And of the influence of climate and temperature in forming the nature of man (a conception perhaps pressed too far in modern days when the 'race theory' is supposed to be a sufficient explanation of the Hindoo, and the latitude and longitude of a country the best guide to its morals {188}) Aristotle is completely unaware. I do not allude to such smaller points as the oligarchical tendencies of a horse-breeding country and the democratic influence of the proximity of the sea (important though they are for the consideration of Greek history), but rather to those wider views in the seventh book of his Politics, where he attributes the happy union in the Greek character of intellectual attainments with the spirit of progress to the temperate climate they enjoyed, and points out how the extreme cold of the north dulls the mental faculties of its inhabitants and renders them incapable of social organisation or extended empire; while to the enervating heat of eastern countries was due that want of spirit and bravery which then, as now, was the characteristic of the population in that quarter of the globe. Thucydides has shown the causal connection between political revolutions and the fertility of the soil, but goes a step farther and points out the psychological influences on a people's character exercised by the various extremes of climate--in both cases the first appearance of a most valuable form of historical criticism. To the development of Dialectic, as to God, intervals of time are of no account. From Plato and Aristotle we pass direct to Polybius. The progress of thought from the philosopher of the Academe to the Arcadian historian may be best illustrated by a comparison of the method by which each of the three writers, whom I have selected as the highest expressions of the rationalism of his respective age, attained to his ideal state: for the latter conception may be in a measure regarded as representing the most spiritual principle which they could discern in history. Now, Plato created his on a priori principles: Aristotle formed his by an analysis of existing constitutions; Polybius found his realised for him in the actual world of fact. Aristotle criticised the deductive speculations of Plato by means of inductive negative instances, but Polybius will not take the 'Cloud City' of the Republic into account at all. He compares it to an athlete who has never run on 'Constitution Hill,' to a statue so beautiful that it is entirely removed from the ordinary conditions of humanity, and consequently from the canons of criticism.