From the account I have given of Aristotle's philosophy, it may be seen that he occupied a middle ground between the speculation of the old philosophy and the strict science of the Alexandrian school. He is the true connecting link, in the history of European intellectual progress, between philosophy and science. Under his teaching, and the material tendencies of the Macedonian campaigns, there arose a class of men in Egypt who gave to the practical a development it had never before attained; for that country, upon the breaking up of Alexander's dominion, B.C. 323, falling into the possession of Ptolemy, that general found himself at once the depositary of spiritual and temporal power. Of the former, it is to be remembered that, though the conquest by Cambyses had given it a severe shock, it still not only survived, but displayed no inconsiderable tokens of strength. Indeed, it is well known that the surrender of Egypt to Alexander was greatly accelerated by hatred to the Persians, the Egyptians welcoming the Macedonians as their deliverers. In this movement we perceive at once the authority of the old priesthood. It is hard to tear up by the roots an ancient religion, the ramifications of which have solidly insinuated themselves among a populace. That of Egypt had already been the growth of more than three thousand years. The question for the intrusive Greek sovereigns to solve was how to co-ordinate this hoary system with the philosophical scepticism that had issued as the result of Greek thought. With singular sagacity, they saw that this might be accomplished by availing themselves of Orientalism, the common point of contact of the two systems; and that, by its formal introduction and development, it would be possible not only to enable the philosophical king, to whom all the pagan gods were alike equally fictitious and equally useful, to manifest respect even to the ultra-heathenish practices of the Egyptian populace, but, what was of far more moment, to establish an apparent concord between the old sacerdotal Egyptian party--strong in its unparalleled antiquity; strong in its reminiscences; strong in its recent persecutions; strong in its Pharaonic relics, regarded by all men with a superstitious or reverent awe--and the free-thinking and versatile Greeks. The occasion was like some others in history, some even in our own times; a small but energetic body of invaders was holding in subjection an ancient and populous country. [Sidenote: The Museum of Alexandria.] [Sidenote: Establishment of the worship of Serapis.]