分類彙整:小考

小考:張五常沒有讀過《自私的基因(The Selfish Gene)》?

不怕諸君見笑,我大學本科是讀經濟的。
引發我讀經濟,而且是到薄扶林讀經濟者--張五常是也。

中五時成績欠佳,轉到一所新學校(名副其實的新學校,是當年剛剛開校的!)讀預科。空堂不少,遂到圖書館打發時間。不知何故,圖書館的張五常著作所藏甚豐,開始讀了覺得有趣,就一本接一本的讀。當時,圖書館有的(大概兩尺厚吧)都讀了一遍。(回想起來,當時還真是清閒得很。依稀記得,黃仁宇系列也是那時候讀的。)

「經濟學真有趣!」當時這麼想。當然,現在也是這麼想的。

我記得,他好像有提過Richard Dawkins《自私的基因(The Selfish Gene)》--大概中四、五時有看過中譯本,但當時應該半懂不懂的吧,我想。

當時看到的文章,他究竟是提過那本書的甚麼呢?他是怎麼說的呢?實在想不起來。不過,提這點往事,當然不是毫無理由的。

最近,隨手翻開張五常新修的《經濟解釋(神州增訂版)》,忽地發現他筆下簡述的《自私的基因》,完全不是那一回事!簡直錯得離譜!

(不用亂估了,我認,很多時買了書,未有時間細讀,只是擱在一旁;
 引發此文的那一段落,也是這樣才走漏眼的吧。)

關於經濟的問題,在此不討論,實在只是對他曲解Richard Dawkins的名作看不過眼。

我懷疑,其實他根本沒有讀過《自私的基因》吧!(我不想說他沒有「讀通」。以我看了他的書多年,也讀過一點他的論文,對他的能力絕無懷疑;疑中留情,我寧可相信他只是沒有讀過、道聽塗說。)

我讀到的段落,是這樣的:

「一九七六年,生物學家道金斯發表了《自私的基因》(R. Dawkins, The Selfish Gene),旁徵博引,用了數之不盡的例子證明「自私」是動物與生俱來,是遺傳的,不可更改。這本重要的書啟發了一門新的學問--「生物經濟學」。我的另一位老師赫舒拉發(J. Hirshleifer)是這門新學問的一個主要倡導者。十多年前他來信說,這門學問的發展大有看頭。」
(下劃線及粗體為筆者所加。)
張五常,《經濟解釋 神州增訂版‧卷一:科學說需求》。香港:花千樹,二○一一年(初版:二○○一年;神州增訂版:二○一○年),頁79。

再翻看舊書,原來舊版已經有這一段:

「一九七六年,生物學家道更斯發表了《自私的基因》(R. Dawkins, The Selfish Gene),旁徵博引,用了數之不盡的例子證明「自私」是動物與生俱來,是遺傳的,不可更改。這本重要的書啟發了一門新的學問--「生物經濟學」。我的另一位老師赫舒拉發(J. Hirshleifer)是這門新學問的一個主要倡導者。最近他來信說,這門學問的發展大有看頭。」
(下劃線及粗體為筆者所加。)
張五常,《經濟解釋‧卷一:科學說需求》,第二版。香港:花千樹,二○○二年(初版:二○○一年),頁75。

(記憶中,我是有買初版的,但一時找不到,只好用後來另買,打算放在案頭研讀那一套--原來是第二版,但內容應該大致相同的。)

除了Richard Dawkins的譯名由「道更斯」改成「道金斯」,赫舒拉發(Jack Hirshleifer)來信的日子據印刷時間相應調整,兩處;整段的內容是完全一樣的。

也就是說,由二○○一年至二○一○年,張五常對《自私的基因》這本書的看法應該是一樣的:「旁徵博引,用了數之不盡的例子證明「自私」是動物與生俱來,是遺傳的,不可更改。」

上述引文並非孤例:

「我老是想,是人體細胞內的哪些基因促成那希望傳世的意圖呢?其它動物有沒有這樣的傾向?一九七五年Richard Dawkins發表了重要的《自私的基因》(The Selfish Gene那本書,說自私是遺傳的,人類與其它動物沒有兩樣。我想,人類喜歡作品傳世與要生養後代也沒有兩樣吧。其它動物也生養後代。是因為自私的基因而生養後代嗎?還是因為生養後代是天生的機能,所以動物不能不自私了。我取後者。這樣看,人類不是因為自私而存在,而是存在的本身含意在自私的基因。由此引申,我們希望自己的作品可以傳世,不是因為自私,而是從生物本身的生養機能帶過來。讀者看得懂嗎?還是我有點老糊塗了?」
(原文為殘體中文,由筆者人手轉換作正體中文;文中別字,一字未改;而且他連《自私的基因》的出版年份都搞錯了;下劃線及粗體為筆者所加。)
張五常,<(2008.04.08)传世的基因(创作闲话,之一)>,張五常新浪博客。最後修改日期:2008年04月08日。http://blog.sina.com.cn/s/blog_47841af7010090wd.html

認真讀過《自私的基因》者,絕不會這麼說。

張五常經濟常說,學經濟要把握好「概念」;讀《自私的基因》,或許也需要如此。回想一下,經濟、生物、邏輯、科學… 我真的從《自私的基因》中學了不少。

首先要搞清楚書的題目,所謂「自私」(這概念)其實只是應用於「基因」。不過,兩個詞都要解釋一下。

先來說「自私」。

「自私」是有意識的東西才會有的,「基因」不過是一串重複、簡單的分子--一串DNA;說一段DNA有意識、有意圖,似乎太天馬行空了吧!

如果你這樣去理解,真的很天馬行空,但這根本不是書中的意思。就跟經濟學假設人是「自私」一樣,其實人是否都如此「自私」,不知道,也不重要。那不過是一項方便分析的假設而已。事實上,應該說是:無論任何生物(或類生物的東西?),只要被放在一個資源稀缺的環境,就會展現出「如同自私」一般的行為;當然會有例外,但例外就會被淘汰;那剩下來可以看到的,當然就是看起來是「自私」,或曰展現出「自私行為」那些了。

經濟學和生物學的相似之處,我不只是我說的:

“Consider, first, the simplest type of biological evolution. Plants “grow" to the sunny side of buildings not because they “want to" in awareness of the fact that optimum or better conditions prevail there but rather because the leaves that happen to have more sunlight grow 8 Also suggested is another way to divide the general problem discussed here. The process and rationale by which a unit chooses its actions so as to optimize its situation is one part of the problem. The other is the relationship between changes in the environment and the consequent observable results, i.e., the decision process of the economic society. The classification used in the text is closely related to this but differs in emphasizing the degree of knowledge and foresight. faster and their feeding systems become stronger. Similarly, animals with configurations and habits more appropriate for survival under prevailing conditions have an enhanced viability and will with higher probability be typical survivors. Less appropriately acting organisms of the same general class having lower probabilities of survival will find survival difficult. More common types, the survivors, may appear to be those having adapted themselves to the environment, whereas the truth may well be that the environment has adopted them. There may have been no motivated individual adapting but, instead, only environmental adopting."
Armen A. Alchian. “Uncertainty, Evolution, and Economic Theory." Journal of Political Economy, Vol. 58, No. 3 (Jun., 1950), pp. 211-221

這麼有趣的段落,是張五常的老師艾智仁(Armen A. Alchian)寫的。

回到《自私的基因》,說基因「自私」,是甚麼意思呢?基因本身有沒有意識?不知道,多半沒有,應該沒有,但不重要。基因有「複製」的能力,但世界只得這麼大,資源必然是稀缺的,故此會有競爭,而競爭的結果是:能存活下來的,必然是展現出「自利」、「自私」行為那些「基因」。

我一直都含糊其辭,只說「基因是一段DNA」,又是否真的符合書中意思呢?其實我是刻意為之,因為書中本就如此,最初是定義得含糊一點,後來才再說清楚。我相信這是Dawkins寫故事的方式,我當時也覺得他說得很清楚,就跟隨他的做法了。

“The definition I want to use comes from G. C. Williams. A gene is defined as any portion of chromosomal material that potentially lasts for enough generations to serve as a unit of natural selection."
Richard Dawkins. The Selfish Gene. 30th Anniversary Edition 2006. Reprint. New York: Oxford University Press, 2009. p. 28.

其實眼尖的讀者會發覺,更深層的含意已經隱含其中;但吾也愚魯,是讀到後來才越來越清楚的:

“What is the selfish gene? It is not just one single physical bit of DNA. Just as in the primeval soup, it is all replicas of a particular bit of DNA, distributed throughout the world. If we allow ourselves the licence of talking about genes as if they had conscious aims, always reassuring ourselves that we could translate our sloppy language back into respectable terms if we wanted to, we can ask the question, what is a single selfish gene trying to do? It is trying to get more numerous in the gene pool. Basically it does this by helping to program the bodies in which it finds itself to survive and to reproduce. But now we are emphasizing that ‘it’ is a distributed agency, existing in many different individuals at once. The key point of this chapter is that a gene might be able to assist replicas of itself that are sitting in other bodies. If so, this would appear as individual altruism but it would be brought about by gene selfishness."
Richard Dawkins. The Selfish Gene. 30th Anniversary Edition 2006. Reprint. New York: Oxford University Press, 2009. p. 88.

其實整本書最重要的概念,即在其中。

是,這本書是以「基因是自私的」為出發點,但實際上是要解釋:「自私的基因」怎樣推導出生物「利他」、「合作」的行為!跟張五常提到,說「自私」是「與生俱來,是遺傳的,不可更改」,大相逕庭!

而若然他有認真讀過《自私的基因》,也不會因為這本書而問:「人體細胞內的哪些基因促成那希望傳世的意圖呢?」

Dawkins的書中,有一章是說這回事的:

“But do we have to go to distant worlds to find other kinds of replicator and other, consequent, kinds of evolution? I think that a new kind of replicator has recently emerged on this very planet. It is staring us in the face. It is still in its infancy, still drifting clumsily about in its primeval soup, but already it is achieving evolutionary change at a rate that leaves the old gene panting far behind.
The new soup is the soup of human culture. We need a name for the new replicator, a noun that conveys the idea of a unit of cultural transmission, or a unit of imitation. ‘Mimeme’ comes from a suitable Greek root, but I want a monosyllable that sounds a bit like ‘gene’. I hope my classicist friends will forgive me if I abbreviate mimeme to meme If it is any consolation, it could alternatively be thought of as being related to ‘memory’, or to the French word même. It should be pronounced to rhyme with ‘cream’."
Richard Dawkins. The Selfish Gene. 30th Anniversary Edition 2006. Reprint. New York: Oxford University Press, 2009. p. 192.

這就是「meme」的起源。

在同一章,他更這麼說:

“When we die there are two things we can leave behind us: genes and memes. We were built as gene machines, created to pass on our genes. But that aspect of us will be forgotten in three generations.

But if you contribute to the world’s culture, if you have a good idea, compose a tune, invent a sparking plug, write a poem, it may live on, intact, long after your genes have dissolved in the common pool. Socrates may or may not have a gene or two alive in the world today, as G. C. Williams has remarked, but who cares? The meme-complexes of Socrates, Leonardo, Copernicus and Marconi are still going strong."
Richard Dawkins. The Selfish Gene. 30th Anniversary Edition 2006. Reprint. New York: Oxford University Press, 2009. p. 199.

所以,如果認真地讀過,而同意Dawkins的說法,或許會說:「受腦內的meme所驅使,希望其可廣為流佈,以傳後世。」

或許也是我無聊寫blog的原因吧。