HISTORY OF SCIENTIFIC INSTRUCTION. 373 



among the peoples occupying the Kile Valley and Chaldea, say 

 6000 b. c. 



But this study had to do with the fixing of the length of the year, 

 and the determination of those times in it in which the various 

 agricultural operations had to be performed. These were related 

 strictly to the rise of the Nile in one country and of the Euphrates 

 in the other. All human activity was, in fact, tied up with the move- 

 ments of the sun, moon, and stars. These, then, became the gods of 

 those early peoples, and the astronomers, the seers, were the first 

 priests; revered by the people because as interpreters of the celestial 

 powers they were the custodians of the knowledge which was the 

 most necessary for the purposes of life. 



Eudemus of Rhodes, one of the principal pupils of Aristotle, in 

 his History of Geometry, attributes the origin of geometry to the 

 Egyptians, " who were obliged to invent it in order to restore the 

 landmarks which had been destroyed by the inundation of the Nile," 

 and observes " that it is by no means strange that the invention of 

 the sciences should have originated in practical needs." * The new 

 geometry was brought from Egypt to Greece by Thales three hun- 

 dred years before Aristotle was born. 



When to astronomy and geometry we add the elements of medi- 

 cine and surgery, which it is known were familiar to the ancient 

 Egyptians, it will be conceded that we are, in those early times, face 

 to face with the cultivation of the most useful branches of science. 



Now, although the evidence is increasing day by day that Greek 

 science was Egyptian in its origin, there is no doubt that its cultiva- 

 tion in Greece was more extended, and that it was largely developed 

 there. One of the most useful and prolific writers on philosophy and 

 science who has ever lived, Aristotle, was born in the fourth century 

 b. c. From him, it may be said, dates a general conception of science 

 based on observation as differing from experiment. If you wish to 

 get an idea of the science of those times, read his writings on Physics 

 and on the Classification of Animals. All sought in Aristotle the 

 basis of knowledge, but they only read his philosophy; Dante calls 

 him the " master of those who know." f 



Why was Aristotle so careful, to treat science as well as philoso- 

 phy, with which his master, Plato, had dealt almost exclusively? 



The answer to this question is of great interest to our present 

 subject. The late Lord Playfair % in a pregnant passage suggests 

 the reason, and the later history of Europe shows, I think, that he is 

 right. 



" We find that just as early nations became rich and prosperous, 



* Greek Geometry from Thales to Euclid, p. 2. Allman. 



f Inferno, canto iv, p. 130 et seq. % Subjects of Social Welfare, p. 206. 



