POST-SOCRATIC SCIENCE AT ATHENS 



ment would be nearer the truth. Aristotle did, in- 

 deed, bring together a great mass of facts regarding 

 animals in his work on natural history, which, being 

 preserved, has been deemed to entitle its author to be 

 called the " father of zoology." But there is no reason 

 to suppose that any considerable portion of this work 

 contained matter that was novel, or recorded observa- 

 tions that were original with Aristotle ; and the classi- 

 fications there outlined are at best but a vague fore- 

 shadowing of the elaboration of the science. Such as 

 it is, however, the natural history stands to the credit 

 of the Stagirite. He must be credited, too, with a 

 clear enunciation of one most important scientific 

 doctrine namely, the doctrine of the spherical figure 

 of the earth. We have already seen that this theory 

 originated with the Pythagorean philosophers out in 

 Italy. We have seen, too, that the doctrine had not 

 made its way in Attica in the time of Anaxagoras. 

 But in the intervening century it had gained wide cur- 

 rency, else so essentially conservative a thinker as 

 Aristotle would scarcely have accepted it. He did 

 accept it, however, and gave the doctrine clearest and 

 most precise expression. Here are his words : 2 



" As to the figure of the earth it must necessarily be 

 spherical. ... If it were not so, the eclipses of the moon 

 would not have such sections as they have. For in the 

 configurations in the course of a month the deficient 

 part takes all different shapes; it is straight, and con- 

 cave, and convex; but in eclipses it always has the line 

 of divisions convex; wherefore, since the moon is 

 eclipsed in consequence of the interposition of the earth, 



