THE Alexandrian achievement in almost all fields of scientific knowledge--in medicine, in mathematics, in mechanics, and in astronomy--has to be seen against a far longer and wider perspective than any other aspect of her civilization. In literature Alexandrian work has to be considered and evaluated in the light of the comparatively recent past of Greek poetry, and the influence upon it of earlier Egyptian and Oriental literature may be virtually disregarded; it is only in the more humble literary genres that the Egyptian background is significant. This shortness of perspective is reduced to a minimum in the field of criticism and scholarship, in which Alexandria was the virtual creator of a new subject, even if signs of a growing critical sense are apparent in the fourth century.
Science, on the other hand, if we use the term to cover all those activities which demand a specialized and systematic knowledge, be it of the human body, of numbers, or of the heavens, had had its practitioners, however modest and however misinformed at times, from an early date in recorded history, and the achievement of Greece is less pre-eminent, even if its influence on the western world has been none the less decisive. This is particularly relevant to Alexandria, for although in most fields of science that city surpassed the achievement of the Classic Greek world, and indeed that of Rome also (engineering excepted), it has to be remembered that Pharaonic Egypt had reached a high standard already by the time of the Old Kingdom, both in some aspects of medical practice and in engineering. It does not indeed follow from this that Alexandrian scientists were indebted to either earlier or contemporary Egyptian practice; there is little doubt, on the contrary, that the most striking advances made in Alexandria were in regions unexplored by Egyptian doctors and scientists: the region of inference rather than of observation. But the general perspective demands that we bear this feature in mind.
In any discussion of scientific work it is natural to think in terms of progress or advance, in a way that is not possible in respect of literature and other fine arts, where, though judgements of quality play a part, intellectual or artistic fashions and the mood of the age, the Stimmung