This he repeats again and again; e.g.in the Republic, or in the Laws where, casting a glance back on the Republic, he admits that the perfect state of communism and philosophy was impossible in his own age, though still to be retained as a pattern.
The same doubt is implied in the earnestness with which he argues in the Republic that ideals are none the worse because they cannot be realized in fact, and in the chorus of laughter, which like a breaking wave will, as he anticipates, greet the mention of his proposals; though like other writers of fiction, he uses all his art to give reality to his inventions.

When asked how the ideal polity can come into being, he answers ironically, 'When one son of a king becomes a philosopher'; he designates the fiction of the earth-born men as 'a noble lie'; and when the structure is finally complete, he fairly tells you that his Republic is a vision only, which in some sense may have reality, but not in the vulgar one of a reign of philosophers upon earth.

It has been said that Plato flies as well as walks, but this falls short of the truth; for he flies and walks at the same time, and is in the air and on firm ground in successive instants.
Niebuhr has asked a trifling question, which may be briefly noticed in this place--Was Plato a good citizen?
If by this is meant, Was he loyal to Athenian institutions ?--he can hardly be said to be the friend of democracy: but neither is he the friend of any other existing form of government; all of them he regarded as 'states of faction' (Laws); none attained to his ideal of a voluntary rule over voluntary subjects, which seems indeed more nearly to describe democracy than any other; and the worst of them is tyranny.

The truth is, that the question has hardly any meaning when applied to a great philosopher whose writings are not meant for a particular age and country, but for all time and all mankind.

The decline of Athenian politics was probably the motive which led Plato to frame an ideal State, and the Republic may be regarded as reflecting the departing glory of Hellas.