道德是天生的嗎？

1. 道德是天生的嗎？

2. Innateness of morality • What does it mean to assert that human morality is innate?

3. 孟子 • 「君子所性，仁義禮智根於心。」 • （「君子表現他的本性，仁德、義行、守禮、明智都根植在心中。」） • 「惻隱之心，仁之端也；羞惡之心，義之端也；辭讓之心，禮之端也；是非之心，智之端也。人之有是四端也，猶其有四體也。」 • 「無惻隱之心，非人也；無羞惡之心，非人也；無辭讓之心，非人也；無是非之心，非人也。」

4. 荀子 • 「人之性惡，其善者偽也。今人之性，生而有好利焉，順是，故爭奪生而辭讓亡焉；生而有疾惡焉，順是，故殘賊生而忠信亡焉；生而有耳目之欲，有好聲色焉，順是， 故淫亂生而禮義文理亡焉。然則從人之性，順人之情，必出於爭奪，合於犯分亂理，而歸於曓。故必將有師法之化，禮義之道，然後出於辭讓，合於文理，而歸於治。用此觀之，然則人之性惡明矣，其善者偽也。」

5. 「人的本性是邪惡的，那些善良的行為是後天的作為。人的本性一生下來就喜好財利，依從這種本性，因此人們就產生了争搶掠奪， 謙讓的品德就消失了；一生下來就有妒忌憎恨的心理，依從這種本性，因此就產生了殘殺陷害，忠誠守信的品德就消失了，一生下來就有聲色的欲望，有喜歡美好音 樂、美色的本能，依從這種本性，因此就會產生淫蕩混亂，禮義法度就消失了。那麼，放縱人的本性，依從人的情欲，就一定導致争搶掠奪，一定跟違犯等級名分、 擾亂禮義法度的行為相合，而最終回到暴亂局面。因此一定需要師長和法席的教化，禮義的引導，這樣之後，對推辭謙讓這種美德人們才會做出，對國家的的禮法人們才會遵守，（國家）就最終走向安定太平。用這些事實看人的本性，那麼人的本性是邪惡的道理就很明顯了，那些善良的行為是人們後天的作為。」

6. 問題 • 孟子和荀子在主張道德是否天生時，所謂的「天生」指的是什麼意思？

7. 達爾文的想法 • Darwin在The Descent of Man當中，竭盡所能論述道德感(moral sense)乃是源自於群居的本能(social instincts)。 • 根據R.J. Richards(1995: 254; 1999: 142-143)，Darwin所描繪的道德感之演變發展過程可區分為四個階段：

8. 第一階段 • 原始人類在演化出一些足夠強大的群居本能之後，賴此以結合成社群。 • 這些群居的本能，極有可能是親子之間的喜好之感的延伸。 • 而如此的情感並非人類所獨有，若干動物也同樣有之。

9. “It has often been assumed that animals were in the first place rendered social, and that they feel as a consequence uncomfortable when separated from each other, and comfortable whilst together; but it is a more probable view that these sensations were first developed, in order that those animals which would profit by living in society, should be induced to live together, in the same manner as the sense of hunger and the pleasure of eating were, no doubt, first acquired in order to induce animals to eat.

10. The feeling of pleasure from society is probably an extension of the parental or filial affections, since the social instinct seems to be developed by the young remaining for a long time with their parents; and this extension may be attributed in part to habit, but chiefly to natural selection.

11. With those animals which were benefited by living in close association, the individuals which took the greatest pleasure in society would best escape various dangers, whilst those that cared least for their comrades, and lived solitary, would perish in greater numbers. With respect to the origin of the parental and filial affections, which apparently lie at the base of the social instincts, we know not the steps by which they have been gained; but we may infer that it has been to a large extent through natural selection.” (Darwin, 1871, 1: 80)

12. 親子之間的喜好之感主要來自天擇之作用，而其延伸—亦即群居本能—同樣也主要是來自天擇的作用：親子之間的喜好之感主要來自天擇之作用，而其延伸—亦即群居本能—同樣也主要是來自天擇的作用： • 當群居有利於生存時，喜好群居而結合成社群的動物在生存競爭上便占有優勢。

13. 在群居本能之中，同情的感受(sympathetic feeling)尤其重要。同情使得這些動物在其同伴受苦時也能感同身受，從而推動它們去解除其同伴的痛苦。同樣地，同情(sympathy)也並非人類所獨有，若干動物也有之。對於同情之感的起源，Darwin則是訴諸天擇之作用在社群的層級上以說明之。 • “…for those communities, which included the greatest number of the most sympathetic numbers, would flourish best, and rear the greatest number of offspring.” (1: 130)

14. 第二階段 • 社群成員一旦獲得足夠的心智能力，即使在群居本能暫時被其他衝動給凌駕而受挫的情況下，也得以事後回想起那個尚未獲得滿足的群居本能。在Darwin看來，此即良心(conscience)之起源。 • Darwin以覓食的母鳥，因順從求生本能而往南遷徙，留下嗷嗷待哺的雛鳥為例(1: 137)：雖然母鳥的求生本能一時之間凌駕其照顧雛鳥的群居本能，但由於群居本能的持久性，一旦母鳥抵達目的地而滿足其求生本能之後，若她會回想起那些被她拋棄的雛鳥，並能感同身受那些雛鳥的遭遇，她將被懊悔給折磨不已。

15. “When arrived at the end of her long journey, and the migratory instinct has ceased to act, what an agony of remorse the bird would feel, if, from being endowed with great mental activity, she could not prevent the image constantly passing through her mind, of her young ones perishing in the bleak north from cold and hunger.” (1: 137)

16. 第三階段 • 語言的發展使得社群成員能夠表達並且輕易溝通彼此的需求，甚至進一步表述成眾人在行為處事上的約定習俗。

17. 第四階段 • 社群成員逐漸養成一種習性(habit)，即在行動時會顧慮到他人之讚許與否，會在意他人的褒貶。 • 當然，什麼行為會有什麼結果，這需要根據過去的經驗以進行推理方能預計。所以在這個階段，道德感的演進同時仰賴理性與經驗。 • 藉著理性與經驗之助，社群成員愈來愈明白怎麼樣的行為真正有利於社群整體。一旦養成對於如此行為的在意與褒揚的習性之後，社群成員便會習以為常地從事有利社群整體的行為，且代代相傳。

18. Hobbes vs. Darwin • 如果我們對照T. Hobbes(1588-1679)對於道德之起源的說明，將更能看出Darwin之說法的特殊之處。 • Hobbes把人性刻劃為純粹自利(self-interest)的追求。所以，若放任人自行其是，其結果便是人人追求自利而相互爭鬥不已。如此一來，會使得個人所極欲追求的自利反而無法確保。於是，在理性的設計之下，道德才應運而生，人類文明自此進入一個全新的階段。 • Hobbes的道德起源論與Darwin之說法的不同之處有二(O. Flanagan, 2003: 382-383)：

19. “First, Darwin is more of a Humean than a Hobbesian. If we are egoists, then, for Hume as for Darwin, we are egoists with fellow-feeling. We care about the weal and woe of, at least, some others. • Second—and this follows from the first point—morality was not ‘something altogether new on the face of the earth’ at some moment in human history. According to Darwin, Homo sapiens, presumably like their extinct social ancestors, as well as certain closely related species, such as chimps and bonobos, possess instincts and emotions that are proto-moral; that is, these creatures possess the germs, at least, of such virtues as sympathy, fidelity and courage.”

20. 達爾文的道德天生論要點 • 從Darwin對於道德感之起源的說明，可歸結出以下幾點： • 道德是天生的(innate)，它非但不違反人之本性，反而是根植於人性(human nature)之中。 • 誠然，道德感的充分發展必須以足夠強的心智能力作為條件，也必須在經驗學習當中成長，但這些事實並不妨礙我們視道德為天生的，是人之天性的一部份。 • 道德是天擇的產物，是有利於生存的適應(adaptation)，有如眼、耳、鼻…等等也是有利於人之生存的適應一樣。

21. 要點二 • 值得注意的是，說道德就人類而言，乃是天生的，並非意謂每一個個別的人都具有道德感。 • 畢竟當我們說眼、耳、鼻…等等就人類而言，也是天生的時候，並非意謂每一個個別的人都具有眼、耳、鼻…等等。道德失常者或多或少總是存在，如同不幸的失明者、失聰者、失去嗅覺能力者…等等也或多或少總是存在一樣，我們並不會因此就認為他們不是人。

22. 要點三 • 另一方面，說道德是人性的一部份，並不表示道德感即為人之本質(essence)—所謂的構成人之所以為人的充分且必要的條件。 • 由於Darwin的物種演化理論並不支持任何動、植物具有所謂永恆不變動的本質，它當然不會把道德感視為人之所以為人的永恆不變動的本質。說人類的道德感是天生的、是人性的一部份，指的就是如此的道德感乃是天擇的產物，它是有利於人之生存的適應。

23. 要點四 • 再者，從演化論的觀點而言，過去的適應未必在未來也依然是適應。如果環境的變遷足夠劇烈，則過去一度是有利的適應性狀，有可能在環境的劇烈變遷之後不再是適應的性狀。而如此的說法理當也適用於人類的道德感上。

24. Joyce’s innateness of morality thesis • The process of evolution has designed us to think in moral terms, that biological natural selection has conferred upon us the tendency to employ moral concepts. • (Human capacity for making moral judgments can be given an adaptive explanation in genetic terms: the present-day existence of the trait can be explained by reference to a genotype having granted ancestors reproductive advantage.)

25. 對於IM的可能誤解 • It doesn’t follow that an innate trait will develop irrespective of the environment (for that isn’t true of any phenotypic trait), or even that it is highly canalized. • It does not follow that there is a “gene for morality.” • Nor do this conception of innateness and the references to “human nature” that routinely come with it imply any dubious metaphysics regarding a human essence. Asserting that bipedalism is innate and part of human nature doesn’t imply that it is a necessary condition for being human.

26. IM論題可強可弱 • Saying that we naturally make moral judgments may mean that we are designed to have particular moral attitudes toward particular kinds of things (for example, finding incest and patricide morally offensive), or it may mean that we have a proclivity to find something-or-other morally offensive (morally praiseworthy, etc.), where the content is determined by contingent environmental and cultural factors. • These possibilities represent ends of a continuum; thus, many intermediate positions are tenable.

27. 對於IM的質疑一 • By claiming that human morality is genetically “programmed,” one seems to deny the centrality of cultural influence, or even imply that any manifestation of morality is inevitable.

28. 回應 • With how much ease environmental factors may affect or even prevent the development of any genetically encoded trait is an empirical question. • Stephen Jay Gould was dead wrong when he wrote: “If we are programmedto be what we are, then these traits are ineluctable. We may, atbest, channel them, but we cannot change them either by will, education,or culture”

29. Phenylketonuria (PKU)（苯酮尿症）, for example, is a genetic metabolic disorder that can cause terrible mental retardation but can be easily avoided with a restricted diet; Down’s Syndrome, by comparison, is a genetic disorder about which nothing can at present be done to avoid the expression of its characteristics. • There is no general relationship between genotype and phenotypic expression. • PKU is just one clear counterexample of a trait that is genetically “programmed”in some individuals but straightforwardly preventable.

30. 對於IM的質疑二 • An evolutionary account of morality would deprive us of our freedomof will. • Patricia Williams(1993) has argued that if morality were innate then our moral judgmentswould be coerced from within, but that, since in order to be ethical beingswe must be free, it is incoherent to appeal to evolution in order to explainour ethical nature; therefore morality cannot be innate.

31. 回應 • Freedom does notinvolve the capacity to alter the course of neural causation by an act of puremental determination; it simply means acting on your desires. • Thus an evolutionaryexplanation of an action may actually amount to a clarificationof the nature of the action’s freedom, since it may well be an explanation ofwhere the relevant desires came from.

32. Human desires, after all, don’t comefrom nowhere—all desires have a history, and some of them have an evolutionaryhistory. • Everyday thinking allows that beliefs and desires arefrequently caused by environment factors without thereby counting as“coerced.” So, there is no reason to say things would stand differently if somebeliefs and desires are caused by genetic factors.

33. 對於IM的質疑三 • The hypothesis that morality is innate is undermined by observationof the great variation in moral codes across human communities.

34. 回應 • Nor need the hypothesis that morality is innate be undermined by observationof the great variation in moral codes across human communities,for the claim need not be interpreted as holding that morality with someparticular content is fixed in human nature.

35. The analogous claim thathumans have innate language-learning mechanisms does not imply thatJapanese, Italian, or Swahili is innate. • We are prepared to learn some languageor other, and the social environment determines which one.

36. Thoughthere is no doubt that the content and the contours of any morality arehighly influenced by culture, it may be that the fact that a community hasa morality at all is to be explained by reference to dedicated psychologicalmechanisms forged by biological natural selection.

37. That said, it is perfectlypossible that natural selection has taken some interest in the content ofmorality, perhaps favoring broad and general universals. • This “fixed” content would pertain to actionsand judgments that enhance fitness despite the variability of ancestralenvironments.

38. Michael Ruse • “ethics is an adaptation, put in place by our genes as selected in the struggle for life, to aid each and every one of us individually.” (1995: 257)

39. 問題 • Why would a moralsense evolve by natural selection? (Why might a moral sense be adaptive?) • How did a moral sense evolve?—What did naturalselection do to the human brain to enable moral judgment?

40. What is biological adaptation? • An adaptation, as commonly defined, is “a feature that has become prevalent in a population because of a selective advantage conveyed by that feature in the improvement in some function.” (Futuyma, 2009: G1)

41. Task Analysis • To establish that moral sense is an adapted feature, one needs to show: • (1) the function that moral sense serves; • (2) the selective advantage conveyed by moral sense in the improvement of the function that it serves; • (3) that moral sense has become prevalent in a human population because it conveys the selective advantage in the improvement of the function it serves.

42. Divided opinions on the adaptation thesis • Adaptationists: Ruse (1986; 1995) & Wilson (1986); Joyce (2006) • Anti-adaptationists: Lahti (2003); Ayala (2009); Prinz (2007; 2008)

43. Joyce • “[T]he process of evolution has designed us to think in moral terms, and biological natural selection has conferred upon us the tendency to employ moral concepts.” (2006: 3)

44. Ruse • “The point about morality (says the Darwinian) is that it is an adaptation to get us to go beyond regular wishes, desires and fears, and to interact socially with people. How does it get us to do this? By filling us full of thoughts about obligations and duties, and so forth. And the key to what is going on is that we are then moved to action, precisely because we think morality is something laid upon us. We may have choice about whether to do right and wrong, but we have no choice about right and wrong in themselves.” (1986: 253)

45. Lahti • Compared to nonhuman animals with desires and emotional tendencies, moral sense does not convey the selective advantage in the improvement of the function that it serves.

46. Prinz • Moral sense is an evolutionary by-product of human non-moral capacities: human beings are equipped with a range of non-moral tools, such as emotions, memory, rule-formation, imitation, and mind-reading, that could collectively give rise to a moral capacity. • In other words, moral sense has become prevalent not because it conveys a selective advantage in the improvement of the function it serves, but because it is a by-product of other adaptive features.

47. Lahti’s argument • Lahti pointed out, if one takes seriously the conservatism of natural selection, then one probably has difficulties in explaining why there had evolved “a biologically unprecedented mechanism for a purpose which is achieved regularly in nature by much more straightforward means.” (Lahti, 2003: 644)

48. Lahti’s argument from redundancy • (1) If moral sense were an adaptation which serves to promote the performance of human altruistic behaviors, then moral sense would have been a redundant mechanism. • (2) However, given the conservatism of natural selection, such a redundant mechanism is unlikely. • Therefore, the view that moral sense is an adaptation would probably be wrong.

49. Joyce • Question: In what way might judging oneself in moral terms benefit oneself?

50. Basic Idea • (1) An individual sincerely judging some available action in a morally positive light increases the probability that the individual will perform that action (likewise, mutatis mutandis, judging an action in a morally negative light). • (2) If reproductive fitness will be served by performance or omission of a certain action, then it will be served by any psychological mechanism that ensures or probabilifies this performance or omission (relative to mechanisms that do so less effectively).