【メモ】 F. A. Hayek, "Notes on the Evolution of Systems of Rules of Conduct"

個人用メモ。例の如くページ番号はStudies in Philosophy, Politics, and Economics (1967)のもの。

"If there exist recurrent and persistent structures of a certain type (i.e., showing a certain order), this is due to the elements responding to external influences which they are likely to encounter in a manner which brings about the preservation or restoration of this order; and on this, in turn, may be dependent the chances of the individuals to preserve themselves.
From any given set of rules of conduct of the elements will arise a steady structure (showing 'homeostatic' control) only in an environment in which there prevails a certain possibility of encountering the sort of circumstances to which the rules of conduct are adapted. A change of environment may require, if the whole is to persist, a change in the order of the group and therefore in the rules of conduct of the individuals; and a a spontaneous change of the rules of individual conduct and of the resulting order may enable the group to persist in circumstances which, without such change, would have led to its destruction." (p.71)

ハイエクの集団淘汰論が簡明に述べられた箇所。なんらかのパターンないし構造が繰り返し出現するのを観察するならば、それはその構造が自己を環境に適用させようとしている結果に違いない。その構造を構成する要素の存在もまた、その構造の存続に依存している。

"Although the existence and preservation of the order of actions of a group can be accounted for only from the rules of conduct which individuals obey, these rules of conduct have developed because the individuals have been living in groups whose structures have gradually changed. In other words, the properties of the individuals which are significant for the existence and preservation of the group, and through this also for the existence and preservation of the individuals themselves, have been shaped by the selection of those individuals from the individuals living in groups which at each stage of evolution of the group tended to act according to such rules as made the group more efficient." (p.72)

ハイエク研究でよく話題になる、方法論的個人主義と集団淘汰論の整合性について。ここを読む限り、「方法論」と「存在論」を区別すべしと言う渡辺幹雄氏の指摘（『ハイエクと現代リベラリズム : 「アンチ合理主義的リベラリズム」の諸相』）は概ね妥当するように見える。個人の認識や行動が、集団・全体の効率性や存続に依存している以上、集団への論及抜きの方法論的個人主義は有り得ない。ただ、集団を安易に実体的な「存在」として捉えてしまうと、ヘーゲル＝マルクス的な擬人的ホーリズムに繋がる恐れがあるので、できれば「存在論」という呼称は避けた方がいい気がする。

さらに敷衍。
"Societies differ from simpler complex structures by the fact that their elements are themselves complex structures whose chance to persist depends on (or at least is improved by) their being part of the more comprehensive structure. We have to deal here with integration on at least two different levels, with on the one hand the more comprehensive order assisting the preservation of ordered structures on the lower level, and, on the other, the kind of order which on the lower level determines the regularities of individual conduct assisting the prospect of the survival of the individual only through its effect on the overall order of the society. (...)
This implies a sort of inversion of the relation between cause and effect in the sense that the structures possessing a kind of order will exist because the elements do what is necessary to secure the persistence of that order. The 'final cause' or 'purpose', i.e., the adaptation of the parts to the requirements of the whole, becomes a necessary part of the explanation why structures of the kind exist: we are bound to explain the fact that the elements behave in a certain way by the circumstance that this sort of conduct is most likely to preserve the whole – on the preservation of which depends the preservation of the individuals, which would therefore not exist if they did not behave in this manner. A 'teleological' explanation is thus entirely in order so long as it does not imply design by a maker but merely the recognition that the kind of structure would not have perpetuated itself if it did not act in a manner likely to produce certain effects, and that it has evolved through those prevailing at each stage who did." (p.76-77)

ここさえ読めばハイエクの文化的進化論のエッセンスは掴めるだろう。

最後に、一番好きな箇所。
"Man does not so much choose between alternative actions according to their known consequences as prefer those the consequences of which are predictable over those the consequences of which are unknown. What he most fears, and what puts him in a state of terror when it has happened, is to lose his bearing and no longer know what to do. Though we all tend to associate conscience with the fear of blame or punishment by another will, the state of mind which it represents is psychologically little different from the alarm experienced by somebody who, while manipulating a powerful and complicated machinery, has inadvertently pulled the wrong levers and thereby produced wholly unexpected movements. The resulting feeling that something dreadful is going to happen because one has infringed rules of conduct is but one form of the panic produced when one realizes that one has entered an unknown world. A bad conscience is the fear of the dangers to which one has thus exposed oneself by having left the known path and entered such an unknown world. The world is fairly predictable only so long as one adheres to the established procedures, but it becomes frightening when one deviates from them.
In order to live successfully and to achieve one's aims within a world which is only very partially understood, it is therefore quite as important to obey certain inhibiting rules which prevent one from exposing oneself to danger as to understand the rules on which this world operates. Taboos or negative rules acting through the paralysing action of fear will, as a kind of knowledge of what not to do, constitute just as significant information about the environment as any positive knowledge of the attributes of the objects of this environment. While the latter enables us to predict the consequences of particular actions, the former just warns us not to take certain kinds of action. At least so long as the normative rules consist of prohibitions, as most of them probably did before they were interpreted as commands of another will, the 'Thou shalt not' kind of rule may after all not be so very different from the rules giving us information about what it is.*20" (p.80-81)

*20 The possibility contemplated here is not that all normative rules can be interpreted as descriptive or explanatory rules, but that the latter may be meaningful only within a framework of a system of normative rules.