Mr Buckle, in his attempt to establish a universal theory that heat and moisture inevitably engender civilization, and that without those combined agencies no civilization can arise, somewhat overreaches himself. "In America, as in Asia and Africa," he says, "all the original civilizations were seated in hot countries; the whole of Peru, proper, being within the southern tropic, the whole of Central America and Mexico within the northern tropic." The fact is, that Cuzco, the capital city of the Incas, is in the cordilleras, three hundred miles from and eleven thousand feet above the sea. For the latitude the climate is both cold and dry. The valley of Mexico is warmer and moister, but cannot be called hot and humid. Palenque and Copan approach nearer Mr Buckle's ideal than Cuzco or Mexico, being above the tierra caliente proper, and yet in a truly hot and humid climate. The Hawaiian Islands,--an isolated group of lava piles, thrown up into the trade winds on the twentieth parallel, and by these winds deluged on one side with rain, while the other is left almost dry, with but little alluvial soil, and that little exceedingly fertile,--at the time of their discovery by Captain Cook appeared to have made no inconsiderable advance toward feudalism. Systems of land tenure and vassalage were in operation, and some works for the public weal had been constructed. Here were the essentials for a low order of improvement such as was found there, but which never, in all probability, would have risen much higher. Again, Mr Buckle declares that, "owing to the presence of physical phenomena, the civilization of America was, of necessity, confined to those parts where alone it was found by the discoverers of the New World." An apparently safe postulate; but, upon any conceivable hypothesis, there are very many places as well adapted to development as those in which it was found. Once more: "The two great conditions of fertility have not been united in any part of the continent north of Mexico." When we consider what it is, namely, heat and humidity, upon which Mr Buckle makes intellectual evolution dependent, and that not only the Mexican plateau lacked both these essentials, in the full meaning of the term, but that both are found in many places northward, as for instance, in some parts of Texas and in Louisiana, a discrepancy in his theory becomes apparent. "The peculiar configuration of the land," he continues, "secured a very large amount of coast, and thus gave to the southern part of North America the character of an island." An island, yes, but, as M. Guyot terms it, an "aerial island;" bordered on either side by sea-coast, but by such sea-coast as formed an almost impassable barrier between the table-land and the ocean.