_Capital._—Aristotle is the only Greek thinker who has given a clear definition of capital. After defining the slave as an instrument (ὅργανον), in order to distinguish still more sharply, he differentiates between the two kinds of wealth—that which is used for consumption, and that which is employed for further production.[591] As an example of the former, he uses the bed and the dress, and of the latter the weaver’s comb (κερκίς).[592] He points out that all wealth is produced for consumption, but that part of it is consumed indirectly in manufacture. Here is an approach to Adam Smith’s[593] definition of capital, as “that part of a man’s stock which he expects to afford him revenue.” Unfortunately, however, the Greek fails to pursue his distinction farther. The theme of his thought is, after all, not capital or production either, but the status of the slave, though, from his standpoint, the slave is capital. He proceeds with the very uneconomic assertion that life consists in action (πρᾶξις), not in production (ποίησις),[594] and concludes with the real goal of his argument, that the slave is an assistant (ὑπερέτης), or an animate instrument in the realm of action, not of production.[595] The slave is therefore an instrument to increase the life or action of his master, who himself is not represented as a producer, but as a consumer of the present stock. Thus what bids fair to be a fruitful distinction ends in a denial of the primary importance of production. The purpose of Aristotle is here similar to that in some passages of Ruskin[596] and Adam Smith,[597] to emphasize consumption rather than production.