再次激起我的兴趣，该书第22章谈论了这个问题，新浪读书上有该书的节译本，其中包括了第22章的译文。下面是该章原文：（注：关于“休谟之叉”一词究竟指什么，好像有不同说法，所以我暂时放弃这一术语）

CHROMOSOME 2 2  Free Will

Hume's fork: Either our actions are determined, in which case we are not responsible for them, or they are the result of random events, in which case we are not responsible for them.
                     Oxford Dictionary of Philosophy

As this book is being completed, a few months before the end of a millennium, there comes news of a momentous announcement. At the Sanger Centre, near Cambridge - the laboratory which leads the world in reading the human genome - the complete sequence of chromosome 22 is finished. All 15.5 million 'words' (or so - the exact length depends on the repeat sequences, which vary greatly) in the twenty-second chapter of the human autobiography have been read and written down in English letters: 47 million As, Cs, Gs and Ts.

Near the tip of the long arm of chromosome 22 there lies a massive and complicated gene, pregnant with significance, known as HFW. It has fourteen exons, which together spell out a text more than 6,000 letters long. That text is severely edited after tran­scription by the strange process of RNA splicing to produce a highly complicated protein that is expressed only in a small part of the prefrontal cortex of the brain. The function of the protein is, generalising horribly, to endow human beings with free will. Without HFW, we would have no free will.

The preceding paragraph is fictional. There is no HFW gene on chromosome 22 nor on any other. After twenty-two chapters of relentless truth, I just felt like deceiving you. I cracked under the strain of being a non-fiction writer and could no longer resist the temptation to make something up.

But who am 'I'? The I who, overcome by a silly impulse, decided to write a fictional paragraph? I am a biological creature put together by my genes. They prescribed my shape, gave me five fingers on each hand and thirty-two teeth in my mouth, laid down my capacity for language, and defined about half of my intellectual capacity. When I remember something, it is they that do it for me, switching on the CREB system to store the memory. They built me a brain and delegated responsibility for day-to-day duties to it. They also gave me the distinct impression that I am free to make up my own mind about how to behave. Simple introspection tells me there is nothing that I cannot help myself doing. There is equally nothing that says that I must do one thing and not something else. I am quite capable of jumping in my car and driving to Edinburgh right now and for no other reason than that I want to, or of making up a whole paragraph of fiction. I am a free agent, equipped with free will.

Where did this free will come from? It plainly could not have come from my genes, or else it would not be free will. The answer, according to many, is that it came from society, culture and nurture. According to this reasoning, freedom equals the parts of our natures not determined by our genes, a sort of flower that blooms after our genes have done their tyrannical worst. We can rise above our genetic determinism and grasp that mystic flower, freedom.

There has been a long tradition among a certain kind of science writer to say that the world of biology is divided into people who believe in genetic determinism and people who believe in freedom. Yet these same writers have rejected genetic determinism only by establishing other forms of biological determinism in its place - the determinism of parental influence or social conditioning. It is odd that so many writers who defend human dignity against the tyranny of our genes seem happy to accept the tyranny of our surroundings. I was once criticised in print for allegedly saying (which I had not) that all behaviour is genetically determined. The writer went on to give an example of how behaviour was not genetic: it was well known that child abusers were generally abused themselves as children and this was the cause of their later behaviour. It did not seem to occur to him that this was just as deterministic and a far more heartless and prejudicial condemnation of people who had suffered enough than anything I had said. He was arguing that the children of child abusers were likely to become child abusers and there was little they could do about it. It did not occur to him that he was applying a double standard: demanding rigorous proof for genetic explanations of behaviour while easily accepting social ones.

The crude distinction between genes as implacable programmers of a Calvinist predestination and the environment as the home of liberal free will is a fallacy. One of the most powerful environmental sculptors of character and ability is the sum of conditions in the womb, about which you can do nothing. As I argued in the chapter on chromosome 6, some of the genes for intellectual ability are probably genes for appetite rather than aptitude: they set their pos­sessor on a course of willing learning. The same result can be achieved by an inspiring teacher. Nature, in other words, can be much more malleable than nurture.

Aldous Huxley's Brave new world, written at the height of eugenic enthusiasm in the 1920s, presents a terrifying world of uniform, coerced control in which there is no individuality. Each person meekly and willingly accepts his or her place in a caste system - alphas to epsilons - and obediently does the tasks and enjoys the recreations that society expects of him or her. The very phrase 'brave new world' has come to mean such a dystopia brought into being by central control and advanced science working hand­in-hand.

It therefore comes as something of a surprise to read the book and discover that there is virtually nothing about eugenics in it. Alphas and epsilons are not bred, but are produced by chemical adjustment in artificial wombs followed by Pavlovian conditioning and brainwashing, then sustained in adulthood by opiate-like drugs. In other words, this dystopia owes nothing to nature and everything to nurture. It is an environmental, not a genetic, hell. Everybody's fate is determined, but by their controlled environment, not their genes. It is indeed biological determinism, but not genetic determin­ism. Aldous Huxley's genius was to recognise how hellish a world in which nurture prevailed would actually be. Indeed, it is hard to tell whether the extreme genetic determinists who ruled Germany in the 1930s caused more suffering than the extreme environmental determinists who ruled Russia at the same time. All we can be sure of is that both extremes were horrible.

Fortunately we are spectacularly resistant to brainwashing. No matter how hard their parents or their politicians tell them that smoking is bad for them, young people still take it up. Indeed, it is precisely because grown-ups lecture them about it that it seems so appealing. We are genetically endowed with a tendency to be bloody-minded towards authority, especially in our teens, to guard our own innate character against dictators, teachers, abusing step­parents or government advertising campaigns.

Besides, we now know that virtually all the evidence purporting to show how parental influences shape our character is deeply flawed. There is indeed a correlation between abusing children and having been abused as a child, but it can be entirely accounted for by inherited personality traits. The children of abusers inherit their persecutor's characteristics. Properly controlled for this effect, studies leave no room for nurture determinism at all. The step­children of abusers, for instance, do not become abusers.1
The same, remarkably, is true of virtually every standard social nostrum you have ever heard. Criminals rear criminals. Divorcees rear divorcers. Problem parents rear problem children. Obese parents rear obese children. Having subscribed to all of these assertions during a long career of writing psychology textbooks, Judith Rich Harris suddenly began questioning them a few years ago. What she discovered appalled her. Because virtually no studies had controlled for heritability, there was no proof of causation at all in any study. Not even lip service was being paid to this omission: correlation was being routinely presented as causation. Yet in each case, from behaviour genetics studies, there was new, strong evi­dence against what Rich Harris calls 'the nurture assumption'. Studies of the divorce rate of twins, for example, reveal that genetics accounts for about half of the variation in divorce rate, non-shared environmental factors for another half and shared home environ­ment for nothing at all.1 In other words, you are no more likely to divorce if reared in a broken home than the average - unless your biological parents divorced. Studies of criminal records of adoptees in Denmark revealed a strong correlation with the criminal record of the biological parent and a very small correlation with the criminal record of the adopting parent — and even that vanished when con­trolled for peer-group effects, whereby the adopting parents were found to live in more, or less, criminal neighbourhoods according to whether they themselves were criminals.

Indeed, it is now clear that children probably have more non­genetic effect on parents than vice versa. As I argued in the chapter on chromosomes X and Y, it used to be conventional wisdom that distant fathers and over-protective mothers turn sons gay. It is now considered much more likely to be the reverse: perceiving that a son is not fully interested in masculine concerns, the father retreats; the mother compensates by being overprotective. Likewise, it is true that autistic children often have cold mothers; but this is an effect, not a cause: the mother, exhausted and dispirited by years of unre­warding attempts to break through to an autistic child, eventually gives up trying.

Rich Harris has systematically demolished the dogma that has lain, unchallenged, beneath twentieth-century social science: the assump­tion that parents shape the personality and culture of their children. In Sigmund Freud's psychology, John Watson's behaviourism and Margaret Mead's anthropology, nurture-determinism by parents was never tested, only assumed. Yet the evidence, from twin studies, from the children of immigrants and from adoption studies, is now staring us in the face: people get their personalities from their genes and from their peers, not from their parents.1

In the 1970s, after the publication of E .O. Wilson's book Sociobiol­ogy, there was a vigorous counter-attack against the idea of genetic influences on behaviour led by Wilson's Harvard colleagues, Richard Lewontin and Stephen Jay Gould. Their favourite slogan, used as a tide for one of Lewontin's books, was uncompromisingly dogmatic: 'Not in our genes!' It was at the time still just a plausible hypothesis to assert that genetic influences on behaviour were slight or non­existent. After twenty-five years of studies in behavioural genetics, that view is no longer tenable. Genes do influence behaviour.
Yet even after these discoveries, environment is still massively important - probably in total more important than genes in nearly all behaviours. But a remarkably small part in environmental influ­ence is played by parental influence. This is not to deny that parents matter, or that children could do without them. Indeed, as Rich Harris observes, it is absurd to argue otherwise. Parents shape the home environment and a happy home environment is a good thing in its own right. You do not have to believe that happiness determines personality to agree that it is a good thing to have. But children do not seem to let the home environment influence their personality outside the home, nor to let it influence their personality in later life as an adult. Rich Harris makes the vital observation that we all keep the public and private zones of our lives separate and we do not necessarily take the lessons or the personality from one to the other. We easily 'code-switch' between them. Thus we acquire the language (in the case of immigrants) or accent of our peers, not our parents, for use in the rest of our lives. Culture is transmitted autonomously from each children's peer group to the next and not from parent to child - which is why, for example, the move towards greater adult sexual equality has had zero effect on willing sexual segregation in the playground. As every parent knows, children prefer to imitate peers than parents. Psychology, like sociology and anthropology, has been dominated by those with a strong antipathy to genetic explanations; it can no longer sustain such ignorance.2
My point is not to rehearse the nature-nurture debate, which I explored in the chapter on chromosome 6, but to draw attention to the fact that even if the nurture assumption had proved true, it would not have reduced determinism one iota. As it is, by stressing the powerful influence that conformity to a peer group can have on personality, Rich Harris lays bare just how much more alarming social determinism is than genetic. It is brainwashing. Far from leaving room for free will, it rather diminishes it. A child who expresses her own (partly genetic) personality in defiance of her parents' or her siblings' pressures is at least obeying endogenous causality, not somebody else's.

So there is no escape from determinism by appealing to socialisa­tion. Either effects have causes or they do not. If I am timid because of something that happened to me when I was young, that event is no less deterministic than a gene for timidity. The greater mistake is not to equate determinism with genes, but to mistake determinism for inevitability. Said the three authors of Not in our genes, Steven Rose, Leon Kamin and Richard Lewontin, 'To the biological determinists the old credo "You can't change human nature" is the alpha and omega of the human condition.' But this equation - determinism equals fatalism — is so well understood to be a fallacy that it is hard to find the straw men that the three critics indict.3
The reason the equation of determinism with fatalism is a fallacy is as follows. Suppose you are ill, but you reason that there is no point in calling the doctor because either you will recover, or you won't: in either case, a doctor is superfluous. But this overlooks the possibility that your recovery or lack thereof could be caused by your calling the doctor, or failure to do so. It follows that determin­ism implies nothing about what you can or cannot do. Determinism looks backwards to the causes of the present state, not forward to the consequences.

Yet the myth persists that genetic determinism is a more implac­able kind of fate than social determinism. As James Watson has put it, 'We talk about gene therapy as if it can change someone's fate, but you can also change someone's fate if you pay off their credit card.' The whole point of genetic knowledge is to remedy genetic defects with (mostly non-genetic) interventions. Far from the dis­coveries of genetic mutations leading to fatalism, I have already cited many examples where they have led to redoubled efforts to ameliorate their effects. As I pointed out in the chapter on chromo­some 6, when dyslexia was belatedly recognised as a real, and possibly genetic, condition, the response of parents, teachers and govern­ments was not fatalistic. Nobody said that because it was a genetic condition dyslexia was therefore incurable and from now on children diagnosed with dyslexia would be allowed to remain illiterate. Quite the reverse happened: remedial education for dyslexics was developed, with impressive results. Likewise, as I argued in the chapter on chromosome 11, even psychotherapists have found gen­etic explanations of shyness helpful in curing it. By reassuring shy people that their shyness is innate and 'real', it somehow helps them overcome it.
Nor does it make sense to argue that biological determinism threatens the case for political freedom. As Sam Brittan has argued, 'the opposite of freedom is coercion, not determinism.'4 We cherish political freedom because it allows us freedom of personal self­determination, not the other way around. Though we pay lip service to our love of free will, when the chips are down we cling to determinism to save us. In February 1994 an American named Stephen Mobley was convicted of the murder of a pizza-shop man­ager, John Collins, and sentenced to death. Appealing to have the sentence reduced to life imprisonment, his lawyers offered a genetic defence. Mobley came, they said, from a long pedigree of crooks and criminals. He probably killed Collins because his genes made him do it. 'He' was not responsible; he was a genetically determined automaton.

It to be thought that he had none. So does every criminal who uses the defence of insanity or diminished responsibility. So does every jealous spouse who uses the defence of temporary insanity or justifiable rage after murdering an unfaithful partner. So does the unfaithful partner when justifying the infidelity. So does every tycoon who uses the excuse of Alzheimer's disease when accused of fraud against his shareholders. So indeed does a child in the playground who says that his friend made him do it. So does each one of us when we willingly go along with a subtle suggestion from the therapist that we should blame our parents for our present unhappiness. So does a politician who blames social conditions for the crime rate in an area. So does an economist when he asserts that consumers are utility maximisers. So does a biographer when he tries to explain how his subject's character was forged by formative experiences. So does everybody who consults a horoscope. In every case there is a willing, happy and grateful embracing of determinism. Far from loving free will, we seem to be a species that positively leaps to surrender it whenever we can.5

Full responsibility for one's actions is a necessary fiction without which the law would flounder, but it is a fiction all the same. To the extent that you act in character you are responsible for your actions; yet acting in character is merely expressing the many deter­minisms that caused your character. David Hume found himself impaled on this dilemma, subsequently named Hume's fork. Either our actions are determined, in which case we are not responsible for them, or they are random, in which case we are not responsible for them. In either case, common sense is outraged and society impossible to organise.

Christianity has wrestled with these issues for two millennia and theologians of other stripes for much longer. God, almost by defin­ition, seems to deny free will or He would not be omnipotent. Yet Christianity in particular has striven to preserve a concept of free will because, without it, human beings cannot be held accountable for their actions. Without accountability, sin is a mockery and Hell a damnable injustice from a just God. The modern Christian consensus is that God has implanted free will in us, so that we have a choice of living virtuously or in sin.

Several prominent evolutionary biologists have recently argued that religious belief is an expression of a universal human instinct — that there is in some sense a group of genes for believing in God or gods. (One neuroscientist even claims to have found a dedicated neural module in the temporal lobes of the brain that is bigger or more active in religious believers; hyper-religiosity is a feature of some types of temporal-lobe epilepsy.) A religious instinct may be no more than a by-product of an instinctive superstition to assume that all events, even thunderstorms, have wilful causes. Such a super­stition could have been useful in the Stone Age. When a boulder rolls down the hill and nearly crushes you, it is less dangerous to subscribe to the conspiracy theory that it was pushed by somebody than to assume it was an accident. Our very language is larded with intentionality. I wrote earlier that my genes built me and delegated responsibility to my brain. My genes did nothing of the sort. It all just happened.

E. O. Wilson even argues, in his book Consilience,6 that morality is the codified expression of our instincts, and that what is right is indeed - despite the naturalistic fallacy — derived from what comes naturally. This leads to the paradoxical conclusion that belief in a god, being natural, is therefore correct. Yet Wilson himself was reared a devout Baptist and is now an agnostic, so he has rebelled against a deterministic instinct. Likewise, Steven Pinker, by remaining childless while subscribing to the theory of the selfish gene, has told his selfish genes to 'go jump in a lake'.

So even determinists can escape determinism. We have a paradox. Unless our behaviour is random, then it is determined. If it is determined, then it is not free. And yet we feel, and demonstrably are, free. Charles Darwin described free will as a delusion caused by our inability to analyse our own motives. Modern Darwinists such as Robert Trivers have even argued that deceiving ourselves about such matters is itself an evolved adaptation. Pinker has called free will 'an idealisation of human beings that makes the ethics game playable'. The writer Rita Carter calls it an illusion hard-wired into the mind. The philosopher Tony Ingram calls free will something that we assume other people have — we seem to have an inbuilt bias to ascribe free will to everybody and everything about us, from recalcitrant outboard motors to recalcitrant children equipped with our genes.

I would like to think that we can get a little closer to resolving the paradox than that. Recall that, when discussing chromosome 10, I described how the stress response consists of genes at the whim of the social environment, not vice versa. If genes can affect behaviour and behaviour can affect genes, then the causality is circu­lar. And in a system of circular feedbacks, hugely unpredictable results can follow from simple deterministic processes.

This kind of notion goes under the name of chaos theory. Much as I hate to admit it, the physicists have got there first. Pierre-Simon de LaPlace, the great French mathematician of the eighteenth cen­tury, once mused that if, as a good Newtonian, he could know the positions and the motions of every atom in the universe, he could predict the future. Or rather, he suspected that he could not know the future, but he wondered why not. It is fashionable to say that the answer lies at the subatomic level, where we now know that there are quantum-mechanical events that are only statistically pre­dictable and the world is not made of Newtonian billiard balls. But that is not much help because Newtonian physics is actually a pretty good description of events at the scale at which we live and nobody seriously believes that we rely, for our free will, on the probabilistic scaffolding of Heisenberg's uncertainty principle. To put the reason bluntly: in deciding to write this chapter this afternoon, my brain did not play dice. To act randomly is not the same thing as to act freely — in fact, quite the reverse.8

Chaos theory provides a better answer to LaPlace. Unlike quantum physics, it does not rest on chance. Chaotic systems, as defined by mathematicians, are determined, not random. But the theory holds that even if you know all the determining factors in a system, you may not be able to predict the course it will take, because of the way different causes can interact with each other. Even simply deter­mined systems can behave chaotically. They do so partly because of reflexivity, whereby one action affects the starting conditions of the next action, so small effects become larger causes. The trajectory of the stock market index, the future of the weather and the 'fractal geometry' of a coastline are all chaotic systems: in each case, the broad outline or course of events is predictable, but the precise details are not. We know it will be colder in winter than summer, but we cannot tell whether it will snow next Christmas Day.
Human behaviour shares these characteristics. Stress can alter the expression of genes, which can affect the response to stress and so on. Human behaviour is therefore unpredictable in the short term, but broadly predictable in the long term. Thus at any instant in the day, I can choose not to consume a meal. I am free not to eat. But over the course of the day it is almost a certainty that I will eat. The timing of my meal may depend on many things — my hunger (partly dictated by my genes), the weather (chaotically determined by myriad external factors), or somebody else's decision to ask me out to lunch (he being a deterministic being over whom I have no control). This interaction of genetic and external influences makes my behaviour unpredictable, but not undetermined. In the gap between those words lies freedom.

We can never escape from determinism, but we can make a distinction between good determinisms and bad ones - free ones and unfree ones. Suppose that I am sitting in the laboratory of Shin Shimojo at the California Institute of Technology and he is at this very moment prodding with an electrode a part of my brain some­where close to the anterior cingulate sulcus. Since the control of 'voluntary' movement is in this general area, he might be responsible for me making a movement that would, to me, have all the appear­ance of volition. Asked why I had moved my arm, I would almost certainly reply with conviction that it was a voluntary decision. Professor Shimojo would know better (I hasten to add that this is still a thought experiment suggested to me by Shimojo, not a real one). It was not the fact that my movement was determined that contradicted my illusion of freedom; it was the fact that it was determined from outside by somebody else.
The philosopher A. J. Ayer put it this way:9

If I suffered from a compulsive neurosis, so that I got up and walked across the room, whether I wanted to or not, or if I did so because somebody else compelled me, then I should not be acting freely. But if I do it now, I shall be acting freely, just because these conditions do not obtain; and the fact that my action may nevertheless have a cause is, from this point of view, irrelevant.
A psychologist of twins, Lyndon Eaves, has made a similar point:10
Freedom is the ability to stand up and transcend the limitations of the environment. That capacity is something that natural selection has placed in us, because it's adaptive ... If you're going to be pushed around, would you rather be pushed around by your environment, which is not you, or by your genes, which in some sense is who you are.

Freedom lies in expressing your own determinism, not somebody else's. It is not the determinism that makes a difference, but the ownership. If freedom is what we prefer, then it is preferable to be determined by forces that originate in ourselves and not in others. Part of our revulsion at cloning originates in the fear that what is uniquely ours could be shared by another. The single-minded obses­sion of the genes to do the determining in their own body is our strongest bulwark against loss of freedom to external causes. Do you begin to see why I facetiously flirted with the idea of a gene for free will? A gene for free will would not be such a paradox because it would locate the source of our behaviour inside us, where others cannot get at it. Of course, there is no single gene, but instead there is something infinitely more uplifting and magnificent: a whole human nature, flexibly preordained in our chromosomes and idio­syncratic to each of us. Everybody has a unique and different, endogenous nature. A self.

我在<关于自由意志和奴役>一文中，提到了休谟对自由意志问题的诘问，刚刚发现它的原始出处，出自其《人性论》（A Treatise of Human Nature, 1739）第二卷，第三章（论意志与直接情感），第一节（论自由与必然）和第二节（论自由与必然（续）），下面是部分段落（摘自商务印书馆1982年版）：

休谟认为，如果我们能对无生命世界进行因果推断，那就没有理由阻止我们对人的行为也这么做：

……根据经验证明，我们的行为与我们的动机、性情、环境，都有一种恒常的结合……

在人类的行动中，正像在太阳和气候的运行中一样，有一个一般的自然规程。有些性格是不同的民族和特殊的个人所特有的，正如有些性格是人类所共有的一样。我们关于这些性格的知识是建立在我们对于由这些性格发出的各种行为的一致性所作的观察上面的；这种一致性就构成了必然性的本质。

然后休谟回答了一种反对意见：人的行为虽然有原因可循，但其捉摸不定和变化无常的特征无可否认：

我所能想到躲避这个论证的惟一方法，就是否认这个论证所依据的人类行为的一致性。只要各种行为和行为者的境况和性情有一种恒常的结合和联系，那么我们不论如何在口头上不承认必然性，而在事实上就承认这回事了。有人或许会找到一个借口，来否认这个有规则的结合和联系。因为，人类的行为不是最为捉摸不定的么？还有什么比人类的欲望更为变化无常的呢？还有什么动物比人类不但更为违背正常理性，而且更为违背自己的性格和性情的呢？一个小时，一个刹那，就足以使他从一个极端变到另一个极端，就足以推翻他费了极大的辛苦和劳动才确定下来的事情。必然性是有规则的、确定的。人类的行为是不规则的、不确定的。因此，人类行为并不是由必然发生的。

休谟回答是：自然同样捉摸不定、反复无常，但我们却并不因此摒弃因果律：

对于这个说法，我答复说，在判断人类的行为时，我们必须依照我们对外界对象进行推理时所凭借的那些原理。当任何一些现象恒常而不变地结合在一起时，它们就在想像中获得了那样一种联系，以至使想像毫不犹疑地由一个现象转移到另一个现象。不过在此以下还有许多较低极的证据和概然性，而且单独一个相反的实验也不足以完全破坏我们的全部推理。心灵把各种相反的实验互相对消，从多数中减去少数，根据剩下的那种程度的信据或证据进行推理。即使当这些相反的实验的数目完全相等时，我们也不消除原因和必然的概念：我们仍然假设，这种通常的反对是由相反的、秘密的原因的作用而发生的，并且断言，所谓机会或中立性只是由于我们知识的缺陷而存在于判断中间，并不存在于事物自身，事物自身在任何情形下都是一律地必然的，虽然在现象上并不是一律地恒常的或确定的。没有任何一种结合比某些行为与某些动机和性格的结合更为恒常而确定的了；如果在其他情形下那种结合是不确定的，那也不超过于物体的活动方面所发生的情况，而且我们根据心灵活动的不规则性所推出的任何结论，没有一条不可以同样地根据物体活动的不规则性推出来的。

接着，最精彩的一段出现了，这是休谟对自由意志论者的致命诘问，大意是：如果自由意志是因果决定的对立面的话，那么疯子就是最自由的了，因为对他们的行为最难作出因果推断：

疯人们一般被认为是没有自由的。但是如果我们根据他们的行为加以判断，这些行为比理智清楚的人的行为有较小的规则性和恒常性，因而是较为远离于必然性的。因此，我们在这一点上的思想方式是绝对矛盾的，但它只是我们在自己的推理中（尤其是在现在这个问题上）通常所运用的这些胡涂的观念和含混的名词的自然结果。

现在我们必须表明，动机和行为之间的结合既然像任何一些自然活动的结合一样、具有同样的恒常性，所以它在决定我们由一项的存在推断另一项的存在方面对于知性的影响也是一样的。如果这一点显得是对的，那么凡是加入各种物质活动的联系和产生中的任何已知的条件，没有不可以在心灵的一切活动中发现出来的；因此，我们如果认为物质方面有必然性，而认为心灵方面没有必然性，那就不能不陷于明显的矛盾。

最后，（在第二节中）休谟指出，自由意志论的糊涂，源自于对“免于暴力强制的自由”和“中立的自由”（即自由意志）的混淆，我才发现，原来休谟不仅提出了问题，也给出了答案！

我相信，我们可以给自由学说的流行提出下面三个理由，虽然这个学说不论在任何一个意义下都是荒谬和不可理解的。第一，当我们已经完成任何一种行动以后，虽然我们承认自己是被某些特殊观点和动机所影响，可是我们难以说服自己是被必然所支配的，是完全不可能作出另外一种行为的；必然观念似乎涵摄我们所知觉不到的某种力量、暴力和强制。很少有人能够区别自发的自由（如经院中所称）和中立的自由。很少有人能够区别与暴力对立的自由和意味着必然与原因的否定的那种自由。第一种意义甚至是这个名词的最常见的含义；我们所注意保存的既然只有那种自由，所以我们的思想主要就转向了它，而几乎普遍地把它与另一种自由混淆了。

第二，甚至关于中立的自由，人们也有一种虚妄的感觉或经验，并把它作为自由真正存在的论证。不论是物质的或心灵的任何活动的必然性，严格地说，并不是主动因的一种性质，而是可以思考那种活动的任何有思想的或有理智的存在者的性质，并且就是人的思想由先前对象来推断那种活动的存在的一种确定的倾向：正像在另一方面，自由或机会只是那种确定倾向的不存在，只是我们感觉到的一种漠然，可以随意由一个对象的观念转到或不转到另一个对象的观念。现在我们可以说，在反省人类行为时，我们虽然很少感到那样一种漠然或中立，可是通常有这种事情发生就是在完成那些行为本身时，我们感觉到与此类似的某种状况：一切相关的或类似的对象既然都容易被互相混同，所以人们就以这一点作为关于人类自由的一种理证的证明，甚至作为一种直观的证明。我们感觉到，在多数场合下，我们的行动受我们意志的支配，并想像自己感觉到意志自身不受任何事物支配；因为当人们否认这点、因而我们被挑激起来亲自试验时，我们就感觉到意志容易地在每一方面活动，甚至在它原来不曾定下来的那一面产生了自己的意象。我们自己相信，这个意象或微弱的运动，原来可以成为事实自身；因为如果否认这一点，则我们在第二次试验时会发现它能够如此。但是所有这些努力都是无效的；不论我们所能完成的行为是怎样任意和不规则，由于证明我们自由的欲望是我们行动的惟一动机，所以我们就永远不能摆脱必然的束缚。我们可以想像自己感觉到自己心内有一种自由；但是一个旁观者通常能够从我们的动机和性格推断我们的行动；即使在他推断不出来的时候，他也一般地断言说，假如他完全熟悉了我们的处境和性情的每个情节，以及我们的天性和心情的最秘密的动力，他就可以作出这样的推断。而依照前面的学说来说，这正是必然的本质。

科学的信息学阐释（一）
辉格
2008年12月27日

对于“什么是科学？”这个问题，在我刚接触科学哲学的时候，我的想法比较朴素：科学是用来解释事实的。那什么叫解释呢？我说：解释就是降低听众对某些事件的惊讶程度，即，解释者所面对的那些听众，在听过他的解释之后，对原本让他们较为惊讶的事件感觉不再那么惊讶了，这种差异越强烈，我们就说：解释者所持理论的解释力越强。（当然，前提是他的理论是逻辑自洽的，这一点先不讨论）

有一段时间，我对自己的这一表述比较满意，但总是觉得它不够形式化，如果解释者面对的不是人而是机器，这一区别方法还能有效吗？于是我想，如果要让一台机器对不同的事件表现出惊讶或者泰然，我会如何着手？

假如你掷4个一组的骰子，A)掷出4个6会让你很惊讶，B)掷出3个6、1个2个则略感惊讶，C)掷出2、3、5、6各1个则丝毫不惊讶，差别在哪里？我是这样想的：人对之惊讶的东西，不是事件，而是现象，上面三次掷骰子，就事件本身而言，其在整个事件空间中所占据的位置，是同等的，但它们所表现出的现象——或者说当我们用某种语言把它们表述出来时，则十分不同：这三个现象所覆盖的事件，所占据事件空间的比例分别是：A=1/1296，B=4/1296，C=12/1296。

一个现象所占据的事件空间的比例大小，对应着观察者从该现象中所获得的信息量的大小，比例越大，信息量越小。可以这样理解：有人问你住在哪里，你回答1)广东2)广州3)海珠区，这些答案占据事件空间的比例一个比一个小，所含信息量一个比一个大。反过来，事件空间的缩小，也会降低该空间中事件的信息量。比如，在一个9x9棋盘上的一颗落子，比在19x19的棋盘上，信息量小很多。

所以，区分惊讶与否的关键是信息量。于是，我把“解释”一词的含义形式化为：所谓解释，就是对原有的事件空间（S）追加约束（R），使得被解释现象（P）的信息量从原有的I0减少为I1，且约束本身的信息量Ir小于I0-I1。科学，通过引入一组自然律，约束了事件空间，因而降低了现象在观察者眼里的信息量，从而达到了降低惊讶程度——或者说解释的效果。

还是拿骰子说明：假如你连掷三次，结果都是1、2、3、4各一个，你感觉很惊讶。此时，一位骰子科学家提出“点数守恒定律”——一次掷四颗骰子的点数之和恒等于10，并以此作为对上述现象的解释。看看是否与我的说法吻合：在没有守恒定律之前，事件空间（S0）的容量是6的4次方1296，“1234各一个”这一现象占据了该空间的12个位置，其信息量I0=-log2(12/1296)=6.75bit【注】，引入点数守恒定律之后，新的事件空间（S1）的容量为83，于是“1234各一个”的信息量变为I1=-log2(12/83)=2.79bit，比I0减少了3.96bit。

那么点数守恒定律本身包含了多少信息量？四颗骰子点数和的值空间是6～36，容量31，因而定律的信息量Ir=-log2(1/31)=4.95bit，超过了其节省的3.96bit，但这一定律不仅能解释(1,2,3,4)骰子组合，至少还能解释如下6种组合：(1,1,2,6)，(1,1,3,5)，(1,1,4,4)，(1,2,2,5)，(1,3,3,3)，(2,2,3,3)，所以，它节省的总信息量是3.96bit*7=27.72bit，这样，该定律一共节省了22.77bit。

好久没做代数题了，请大家帮我检查一下有没有算对。

（未完待续）

注：信息量的计算方法，见Wiki条目：熵（Entropy）。

若以奥数成绩衡量，中国学生所受的科学教育不可谓差，而美国学生可能要倒数了，但我的判断却仍然是：中国的科学教育极其失败，而美国的科学教育仍属一流。

差别在于哲学。科学是一套独特的思考、说话和交流方式，奥数考100分，并不意味着你已经学会用科学的方法来思考和说话了。

在英美科学家的著作里，你常常可以看到大段大段文字阐述他们的哲学和方法论基础，波普、卡尔纳普、库恩的名字和术语随处可见，而在中国学者的作品里，你最多只能听到一些前罗素哲学家的警句妙言。

对于没有起码了解科学方法论的人来说，阅读科学新闻和看明星八卦没有区别，除了满足一点好奇心和获得一点遐想空间之外，我看不出对改进他们的思考有任何益处；我经常在朋友之间宣扬的一个观点是：对大众来说，科学就是另一种迷信，也只能是一种迷信。

所以，至少在中国，最需要普及的，是科学哲学。

如果你有足够的时间，我会贪婪凶恶的推荐从休谟、罗素、维特根斯坦、波普、库恩、拉卡托斯直到奎因，但很少人有这样的时间和耐心，所以，我建议，如果只打算读一本科学哲学著作，就读这本吧。

我在<土地确权蹒跚前行>一文中提到了标准化对于产权市场化和金融化的必要性，一方水对此表示不解，解释一下： 我用“标准化”这个词是为了显得通俗一点，其实我更喜欢用“离散化”或“数字化”，偶尔我也用“符号化”这个词。所谓离散化，相对于连续化，我的意思是：将一种事物的可能状态限制为事先可知的有限小集合（小到通常不超过几十个元素），并且，每两种状态之间，有足够大的间隙来加以区别。 具体到财产和交易领域，有很多离散化的例子：标准期货合约，FOB/CIF/C&F等贸易条款，有限责任公司/股份公司/私人合伙/有限合伙等若干企业组织形式，普通股/优先股/AB股等若干股权形式…… 正是因为有了这些离散化，大大简化了交易，也为在此基础上发展出更复杂的契约和组织形态创造了条件，交易者不必为每一笔交易仔细议定条款，投资者也不必仔细阅读每家上市公司的组织章程，试想，如果基础产权没有标准化，大规模交易如何展开？以此为基础的衍生品如何设计？几乎没有可能。 对离散化重要性的分析可以扩展到几乎所有领域，可以这么说，没有离散化，任何可持续的复杂结构都不可能产生。这个话题非常有意思，甚至令人激动，我早先曾想专门写篇文章，但一直没时间完成，下面是未完成稿中的一段：

数字化不是现代信息科技的产物，它的历史至少比原子古老，我不知道夸克是什么样的，但我知道原子结构是离散的，因此所有同位碳原子都是一模一样的，不像汤圆那样有大有小，也因此，原子才能精确的搭建和复制出复杂结构，不至于成为一滩烂泥。

音乐是很好的例子。除了古琴和二胡等少数几种弦乐器，我们今天能见到的所有乐器都已经符号化了——只能演奏出有限的一组音阶。没有音阶，或许能得到一段美妙的旋律，但要创作出复杂的乐曲并且流传出去，几乎没有可能。

没有音阶，除非当面演奏，你无法表达一首乐曲，也难以记忆，学习也很困难，最糟糕的是，流传几次以后就变得面目全非——我听过两位大师演奏的《广陵散》，长度差三倍，说实话我听不出任何相似之处。

复杂的乐曲是一段段旋律、一个个主题组合起来的，如果你无法精确表达、记忆、复现、传授一段旋律，你也就无法创作出复杂的乐曲，尤其是在古代，那时的艺术作品往往是在流传过程中逐步丰富的。

语言是另一个例子。语言本身就是符号化的结果，没有离散化的有限音节集合，就没有语言

现在我们已经知道，基因和蛋白质也是数字化的，4种碱基，最多64种氨基酸（算上标点符号），没有数字化，生命不可能出现。

（按：这是我07年初系列文章中的最后一篇，正是这一系列文章，让我自绝于我的自由主义朋友们，也自绝于广大人民，从此沦为最顽固的反动派，呵呵。通过这个寓言，或许可以加深对波普三个世界、哈耶克自发秩序和社会进化的理解，果如此，我就满意了，至于其它，由他去吧） 沙器和蚁穴：举例详解自发秩序 作者：辉格 2007年4月28日 设想你正在一个沙滩上，尝试着用沙子堆砌出一座你想象中的楼台。这时，你的大脑里一定已经有了一个楼台的“模型”，而你的堆砌工作便是将这一观念模型“投影”到沙子上，从而改变了世界。这样说来，观念改变世界，甚至观念“决定”世界，看来是如此显明而无可置疑。 假设情况略有变化，现在不是一个人，而是你和你的伙伴两个人，一起蹲在沙滩上，合力建造一座楼台。情况便略显复杂。堆砌的结果，是与你的观念模型更相似，还是与你伙伴的更像？或许你们的模型恰好就大同小异？或许你的伙伴情愿听从你的指挥而让建造过程沿着你的设想进行？或许你们经过讨论事先获得了一个“共同的”模型？或许你们发现言语已不能准确描绘这个共同模型所以用纸和笔把它画了出来？ 是的，一旦需要两个以上的人合力将一个观念投射到现实世界，就不可避免的需要表达、设计、控制和服从。正是设计与控制，让人类完成了许多单个人无法完成的工作，将一些宏伟的设想变成了现实。 然而人类行为还会以另一种完全不同的方式改变世界。设想一大群蚂蚁，正在一个土丘旁建造蚁穴，那些奔来跑去忙忙碌碌的蚂蚁，很难设想它们的头脑里预先有一个蚁穴的“模型”，即使蚁穴已经建成，它们中也没有一只能看到它的全貌，更难以设想会有一只蚁王，设计并指挥了整个蚁穴建造工程。 但是蚁穴的确建成了，有序而宏大，精致且齐全，通风口、过道、仓库、育婴室，一应俱全。 人类也曾进行这样的建造，语言、戏剧、集市、贸易体系，乃至巨大的社会。这些复杂系统出现之前和生成期间，它们的模样未曾出现在任何一个参与建造者的脑海之中，甚至在它们已然成型，无处不在之时，许多人仍对之懵然不觉。 将人类创造文明社会的过程类比于蚂蚁建造蚁穴的过程，这或许给人们暗示了一幅关于世界的灰暗图景，但尽管灰暗，这图景看来更接近现实。 哈耶克用了一个贴切的词汇——自发秩序——来描述这种建造和发展过程，然而对于这个词汇，仍有几点需要澄清： 第一，自发秩序排除了事先的人为设计，就是说，系统建造之前和发展之中，没有任何与之相对应的观念模型预先存在于任何参与建造者的头脑中。 第二，否认有预先存在的观念模型，并不意味着观念不能对系统建造过程产生影响，甚至决定性的影响。 自发秩序意味着，而且仅仅意味着，某些复杂系统的产生与否，并不依赖于与之相对应的观念模型是否预先存在于参与其事的人们的头脑中。或者说，蚂蚁脑中是否有蚁穴的样子，与蚁穴是否会被建造出来，毫无因果关系。 文章贴出后的一些评论： 辉格（自言自语）：

那么，自由主义观念的传播，与自由社会的建造，是否有逻辑关系？ 不要因为一个答案色调灰暗就拒绝这个答案，上帝不曾保证任何问题的正确答案都是光明的，呵呵。

abada:

英国没有成文宪法. 但有不成文的宪法观念和理念. 否则英国就无法判定什么是违宪的法规了. 具体的法律不能被设计, 不是说宪法和立法的基本准则和规则不能被设计. 否则等于否定了法治. 一切回到原始社会从头开始文明. 不可知论不能告诉人们应当如何行动, 但人们行动是有目的的, 需要目的.

辉格（答）：

“否定了法治. 一切回到原始社会从头开始文明.”？ 你我头脑里一“否定”，一切便“从头开始”了？有这么奇妙？传说中的魔法师？你认为毛时代的制度形态，与马克思头脑里的某个观念模型，具有相似性？我从不否定观念可以改变世界，而且这里又强调了一次，请看原贴。我否定的是：参与者的观念模型与集体行动所造成的客观形态之间必须的相似性。我认为没有这种相似性。落实到自由制度这个具体问题，我认为自由制度从来不是将来也不会因为某些人领会并接受了自由主义思想而得以建立。

AK47：

我认为有。不过不一定要传播到每个人，在社会精英中形成共识即可 如果社会的精英阶层很少认同自由主义的理念和规则，要建成自由社会是不可想象的。当然，这种认同可能以多种方式形成，如： 1，经过多年试错，各种“主义”都试过了。最后运气好（当然，也离不开一些人倡导），试到了自由主义。大家一看效果不错，于是就认可了。（如英国、法国） 2，自由主义精英另起炉灶，由于包袱少，搞出一个更好的自由社会。（如美国、加拿大、澳洲） 3，信奉自由主义的人在外国掌握了绝对统治权，统治时间一长，原来不知自由主义为何物的本地精英看到效果不错，也认可了。（如德国、日本；弱一点的像韩国、香港；至于伊拉克、阿富汗，难度更大。） 4，本地的一些精英，知道自由主义的好处，就不停呼吁、传播、抗争，最后成功了。（典型如台湾） 总之，就自由主义理念而言，社会精英阶层的认可至关重要。对一般民众而言，未必要认可“自由主义”，但起码要有指向“自由主义”的习俗、宗教、文化基础。 否则，就像你举的例子，社会精英像蚂蚁，普通大众也像蚂蚁，这群蚂蚁如何能建立一个自由社会？是出于他们的本能吗？如果是的话，难道专制社会中的蚂蚁的本能，与自由社会中的蚂蚁的本能有什么不同吗？显然不是。 回过头看我列举的1、2、3、4点，其实，自由社会的建立过程，就是自由主义理念的扩散过程。

辉格（答）：

我眼中的历史和你的大不相同 1.1）英国宪政可不是试来试去试出来的，几百年后辉格史学编造了自由主义的“长期奋斗史”，那些剑指国王的男爵们，脑子里果真装着自由主义？ 1.2）欧洲大陆的（特别是法国的）知识分子倒真是试来试去试了一百多年，结果是什么？不是社会主义吗？AK不至于认为法国社会算是理想中的那种自由社会吧？ 2）说殖民时代的美国是一张白纸、另起炉灶，离现实更是十万八千里，清教徒殖民者的包袱不仅不少，简直就是把英国老古董不分青红皂白一股脑搬了过去。 3）自由制度移植成功的两个罕见典范，德国和日本，之前都标准封建社会，拥有英国宪政所产生的那种土壤。 4）“不停呼吁、传播、抗争，最后成功了”——我不否认这种努力的功效，我是想提醒大家仔细看看当时“呼吁”和“传播”的到底是什么？“抗争”的动机和力量到底是什么？它们和“最后成功了”的那个制度之间的有多大的相似性？ 人类蚂蚁有观念，观念可以改变世界——我再次重申我不否认这一点——，这就意味着专制社会中的蚂蚁和自由社会的蚂蚁，确可以有不同的观念，并因此导致了不同的社会形态，这没问题，也恰是我十分有兴趣的事情。 我否认的是：这两群蚂蚁的不同观念，与两种社会形态之间，是否有相似性？用数学语言说就是，观念与社会形态 之间，是否存在映射关系？

学经济家（插话）：

辉格是认为，进化没那么简单直线。 我认可辉格的思路，举个例子。我很早对农村土地私有乐观，由原来的半世纪缩短到十几年，是因为发现许多人在农村有大量租地。那时国内还根本没看到精英们传播土地私有观念的证据。 社会演化可能与生物演化很相似。土地私有的病毒在原有肌体内不声不响的复制着，直到一定时段才打喷嚏。在打喷嚏这个临界点以前，不必因为肌体毫无表现，就表示悲观。或者反过来，认为肌体要放倒，得有人撩动它的鼻毛，让它打喷嚏，才是正路。 精英的理念，或者其传播的声音，往往是改变的结果，而不是改变的起因。 因果确实比较难断定。

（按：这是我唯一一次参与类似座谈会并发言，有趣的是，我一开始发言就感觉到在此类场合发这种言毫无意义，也很可笑，所以我大概不会再参加类似活动了。除了这篇发言稿，我后来还又写了<沙器和蚁穴：举例详解自发秩序>一文来更清晰的说明我的思想。下文删除了两个无关段落，附上两段会后讨论） 理想与路径：某次座谈会发言稿 作者：辉格 2007年4月14日 我想，对于一个理想社会应该是什么样子，今天在座的各位，大概有着许多共同的看法，但是，对于一个社会如何可能从现在这种或以前那种很不理想的状态，变化到比较理想的状态，我猜想，每个人的看法可能大不相同。 正因为有这种差异，我们对于现实中发生的每件事情的评价，对于做什么才有助于那些理想或多或少变成现实，常常吵得不可开交，在我看来，这种情况太正常了，对于社会这种复杂系统的发育和演化问题，如果会有一个简单明了的解摆在你跟前，可以方便的用做度量各种事件的尺子，或指导行动的纲领，那才是一件非常奇怪的事情。 所以，我不认为自己已经拥有某种理论，能让我断然的判断某件事情，或某种行动，是让我们更加接近还是更加远离我的理想社会，但是，我自认为已经察觉到人们在做这样的判断时经常会犯的一些错误，这些错误多半是因为忽视了社会是一个复杂系统，因而惯于使用各种线性思维，比如： 出现一件在理想社会中更常见，而在当前社会中不常见的事情，是否多半会有助于理想社会的实现？（例：某人希望他儿子将来成为影星，而影星经常闹绯闻，所以应该让儿子从小闹点绯闻。） 那些在理想社会中将被认为非法的事件，是否多半会阻碍理想社会的实现？（例：某人希望他儿子将来成为少林寺方丈，所以从小不给他吃肉，因为对和尚来说，吃肉是非法的。） 各位大概会同意，一种社会状态能够被一些人认同为是理想的，前提是这些人或多或少具有一些共同的价值观和伦理观，那么，是否每一件被这个共同价值观判定为善，或者被共同伦理观判定为好的事情，多半会有助于理想社会的实现？（例：未经代议机构同意私自瓜分国有资产，皮诺切特的镇压行动，都是违背自由主义伦理的，所以肯定会使社会更加远离自由制度。） 还有，构成理想社会复杂结构的每一个部件，当它单独出现时，是否都意味着我们距离理想社会更近了？（例：某人希望他儿子将来成为钢琴家，每个钢琴家的客厅里都少不了一架三角钢琴，所以，当他把三角钢琴搬进客厅的那一刻，便到达了儿子成长为钢琴家的道路上一个重要里程碑。） 之所以提出这些问题，是因为据我的观察，很多人在进行分析时，显然对上面这些问题假定了毋庸置疑的答案，就好像问题根本不会存在。但是你只要仔细想想，这些问题在逻辑上并没有显而易见的答案，所以，对于那些显然没有意识到这些问题存在的分析，我总是抱着十分怀疑的态度，在我看来，这些问题的答案远远不是一目了然的，甚至常常是与我们的直觉相悖的。 比如，人类从政教合一的社会发展出政教分离、信仰自由的社会的历史，看上去并不是某种宗教宽容主义或文化多元主义长期努力的结果，相反，它更像是各种形形色色的宗教极端主义相互争斗、僵持不下最后只好达成妥协的结果。 在这段历史中，最后得到的结果被宽容主义和多元主义认为是可欲的，但推动这一变化过程的那些关键力量，却没有一个是主张宽容和多元化的，这种看法听上去有点荒谬，却更接近事实，至少我这样认为。 再比如美国，保守派在宗教、科学和生活方式上的那些原教旨主张显然在理论上和价值观上都难以被自由主义者所接受，但事实是，正是这些讨厌的狂热分子，成了在美国捍卫自由的中坚力量。 我说这些，并不是要让自由主义者都放弃他们的理论和价值观，去做狂热的异端分子，我只是希望大家放平心态，不要指望用自己的理论指导行动，就可以推进理想社会的实现，现实远远不是那么回事。我要再次强调的是，评价事件和行动对于社会演化的影响，这是一个发生学问题，不是一个静态度量问题，也不是一个规范分析问题，更不是一个价值判断问题。 附记一： 注：事后有人反映没听懂，我就在四个问题后面补了例子 我发言时自己也感觉有点绕口令的味道，虽然句法并不算复杂，呵呵。 附记二： 后来喝茶时谈起读经和宗教问题，我说： 1）乐见其成。——虽然我不是基督徒，却挺乐意生活在一个基督徒较多的社区里。 2）理解秋风他们的这种努力。——宗教的来世、天国、末日审判、天罚等，改变了信徒在博弈决策时的成本收益算法，提高了重复博弈的预期重复率，使合作博弈更容易涌现，因而有助于市场和法治规则的建立。 对此老盾提出两点质疑： 1）宗教偏执很可能伤害自由； 2）宗教对规则建立不是必需的。 我的回答： 1）这种伤害多半出现在宗教与权力结合时，也就是一种宗教取得垄断地位时，这与一种意识形态取得垄断地位是相似的，不是宗教特有的危害； 2）我也不认为是必需的，只是认为会有较大的帮助，提高了博弈预期重复率的可能因素有很多，文化符号、家族观念、关于英雄和坏蛋的民间传说和文字作品，等等，任何能将个人价值判断的时间域扩展到他的寿命以外的东西，都有类似的作用。 附记三： AK47的疑问：你说半天的意思是不是我们对于评价事件和社会演进之关系完全无能为力？ 回答：不是这样，我只是指出了四种常见的简单化评价方法缺乏逻辑基础，但并不否认可能找出一些有效的评价方法或理论，虽然我自己没有，但别人可能会找出一些。 补充：我感觉基于博弈论的演化分析可能有点戏，虽然也很渺茫。