We have quoted, in an earlier part of this chapter, a striking passage from Demosthenes, embodying that view of the objective validity of law under which alone political institutions can be secure. "That is law," said the orator, "which all men ought to obey for many reasons, and especially because every law is an invention and gift of the gods, a resolution of wise men, a correction of errors intentional and unintentional, a compact of the whole state, according to which all who belong to the state ought to live." That is the conception of law which the citizens of any stable state must be prepared substantially to accept, for it is the condition of that fundamental belief in established institutions which alone can make it worth while to adapt and to improve them. It was, accordingly, the conception tacitly, at least, accepted in Greece, during the period of her constructive vigour. But it is a conception constantly open to attack. For law, at any given moment, even under the most favourable conditions, cannot do more than approximate to its own ideal. It is, at best, but a rough attempt at that reconciliation of conflicting interests towards which the reason of mankind is always seeking; and even in well-ordered states there must always be individuals and classes who resent, and rightly resent it, as unjust. But the Greek states, as we have seen, were not well-ordered; on the contrary, they were always on the verge, or in the act, of civil war; and the conception of law, as "a compact of the whole state, according to which all who belong to the state ought to live," must have been, at the least, severely tried, in cities permanently divided into two factions, each intent not merely on defeating the other, but on excluding it altogether from political rights. Such conditions, in fact, must have irresistibly suggested the criticism, which always dogs the idea of the state, and against which its only defence is in a perpetual perfection of itself--the criticism that law, after all, is only the rule of the strong, and justice the name under which they gloze their usurpation. That is a point of view which, even apart from their political dissensions, would hardly have escaped the subtle intellect of the Greeks; and in fact, from the close of the fifth century onwards, we find it constantly canvassed and discussed. The mind of Plato, in particular, was exercised by this contention; and it was, one may say, a main object of his teaching to rescue the idea of justice from identification with the special interest of the strong, and re-affirm it as the general interest of all. For this end, he takes occasion to state, with the utmost frankness and lucidity, the view which it is his intention to refute; and consequently it is in his works that we find the fullest exposition of the destructive argument he seeks to answer.