In the previous books Plato has described the ideal State; now he returns to the perverted or declining forms, on which he had lightly touched at the end of Book iv. These he describes in a succession of parallels between the individuals and the States, tracing the origin of either in the State or individual which has preceded them. He begins by asking the point at which he digressed; and is thus led shortly to recapitulate the substance {cxxvi} of the three former books, which also contain a parallel of the philosopher and the State. Of the first decline he gives no intelligible account; he would not have liked to admit the most probable causes of the fall of his ideal State, which to us would appear to be the impracticability of communism or the natural antagonism of the ruling and subject classes. He throws a veil of mystery over the origin of the decline, which he attributes to ignorance of the law of population. Of this law the famous geometrical figure or number is the expression. Like the ancients in general, he had no idea of the gradual perfectibility of man or of the education of the human race. His ideal was not to be attained in the course of ages, but was to spring in full armour from the head of the legislator. When good laws had been given, he thought only of the manner in which they were likely to be corrupted, or of how they might be filled up in detail or restored in accordance with their original spirit. He appears not to have reflected upon the full meaning of his own words, 'In the brief space of human life, nothing great can be accomplished' (x. 608 B); or again, as he afterwards says in the Laws (iii. 676), 'Infinite time is the maker of cities.' The order of constitutions which is adopted by him represents an order of thought rather than a succession of time, and may be considered as the first attempt to frame a philosophy of history.