Later, toward the end of the fifth century, it became a definite ethico-economic doctrine of the philosophers, as a criticism of their times, and as an appeal to what was deemed to be the more healthful life of the earlier days.
Plato does not devote so much attention to this theme as do Xenophon and Aristotle. His standpoint, however, is practically the same, though his tendency toward the physiocratic error is not so marked. In his second state, he orders that agriculture shall be the only means of money-making,123 and he even strikes the modern note of conservation, in his directions for the care of land, waters, springs, and forests.124 On this point, he and the other Greek thinkers accord well with the economy of the past decade with its urgent preachment, “Back to the land,” though the modern watchword has, of course, a more economic emphasis.
Capital.—Though the function of capital, aside from natural resources, was a familiar fact in the Athenian life of the fifth and fourth centuries B.C.,125 there is scarcely any consideration of it by the theorists before Aristotle. Plato has no definition of capital, nor indeed scarcely any recognition of the fact of its existence.126 His emphasis on the virtue of economy, however, and his criticism of those who spend the “stored wealth,” imply the idea that wealth should be used not merely for enjoyment, but also for productive purposes.127 His strictures upon interest show that he has but slight appreciation of the productive function of money-capital.128
Labor and industry.—On the other hand, Plato has considerable insight into the rôle of labor in production. To be sure, he shares with the other philosophers a certain prejudice against manual labor as degrading to freemen.129 The mechanical arts call forth reproach.130 Free citizens should not be burdened with such ignoble occupations,131 and any person who disobeys this rule shall lose his civic rights until he gives up his trade.132 Agriculture alone shall be open to them, and only so much of this as will not