However, waiving the question (interesting enough in itself)--Whether upon earthly principles a fifth universal empire could by possibility arise in the present condition of knowledge for man individually, and of organization for man in general--this question waived, and confining ourselves to the comparison of those four monarchies which actually have existed,--of the Assyrian or earliest, we may remark, that it found men in no state of cohesion. This cause, which came in aid of its first foundation, would probably continue; and would diminish the _intensity_ of the power in the same proportion as it promoted its _extension_. This monarchy would be absolute only by the personal presence of the monarch; elsewhere, from mere defect of organization, it would and must betray the total imperfections of an elementary state, and of a first experiment. More by the weakness inherent in such a constitution, than by its own strength, did the Persian spear prevail against the Assyrian. Two centuries revolved, seven or eight generations, when Alexander found himself in the same position as Cyrus for building a third monarchy, and aided by the selfsame vices of luxurious effeminacy in his enemy, confronted with the self-same virtues of enterprise and hardihood in his compatriot soldiers. The native Persians, in the earliest and very limited import of that name, were a poor and hardy race of mountaineers. So were the men of Macedon; and neither one tribe nor the other found any adequate resistance in the luxurious occupants of Babylonia. We may add, with respect to these two earliest monarchies, that the Assyrian was undefined with regard to space, and the Persian fugitive with regard to time. But for the third--the Grecian or Macedonian--we know that the arts of civility, and of civil organization, had made great progress before the Roman strength was measured against it. In Macedon, in Achaia, in Syria, in Asia Minor, in Egypt,--every where the members of this empire had begun to knit; the cohesion was far closer, the development of their resources more complete; the resistance therefore by many hundred degrees more formidable: consequently, by the fairest inference, the power in that proportion greater which laid the foundations of this last great monarchy. It is probable, indeed, both _à priori_, and upon the evidence of various facts which have survived, that each of the four great empires successively triumphed over an antagonist, barbarous in comparison of itself, and each _by_ and through that very superiority in the arts and policy of civilization.