84 A SHORT HISTORY OF SCIENCE 



and also with that other branch of mathematics, which, closely con- 

 nected as it is with the science of the heavens, we very absurdly call 

 geometry, the measurement of the earth.' 



Aristotle's writings include not merely works on scientific sub- 

 jects, but treatises of the very first importance On Poetry, On 

 Rhetoric, On Metaphysics, On Ethics, and On Politics. Besides 

 his scientific works mentioned above, there are others entitled 

 On Generation and Destruction, On the Parts of Animals, 

 On Generation of Animals, Researches about Animals, On the 

 Locomotion of Animals. One of the most important of his 

 many services to science is the encyclopedic character of his 

 writings, since from time to time he reviews in them the 

 opinions of his predecessors whose works are sometimes known to 

 us chiefly through his references to them. While standing thus 

 upon the shoulders of the past, he shows at the same time both 

 vast learning and much originality. He may be truly called the 

 founder of zoology. 



Of Aristotle's contributions to science, the greatest was un- 

 questionably that spirit of curiosity, of inquiry, of scepticism, and 

 of veracity which he brought to bear on everything about him 

 and within him. His observations are often poor, his conclu- 

 sions often erroneous, but his interest, his curiosity, his zeal are 

 indefatigable. 



THEOPHRASTUS. One of Aristotle's principal pupils, and his 

 successor in his School, was Theophrastus (372-287 B.C.) notable 

 in the history of science chiefly as an early student of plants, 

 and writer of the most important treatises of antiquity on botany. 

 These were two large works, one of ten books and the other of 

 eight, On the History of Plants, and On the Causes of Plants, 

 respectively. In these, more than 500 species of plants are de- 

 scribed, chiefly with reference to their medicinal uses. It is es- 

 pecially interesting to note that Theophrastus recognized the 

 existence of sex in plants, though he does not appear to have 

 known the sex organs. 



EPICURUS AND EPICUREANISM. A few words may be said of 

 another philosopher of the fourth century, a follower to some 



