Epitome of the Pi'ogress of JVatural Science, 99 



many arduous journeys in the east, undertaken through the pure 

 love of philosophy, he retired to Crotona, in Italy. As Thales, the 

 chief of the Ionian school, devoted all his attention to the discov- 

 ery of a first principle, independently of experiments by way of 

 induction, so Pythagoras endeavoured to discover the same prin- 

 ciple in the power of numbers. Pythagoras is deemed to have 

 preceded, to a certain extent, Copernicus, in the received opinions 

 respecting planetary motions. 



Herodotus, Xenophon, Hippocrates, Ctesias, and other philoso- 

 phers who flourished about these times, were contributors to 

 natural science. Herodotus, the earliest prose writer among the 

 Greeks, had travelled extensively in the east, and in Egypt. He 

 described the crocodile, and other animals of that country, with 

 much accuracy. Xenophon was born thirty-nine years later than 

 Socrates, and was one of his pupils. He was at once a soldier, a 

 statesman, and a naturalist ; was the declared enemy of the my- 

 thology of the Greeks, and taught a system of pure idealism, in- 

 cluding all things in the divinity. In the Cynegetics, which is a 

 treatise on hunting, he treats of the different races of dogs, and 

 of the various kinds of game pursued by hunters: the retreats 

 of wild beasts, their stratagems to elude pursuit, and their means 

 of defence, are there described. It is in this work we learn that 

 lions, panthers, jackals, and other species of wild beasts now 

 found in hot climates onlv, were the inhabitants of Macedonia; 

 an interesting zoological fact, bearing upon the speculations of 

 some modern naturalists. Hippocrates and Ctesias belonged to 

 the caste of the Asclepiades. In the pathological knowledge of 

 diseases, in diagnostics, and in medical treatment, the first has 

 acquired a great reputation, to which his fanciful and very de- 

 ficient mode of considering anatomy and physiology, have not 

 contributed. Ctesias was made a prisoner on the memorable ex- 

 pedition of the ten thousand, and resided, in the quality of 

 physician, seventeen years at the Persian court. In an account 

 of India, which he borrows from the Persian writers, he mentions 

 the elephant, an animal at that time unknown to the Greeks. 

 His work, however, is full of absurd stories ; he describes em- 

 blematic animals as real ones, and the fabulous stories of the 

 flying griffin, the unicorn, &c. &c., are probably due to him. 



Leucippus, the founder of the atomistic school, taught that 

 every thing was matter and motion : he was a pure materialist, 



