（按：这本来应该是两篇文章，但我估计短期内不会再有有偿发表的机会，所以就拼在一起了，不过我在中间做了明确的过渡，大概不至于混淆，另外，因为是饭文，有些地方没说太细，回头我会做些补充） 拒绝动物拥有权利是无可退让的底线 辉格 2012年2月24日 归真堂事件仍在继续发酵，从舆论势头看，即便此事被淡忘，还会有下一件、下下件，这是个正在兴起的潮流，今后若干年的公共议题中我们会看到它的反复出现，所以不妨在此刻多费些口舌，把日后注定会遭遇的交火点提前拿到台面上来。 假如这仅仅是一股价值观潮流，其所宣扬的仍是人类的利益诉求、人类的价值关切——保护物种多样性，是为了人类生活在一个更好的生态系统中，保护某些动物免遭虐待，是出于人类恻隐之心，是为了避免人类因此而遭受的痛苦——那就没什么好紧张的，即便其主张目前看来难以成立，未来或许会成立，毕竟，新的价值观总是在不断涌现，新型权利也时常被确立，一个开放社会理应能够接纳和适应这种变化。 然而动物保护主义（[[animal protectionism]]）的主张却不止于此，许多甚至构成其主力的保护主义者，是要赋予动物以权利，即，承认动物可以成为权利的主体，这就断难接受了，假如这世上有什么事情可以称作“大是大非”的话，这就是，因为它直接从根基上挑战了我们据以评判是非的伦理标准。 实际上，动物权利论（[[animal rights movement|theory of animal rights]]）并不是对这一伦理基础的首次挑战，它是一个多世纪以来在制度和政策领域日益蔓延的福利主义传统的自然延续；在福利主义看来，个体价值追求的结果是可以用某些客观指标（诸如收入、健康指数、快乐指数、幸福指数之类）来度量的，并且度量结果可以加总为社会总福利，因而这个总福利的高低和增减便可以用来评价一项制度或政策的好坏。 一旦承认了个体价值的客观可度量性，其自然的后果便是对权利概念的歪曲和滥用；在我们古老的伦理观念中，权利从来都是与自由意志联系在一起的：当我们判定一项财产转手是自愿交易还是抢劫或偷窃，一次两性交往是约会还是强奸，一次赤手肉搏是拳击比赛还是人身侵犯，辨明当事人的自由意志是否被违背，无疑都是判断的关键。 原本，确立和保护权利是为让权利主体能够按其意愿追求和保有他所珍视的价值，通俗的说，就是“为了他好”，现在既然价值是可客观度量的，福利主义者便可以说：什么才是“对他好”无须询问他自己，也无须由他自己决定，我们只须按照度量结果为他安排那些能让他变得更好的条件即可。 潘朵拉之盒由此打开：为了你的孩子好，我可以强制你把他送进我指定的学校，强制你把指定数量的收入拿来支付孩子学费，为了你好，我可以禁止你不能吃哪些食物，禁止你在哪些劳动条件下工作，强制你拿出指定数量的收入购买医疗和养老保险，也是为了你好，我可以禁止你卖掉你的房子和土地，免得你拿去换酒喝或在赌桌上输个精光。 不仅如此，福利主义者为这些强制行径都取了个好听的名字，叫做“权利”：教育权、健康权、养老权、居住权、公平起跑线权，等等；但在这串令人眼花缭乱的“权利”清单中，权利的核心要素——自由意志——却已消失的无影无踪。 于是，我们便看到了它的下一个逻辑后果：既然自由意志不再是权利的核心要素，既然福利高低无须由权利主体自己说了算，那为何不会说话也不能表达意志的动物就不能拥有权利呢？确实，这一推导十分自然，实际上，最早提出动物权利观的，恰恰就是功利主义（[[utilitarianism]]）哲学的祖师爷杰里米·边沁（[[Jeremy Bentham]]），而功利主义正是福利主义的哲学基础。 所以，动物权利论其实是福利主义的一种极端形态，它在常识直觉上就显得极其荒谬，在持个人主义（[[individualism]]）和主观价值论立场的人看来，它是在一个极端边界上归谬了福利主义，然而在现实舆论中，荒谬性本身似乎并未能阻止其传播并获得影响力（这一局面也并非没有先例，二十世纪的许多主义都在展示出其荒谬性后继续扩张乃至走向狂热）。 在这场伦理观念的对抗中，个人主义者早已失地无数，如今他们被逼到了底线，再退让下去，个体和自由意志这个东西将从伦理话语中被彻底清除掉。 个人主义者之所以执意捍卫他们的伦理立场，首先当然是因为他们不想让别人来摆布自己的命运，不想让别人代替他们做价值判断和行动选择，这些事情在他们的道德直觉上便是不可接受的；其次，当他们试图说服别人接受基于他们的伦理观来维护和建设现实生活中的法律体系时，自然也会在元伦理的层面上提出一些现实理由，这些理由难免带有某种功利性，这在任何辩护和说服他人的任务中都是难免的，也并不意味着他们主张的伦理体系本身是功利主义的。 关键的不同是，个人主义用来说服他人的功利性理由，所需要的价值共识是最小的，比如哈耶克所提出的，维持多元价值人群的和平共存，确保现有人口规模和繁荣程度的文明得以延续，等等，很难被公然否定；因此，在我表达了自己的价值立场之后，再为个人主义从现实功利性上提出一些辩护，或许不是多余的。 我们知道，法律是一些约束个体行为的规则，其意义在于建立某种秩序从而避免丛林状态，就通过规则约束行为这一点而言，它与象棋、桥牌、足球等游戏中的规则很像，人们也经常做这样的类比。 但这里有个关键差别：游戏规则通常由一组禁则（[[regulation]]）组成，所谓禁则就是无条件禁止某种行为，与犯规者的对手是否同意无关，即，这里没有自由意志；而法律规则却不同：除了禁则之外，还有权利（[[rights]]），后者将是否许可某种行为的判断交给了权利主体；如此安排的规则体系有何好处？答案是：它特别适合于两种情况：1）上帝缺位的游戏，2）非零和博弈（[[non-zero-sum game]]）。 所谓上帝就是那个能预知游戏中所有可能出现情况的规则制定者，假如某些情况无法事先预知，最好交给了解情况的当事某方在情况出现后自己去判断；在竞赛游戏中，由于类似的对局已重复无数次，各种可能情况都已经出现过，所以规则制定者实际上处于上帝的地位，例外是：新游戏流行的最初阶段，当未料到的情况出现时，便需要修改规则。 然而在现实生活中，现在多数人大概都已相信，没有人能够站在上帝视角上来为生活制定规则——除了那些仍将圣经或可兰经奉为上帝律法的少数原教旨主义者之外——，因为生活实在太复杂了，可能性和变化也太多了。 即便在竞赛游戏中，也有规则制定者永远无法预知的情况，比如桥牌中的越序出牌（lead out of turn），人们发现，禁止一个已经作出的越序出牌生效，有时反而不利于违规者的对手，而有利与否，取决于事先无法预知的特定局面，所以桥牌规则规定，是否接受一个越序出牌，由违规者的对手凭其自由意志自行决定。 游戏与生活的另一个区别是，几乎所有竞赛游戏都是非胜即负你死我活的零和博弈，而生活中却充满了通过协调与合作实现共赢的非零和博弈，而引入了自由意志和权利规则的系统，更适合于非零和博弈，因为合作的达成常常需要这种意志表达和同意机制。 实际上，在竞赛游戏中，偶尔也会出现非零和博弈的局面，而凡是出现这种局面的地方，通常就会存在权利规则（而非无条件禁则），比如，象棋中的求和，尽早承认并结束一个已经注定的和棋局面，可以节约双方时间与精力，所以，规则便将是否接受一个和棋请求的判断，交给了博弈者，听任其自由意志作出决定。 只要你相信没有人能够站在上帝的位置上为全人类的生活制定规则，而这些规则都是由非权利性的无条件禁则所组成，并且相信生活是高度复杂多变的，充满了难以预料的情况，也充满了协调与合作的机会，那么，你便可以体会到个人主义的魅力，即便你原本并不具有强烈的个人主义道德倾向。

（bibleman问起我对自由意志的看法，恰好我在《自私的皮球》中有一篇清理了自己在此问题上的想法，与我此前的表述有所差别，贴在这里吧） 决定论的意思是：世界任一时刻的状态由其先前状态经由因果关系完全决定。我无意作此断言，在此意义上，我可能算不上决定论者，但我肯定是方法论决定论（methodological determinism）者，即，我认为，只有当我们假定这个世界是决定论世界时，才能有意义的观察、理解和谈论它。 许多人不接受决定论，一个原因是他们将它与宿命论（[[fatalism]]）混淆了，其实这两者是完全对立的，另一个原因是他们觉得接受决定论就意味着否认自由意志，从而丧失道德责任的前提，而实际上自由意志不必依赖于非决定论，我在下面两个帖子里分别作出了分析，对第二种情况的澄清尤其重要，因为它关系到伦理学和法学的哲学基础，我们将在无数话题上反复遭遇它。 〖决定论 vs 宿命论，2009-12-24，No.786〗 （略） 〖关于自由意志和奴役，2008-12-09，No.537〗 （略） 〖后记〗 写过这两段文字后的两年里，我的看法又有所变化，变得更兼容主义[2]了；对于因果决定与自由意志，我现在的看法是：人的行为由之前的世界状态完全决定，但这并不是说他没有做“选择”，而是说他如何选择是被决定了的，因而，世界的因果链并未因为个人选择而被打断，相反，个人选择只是因果链的一部分。 道德哲学家所做的仅仅是：从世界因果链中人为的画出一段，并规定，这就叫“自由选择”，而产生这一选择的那个装置，就叫“自由意志”；由于这是个武断规定，因而无须追问为何如此规定，正如我们无须追问数学家为何用π来命名圆周率一样。 假如哲学家愿意，也可以规定发生在黑猩猩大脑里的一段因果链就是“自由选择”，因而黑猩猩也拥有自由意志，甚至可以规定一个篮球筐也具有自由意志；我在一个旧帖里曾举过一个例子：

向一个篮球筐扔红色和蓝色两种球，每次每种颜色各一个。下面两种说法完全等价：A）十次里有七次红球弹回来，蓝球留下，另三次相反。B）十次里有七次篮球筐“选择”了蓝球，另三次他“选择”了红球。

显然，作为事实陈述，A和B完全等价，区别仅在于说话者看待它们的态度，也就是说，承认或否认自由意志，并不关乎事实的任何差异，这就好比，我们究竟把单只蜜蜂看作一个生物个体，还是把整个蜂巢看作一个生物个体，可以任意定义，无论如何定义对蜜蜂都不会有任何影响。 假如我们规定了篮球筐拥有自由意志，它就对自己的行为负有道德责任，就是合格的法律主体，这么做没有任何逻辑困难；实际上人们并未如此规定，那只是因为他们不愿意。 正因为自由意志的规定不以否定因果关系为前提，任何对因果关系的发现都不构成对它的挑战，为个人行为所找出的任何客观原因，都不构成推卸道德与责任的理由，也只有如此，我们的伦理和法律体系才能建立在一个坚实的基础上，不会因心理学研究不断发现行为的因果关系而被冲垮，才不致于出现像甜饼抗辩[3]那样荒谬的事情。 基于对自由意志的界定，我们可以区分两大理论体系，一个是科学，它没有自由意志概念，即，它同等对待发生在人脑中的因果链和其它任何因果链，不对前者做任何特殊处理，另一个是伦理学，它引入了自由选择和自由意志概念，将发生在人脑中因果链叫做自由选择，把成年人大脑中此类因果链发生于其中的那个装置叫为自由意志，并规定：拥有自由意志的个体对其行为输出负有道德责任[4]，这意味着，指称这些个体的名词或代词可以合法的成为“应该”这一谓词的主语。 我原本认为，科学和伦理学的命题不能一致的共存于同一个形式系统，现在我认为这一限制是不必要的，两类命题是兼容的，唯一的要求是：因为伦理命题的特殊性，所以当它出现时，必须带有明确的标记来显示它是个伦理命题。 ---------------------- [1]在这一点上，我的看法有所改变，见后记。 [2]兼容主义（[[compatibilism]]）认为自由意志概念可以在决定论体系中得到保留。 [3]甜饼抗辩（[[twinkie defence]]）一词源自1979年一宗谋杀案，被告以爱吃甜食导致精神抑郁为辩护理由，结果陪审团被说服，认定被告作案前缺乏预谋能力，因此定了故意杀人罪（[[voluntary manslaughter ]]）而非谋杀罪（[[murder]]），这一结果在旧金山引发了一场街头暴乱，2005年，最高法院大法官斯卡里亚在一宗案件的口头评论中提到并批评了这一抗辩。 [4]实际上还需要加个前提：除非他在输出该行为时受到另一个也拥有自由意志的个体的强制；不过这里不打算展开讨论道德哲学的细节。

对我关于决定论与宿命论的看法，zhangiii大师说：

决定论是想对于非决定论而言。 宿命论我以为是相对于自由意志而言的。 这涉及到决定论是否与自由意志相容的问题。我的答案是相容的，即使宇宙的状态全部由初始状态决定，仍然可以允许自由意志存在。这取决于观察者，即使从外部观察是决定的，而从参与者的主观视角来看，自由意志仍然可以存在。 从逻辑上清晰的描述这种转换也是可能的。因为如果将其转换为语言逻辑的问题，关于自由意志的一系列相容的描述，是依然可以在逻辑上成立并可以通过语言表达出来的，因为自由意志的并没有所谓的本质存在，而是通过一系列命题所显现出来的一个假设。 在上述的引用“既然一切事情都是被决定了的，那么无论你做什么都改变不了什么，是不是你就啥都别做了？” 前面采用了外部视角，而后面又采用了参与者视角，无法形成正确的逻辑推理链条，后面那部分的推论，做什么都没用，实际上变成了不可言说的部分。

我接受zhangiii的说法，但我们的针对性有所不同，为说明这种差异，不妨区分下面几个问题： 1）是否存在一个包含了自由意志概念的、逻辑上自洽的、有意义的系统？我们的回答一样：“是”。 2）这样的系统是否可能是决定论的？即，自由意志是否相容于一个决定论系统？zhangiii认为是，依我的理解，他的观点是：通过语言上的等效转换，可以从一个决定论的系统中，剔除或者引入自由意志概念，而我认为，能否做到等效，取决于自由意志的含义。 3）一种转换的方法是：从因果链中划出一个圈，称之为“自我”，并将此圈内所发生的事件称为“我的决定”，如果仅此而已，那么等效转换是可以实现的，我猜zhangiii意思正是如此。 4）但在我看来，使用自由意志一词的人，通常试图传达更多的含义，他们说“那就是我的决定”时，默含了“我本可以不这么做”的意思，而正是这层默含的意思，与决定论直接冲突。 5）“我本可以不这么做”，不仅与决定论冲突，也与实证方法直接冲突，因为它在理论上就是无法实证的，实际上可以这么说，该冲突表明了，整个实证方法都是建立在决定论基础上的，因而，任何以实证方法为基础的体系（比如科学）都必须排除第（4）点所界定的自由意志。 关于后两点，我在另一篇文章中曾有所论及，可参考。

这次在杭州，翟振明教授、苏振华教授和另一位学者（我忘了是谁）都重点讲解了自由意志、主观价值论（我更喜欢“价值主体间无关性”这一术语）和方法论个人主义这一组密切相关的基本命题，按我的理解，它们是这样的： 1）自由意志论：除非被他人所强制，人的每一项行为，是他的自由选择，即：他原本可以在那一刻作出其他选择：不作出那个行为，或作出其他行为。 2）主观价值论：对价值的度量（即对世界各种状态之好与坏的评价），只能由个体自己作出，并且，不同人的度量结果之间，不具有可比性，即：其中任何一个不能以任何比例折算为另一个，因而，价值度量结果之间也不具有可加性。 3）方法论个人主义：行动或选择这个动词的主语必须是具体的个人。 这组命题对于社会科学的重要性无论如何强调都不过分，所以我很高兴能被如此重视，然而同时，我也遗憾的发现，我对这组命题的态度与这些学者有着根本的分歧；简单说，这些学者如同其他许多学者包括几年前的我一样，认为或暗示了，自由意志论或主观价值论是经验命题；而我却认为：这些命题只能被当作先验命题，这意味着，它们是武断的认定，不接受任何实证检验，也无视任何事实的挑战，不会因为任何事实发现或科学进展而改变。 我认为，一些学科（如道德哲学、伦理学、法学）以这些命题作为逻辑起点，因为是起点，本身无须加以论证，而一旦你放弃这一立场，退而将之认定为经验命题，那么这些学科的基础将被动摇。比如翟教授在他的精彩演讲最后，却打开了一个实证后门，他说（大意）：自由意志和个人主义之所以成立且难以动摇，是因为人就是一个一个的，他们的思想原本就是独立的，他们的选择必定也只能是分别作出的。 实证后门一旦打开，魔鬼就跟着来了：我们在团体操上很容易看到一个号令同时引发一群人的相似行为，你可以讨厌这种团体行动，但它们确实存在，你可以说，每个人听到号令后作出了自由选择，听从号令是他的选择，他原本也可以作出其他行为。 是的，“原本也可以”，但“原本也可以如何如何”这句话不可能用任何实证方法来证伪，它在逻辑上就直接与“实证”这个词相矛盾，因而，支持你说出“原本也可以如何如何”的，只能是一个先验而武断的观念，而不可能是经验。 正是在这一点上的混淆，导致了社会科学界对心理学和生物学的反感和抵制，这些研究行为的自然科学，把人当作实证研究的对象，试图发现人在何种条件下会作出何种行为，很明显，这些学科不可能引入自由意志这个概念，因为一旦这样做，会让它们的所有命题立刻失去实证意义，在心理学家和行为学家看来，“原本也可以”这句话不仅毫无意义，且被禁止提及。 相反，对于道德学家和法学家，自由意志是逻辑起点，假如你从别人家里拿走了一件东西，无论你为这项行为说出多少“原因”，无论你如何用经验科学论证在那种条件下你必定会那么做，法官都不会理睬。 在自然科学家眼里，人只是世界这部运转机器的一个普通部分，所谓个人意志只是因果链的一个环节，而在道德学家和法学家眼里，每个人是世界的一个“奇点”：任何因果链一旦碰上个人，立刻终结，同时，任何来自个人的因果链，此人就被认定为因果链起点，换句话说：不承认存在任何以个人为中间点的因果链。（唯一的例外是枪，只有当你用枪指着另一个人时，你才能得到一条以那个人为中间点的因果链） 这种以人为断点分割因果链的做法是人为的和武断的，用哲学黑话说就是先验的，它不以任何经验为前提，无论科学家作出多少研究，来证明被分割的因果链上的前后事件之间“其实”具有高度可信的因果关系，都不能改变这一武断假定，这就是道德哲学和经验科学的根本差异所在。 一旦你认清两种观念体系下的两个世界的这一差异，许许多多围绕这一问题而产生的纷争便迎刃而解，你可以在两个世界之间轻松切换：在不碰到人的时候，一切相安无事，而一旦碰到人，在经验科学世界里，继续把他当作普通对象看待，在道德哲学世界里，你马上掏出剪刀把因果链剪断，至于形式逻辑，哪个世界都少不了，照用无误。

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。

我在上一篇中谈论了自由意志，MiniTrue引了寄生虫通过操纵蚂蚁行为获得传播机会的例子，并问我是否认为这些蚂蚁具有自由意志？

按我对自由意志一词用法的澄清，回答是：

1）如果我准备在科学语境中说话，我绝不会提及自由意志这个词，正如我不会提及上帝这个词。

2）如果我准备在伦理学或法学语境中说话，我会说任何蚂蚁都没有自由意志，因为我们已经武断且不容置疑地认定了：只有人有自由意志。

3）如果是日常交谈，视心情和修辞需要而定，各种可能都有。

 

自由意志是伦理学和法学的基础命题，它假定个人的行为是其自由作出的选择，因而个人应对其行为的后果负责——除非能证明他受到他人暴力胁迫，从而引出了责任的概念。很明显，缺了自由意志假定，责任、过错、善恶和道德就无从谈起，整个道德和法律体系便失去了基础。

但需要强调的是，“人具有自由意志”，这是一个武断的假定（用黑话说，叫先验命题），而不是一个实证性的判断，它不接受事实检验，因而无论行为科学、心理学或脑科学如何发展、获得何种发现，都不会影响该命题。

因为不理解这一点，引出了很多关于自由和奴役的谬论。比如，有人说穷人去血汗工厂工作，这不是他的“自由选择”，因为他为了吃饱肚子“没有选择”，这么说是荒谬的。我们谈论人的自由意志时，是不考虑客观条件的，不能因为某些外部条件与某种行为的强相关性，就把它们当成为该行为开脱责任的理由。假如我们可以说一个快饿死的人的偷面包行为不是他的自由选择，那么我们同样可以说一个球迷把电视频道切换到足球节目的行为不是自由的。

实际上，人的任何行为都能找出客观原因，历史、文化、收入、基因、发育过程、教育经历，等等，按这种逻辑，没有行为是自由的，每个人都是历史和欲望的奴隶，用时髦词汇说，都是房奴、球奴、乐奴、网奴、财奴、色奴、麻将奴、时装奴、LV奴、美容奴……

正是上述荒谬逻辑，引出了积极自由和平等理论，以及专与劳工和穷人作对的劳工法和最低工资法等等副产品。

自由意志是个古老而混乱的话题，之所以混乱，是因为哲学家、法学家和科学家在谈论它时，所暗指的含义大不相同，我也是最近才理清楚其中的线索，我在今年3月的一个帖子里总结如下：

终于想到一种对休谟之叉（Hume's fork）的简洁回答了。
1）科学不可能证明或证否自由意志，因为科学预先就排除了自由意志。
注：排除自由意志不是指否定自由意志的存在，而是拒绝将这一概念引入科学的逻辑系统，因为任何引入了自由意志的系统将不具有可证伪性。
举例说明：向一个对象扔红色和蓝色两种球，每次每种颜色各一个。在科学上，下面两种说法完全等价： A）十次里有七次红球弹回来，蓝球留下，另三次相反。 B）十次里有七次对方选择蓝球，另三次选择红球。
2）伦理学和法学不可能讨论是否存在自由意志，因为它们预先就假定了自由意志，缺了这个假定，任何伦理（或道德）命题和法学命题都毫无意义。
3）推论一：上述两条合起来规定了任何科学命题不可能与一个伦理或法学命题在同一逻辑系统里共存。
4）推论二：假设经济学是一门科学，就必须排除自由意志概念，正如第一点（B）中那个“选择”必须被认为不暗示任何自由意志，经济人模型只能是一个不包含自由意志的决策机器，和把球弹回来的木板没有区别。

此前的07年8月，我在另一个帖子里，试图区分关于自由意志一词的三种用法：

第一种，科学语境中：是否有某种内在的不确定因素在影响人的行为？ ——一个实然问题。在目前科学发展的背景下，这个问题可以被另一个更狭隘的问题所代替：人脑的工作机制中是否存在量子效应的作用？
第二种，伦理学语境中：个人是否应被当作责任和规范的主体和基本单位？ ——一个应然问题。实际上和上述科学语境中的自由意志是否存在没有关系。
第三种，糊涂或不知所云语境中：人脑中是否有一个发号施令的“小人”？ ——有没有这个小人有什么关系？这个小人的是否遵循物理规律？它有没有自由意志？能否担负刑事责任？小人里还有没有小小人？

当时，我刚看到Dawkins关于决定论和自由意志的一段论述：

The validity of the determinist point of view and, separately, its bearing on an individual's moral responsibility for his actions, has been debated by philosophers and theologians for centuries past, and no doubt will be for centuries to come. I suspect that both Rose and Gould are determinists in that they believe in a physical, materiahstic basis for all our actions. So am I. We would also probably all three agree that human nervous systems are so complex that in practice we can forget about determinism and behave as if we had free will. Neurones may be amplifiers of fundamentally indeterminate physical events. The only point I wish to make is that, whatever view one takes on the question of determinism, the insertion of the word 'genetic' is not going to make any difference. If you are a full-blooded determinist you will believe that all your actions are predetermined by physical causes in the past, and you may or may not also believe that you therefore cannot be held responsible for your sexual infidelities. But, be that as it may, what difference can it possibly make whether some of those physical causes are genetic? Why are genetic determinants thought to be any more ineluctable, or blame-absolving, than 'environmental' ones?