The first one to be considered is that of Plato. No one could better express than did he the fact that a society is stably organized when each individual is doing that for which he has aptitude by nature in such a way as to be useful to others (or to contribute to the whole to which he elongs); and that it is the business of education to discover these aptitudes and progressively to train them for social use. Much which has been said so far is borrowed from what Plato first consciously taught the world. But conditions which he could not intellectually control led him to restrict hese ideas in their application. He never got any conception of the indefinite plurality of vities which may characterize an individual and a social group, and consequently limited his view to a limited number of classes of capacities and of social arrangements.

(Dewey, ch7)