Diane Coyle*1が自ブログでアルフレッド・マーシャルの「Elements of the Economics of Industry」の一節を引用している(H/T Economist's View;「ミクロ的基礎付けについて(On Microfoundations)」と題したエントリでその引用を孫引きしている)。同書の全文がこちらで公開されているので、そこから該当の段落を(Coyleが省略した部分も含めて)引用すると次の通り。

The earlier English economists paid almost exclusive attention to the motives of individual action. But it must not be forgotten that economists,like all other students of social science, are concerned with individuals chiefly as members of the social organism. As a cathedral is something more than the stones of which it is built, as a person is something more than a series of thoughts and feelings, so the life of society is something more than the sum of the lives of its individual members. It is true that the action of the whole is made up of that of its constituent parts; and that in most economic problems the best starting point is to be found in the motives that affect the individual, regarded not indeed as an isolated atom, but as a member of
some particular trade or industrial group; but it is also true, as German writers have well urged, that economics has a great and an increasing concern in motives connected with the collective ownership of property and the collective pursuit of important aims. Many new kinds of voluntary association are growing up under the influence of other motives besides that of pecuniary gain; and the Co-operative movement in particular is opening to the economist new opportunities of measuring motives whose action it had seemed impossible to reduce to any sort of law.

Diane Coyleは以下のようにコメントしている。

And still increasing, given the public good characteristics of digital goods. The problem of aggregation seems to me an important one, rarely discussed, and exactly where the rational expectations revolution and real business cycle theory went wrong. It isn’t only a question of heterogeneity. There’s the fundamental question raised here by Marshall, that you don’t simply add up individual preferences or outcomes to get aggregate versions.

昔、全体と要素の中間概念ないし統合概念としてアーサー・ケストラーが提唱した「ホロン」という言葉、およびその著書「ホロン革命」(原題は「Janus: A Summing Up」)が流行ったことがあったが、今の経済学にもそうした革命が必要とされているのかもしれない。


*2:ちなみにこちらの論文では部分的に「経済学原理 2」における訳が紹介されている。