It would take us too far afield to discuss the diverse ways in which Plato uses his principle. We may observe in passing, however, that he applies it to war, in his interesting criticism of the citizen-soldier;[170] to the finer arts, even when they are quite similar to each other;[171] to politics, as noted above; to justice and the moral life in general;[172] and to the intellectual life, in his unsparing criticism of the superficial versatility and dilettantism of the contemporary Athenian democracy, which trusts the government to any incompetent, professes to be able to imitate everything, and makes the many-sided Sophist (πολλαπλοῦς) the man of the hour.[173] Though he begins with the development of the principle as an economic fact, his primary interest in it is as a moral and intellectual maxim. The fact that the cobbler sticks to his last is only a symbol (εἴδωλον) of justice.[174] Nevertheless Plato does appreciate to a remarkable degree the economic bearings of the law, and his discussion of it is notably scientific and complete.[175] He sometimes pushes its application to an extreme, though such instances are perhaps meant in a playful Socratic vein.[176] At least, like Ruskin, he understands that extreme specialization must produce narrow and one-sided men, and that progress revolts against its too rigid application.[177] He is aware too that the division of labor breaks down in the case of the poor unemployed of the state, since they have no special work.[178]
Plato is not blind to the ethical aspects of the problem of slavery. In his first healthy state (ὑγιείνη), slavery and war are conspicuously absent, and it is the natural inference that the author believed these to be necessary evils of the more complex state.[179] He appreciates the dangers of absolute power, even in private life, and believes that few men can stand the strain.[180] He conceives human nature as a unity that defies absolute division into separate classes.[181] Though he does not renounce slavery in the _Republic_, he would limit, it to the barbarians and to those who seem unfit for the higher life.[182] It plays a remarkably small part in his first state, and it would seem that his idealism is here struggling against what he feels to be an economic necessity. In the _Laws_, he frankly accepts the necessity, and puts even agriculture, as well as the other industries, into the hands of slaves.[183] However, they are not to be treated as animals, but as rational men, in whom a proper usage may develop a certain degree of morality and ambition for good work.[184] To be sure, his purpose is economic rather than ethical—to make the slaves satisfied with their lot, and thus better producers.[185] He makes no mention of freedom as a reward for good behavior, though he elsewhere provides for the existence of freedmen in the state, and stipulates that they shall not become richer than their former masters.[186]