Wisdom always makes men fortunate: for by wisdom no man could ever err, and therefore he must act rightly and succeed, or his wisdom would be wisdom no longer.
Thus rhetoric, it seems, is a producer of persuasion for belief, not for instruction in the matter of right and wrong ... And so the rhetorician's business is not to instruct a law court or a public meeting in matters of right and wrong, but only to make them believe.
Their military training will ensure success in war, but they must maintain unity by not allowing the state to grow to large, and by ensuring that the measures for promotion and demotion from one class to another are carried out. Above all they must maintain the educational system unchanged; for on education everything else depends, and it is an illusion to imagine that mere legislation without it can effect anything of consequence.
It was Plato, according to Sosigenes, who set this as a problem for those concerned with these things, through what suppositions of uniform and ordered movements the appearances concerning the movements of the wandering heavenly bodies could be preserved.