Introduction

Economical facts and practice, the actual condition of national industries, wealth, and trade, as distinguished from theories about them, have, no doubt, had a still greater influence, both on economists and philosophers ; and to estimate this effect of practice on theory would be a larger and perhaps a more important inquiry. Some writers have regarded this second inquiry as almost superseding the other, on the ground that the supreme force in human history is economicaV It is clear that we may at least go a.s far as Erdmann, who begins his chapters on Greek Philosophy with the remark that philosophy arises when the struggle for existence has given place to a life of leisure.2