CLASSICAL ANTIQUITY, MIDDLE AGES 13 



that the city of Thales and Anaximander disappears for ever from cultural 

 history. Their theories, however, had been widely dispersed, and when the 

 Asiatic Greeks lost their cultural supremacy, philosophers and philosophic 

 schools were already to be found scattered throughout the world of Greek 

 culture. 



Thus Diogenes of Apollonia, in Crete, is regarded as one of the Ionian 

 school of philosophy. He lived in the first half of the fifth century and is not 

 to be confused with the more famous Cynic Diogenes, who lived in the time 

 of Alexander the Great. His explanation of the universe is based on An- 

 aximenes' theory of air as the primary matter. Out of the air are formed all 

 other elements in the world through a process of condensation. He conceives 

 life to consist of warm air moving like currents through the veins and thus 

 preserving the strength in the body. Diogenes has described the ramifications 

 of the venous system in man, or rather in mammals, and this description is 

 still partially extant — the earliest anatomical work known. For the rest, 

 we know of Diogenes that he conceived living beings to have been produced 

 out of the earth through the influence of solar heat — that is to say, a fur- 

 ther development of Anaximander's theory. Also, he believed that the 

 embryo in the uterus was developed by the warmth of the mother out of 

 the semen of the father. His embryological statements must therefore, like 

 his anatomical ideas, have been based on dissection. A contemporary of 

 his was Hippo, who is also said to have engaged in embryological research. 

 Unfortunately we know very little about him; we are not even certain of his 

 birthplace, which some say was the Isle of Samos and others Rhegium, in 

 the south of Italy. His reputation as a philosopher seems to have been in- 

 ferior to his fame as a naturalist, which is largely the reason for his having 

 been almost forgotten. He is said to have maintained Thales' theory of 

 water as the origin of matter. 



This survey of the old Ionic natural philosophy shows that there was a 

 serious attempt made to discover a natural connexion in the events of earth, 

 in the existence, origin, and decay of matter. However, partly through the 

 adoption and development of its ideas and partly through fresh influences 

 from the East, there grew up side by side with it other lines of thought, hav- 

 ing in some ways a deeper vision of the phenomena of life, but at the same 

 time also a tendency to mysticism and fanciful ideas which had been foreign 

 to the Ionian philosophers. Although it was not particularly interested in 

 biological research, it is necessary here to mention the Pythagorean philoso- 

 phy, owing to the important part it plays in the history of culture in general. 

 Its founder, Pythagoras, is one of the most extraordinary figures in cultural 

 history. Scientist, religious prophet, and statesman, mathematician, and mys- 

 tic all in one, he has become in the tradition of posterity a purely legendary 

 figure. Born in Samos off the coast of Asia Minor, he travelled widely in the 



