Aristotle, perpetually engaged in the study of formal logic. Even in his much-admired criticisms on the actually existing types of government our philosopher shows practical weakness and vacillation of character. There is a good word for them all—for monarchy, for aristocracy, for middle-class rule, and even for pure democracy.[183] The fifth book, treating of political revolutions, is unquestionably the ablest and most interesting in the whole work; but when Aristotle quits the domain of natural history for that of practical suggestions, with a view to obviate the dangers pointed out, he can think of nothing better than the old advice—to be moderate, even where the constitutions which moderation is to preserve are by their very nature so excessive that their readjustment and equilibration would be equivalent to their destruction. And in fact, Aristotle’s proposals amount to this—that government by the middle class should be established wherever the ideal aristocracy of education is impracticable; or else a government in which the class interests of rich and poor should be so nicely balanced as to obviate the danger of oligarchic or democratic injustice. His error lay in not perceiving that the only possible means of securing such a happy mean was to break through the narrow circle of Greek city life; to continue the process which had united families into villages, and villages into towns; to confederate groups of cities into larger states; and so, by striking an average of different inequalities, to minimise the risk of those incessant revolutions which had hitherto secured the temporary triumph of alternate factions at the expense of their common interest. And, in fact, the spontaneous process of aggregation, which Aristotle did not foresee, has alone sufficed to remedy the evils which he saw, but could not devise any effectual means of curing, and at the same time has bred new evils of which his diagnosis naturally took no account.