176 COSMOS. 



great scientific institution which owes its origin to the first of 

 the Ptolemies long enjoyed, among other advantages, that of 

 being able to give a free scope to the differently directed pur- 

 suits of its members, and thus, although founded in a foreign 

 country, and surrounded by nations of different races, it could 

 still preserve the characteristics of the Greek acuteness of 

 mind and a Greek mode of thought. 



A few examples must suffice, in accordance with the spirit 

 and form of the present work, to show how experiments and 

 observations, under the protecting influence of the Ptolemies, 

 acquired their appropriate recognition as the true sources of 

 knowledge regarding celestial and terrestrial phenomena, and 

 how, in the Alexandrian period, a felicitous generalization of 

 views manifested itself conjointly with a laborious accumula- 

 tion of knowledge. Although the different Greek schools of 

 philosophy, when transplanted to Lower Egypt, gave occasion, 

 by their Oriental degeneration, to many mythical hypotheses 

 regarding nature and natural phenomena, mathematics still 

 constituted the firmest foundation of the Platonic doctrines 

 inculcated in the Alexandrian Museum ;* and this science 

 comprehended, in the advanced stages of its development, pure 

 mathematics, mechanics, and astronomy. In Plato's high ap- 

 preciation of mathematical development of thought, as well 

 as in Aristotle's morphological views, which embraced all or- 

 ganisms, we discover the germs of the subsequent advances of 

 physical science. They became the guiding stars which led 

 the human mind through the bewildering fanaticism of the 

 Dark Ages, and prevented the utter destruction of a sound 

 and scientific manifestation of mental vigor. 



The mathematician and astronomer, Eratosthenes of Cy- 

 rene, the most celebrated of the Alexandrian librarians, em- 

 ployed the materials at his command to compose a system of 

 universal geography. He freed geography from mythical le- 

 gends, and, although himself occupied with chronology and 

 history, separated geographical descriptions from that admix- 

 ture of historical elements with which it had previously been 

 not ungracefully embodied. The absence of these elements 

 was, however, satisfactorily compensated for by the introduc- 



* Fries, GeschicJite der Philosophic, bd. ii., s. 5 ; and the same au- 

 thor's Lehrbuch der Natitrlehre, th. i., s. 42. Compare, also, the con- 

 siderations on the influence which Plato exercised on the foundation 

 of the experimental sciences by the application of mathematics, in 

 Brandis, Geschtehte der Grieeki*ch-Romischen Philosophies, th. ii.,. abth 

 i., s. 276. 



