14 THE HISTORY OF BIOLOGY 



East — how far is not known with any certainty — and afterwards taught 

 in his native island, but on account of political disturbances he was forced 

 to migrate to the Greek colony of Croton in the south of Italy. There he 

 carried on as a research-worker and religious and social reformer until his 

 death, probably about the year 500 b.c. His dates are in any case highly 

 uncertain and much disputed. There is no doubt that much of the wisdom 

 he taught emanated from the East; his famous theory of the wandering of 

 the soul, for instance, already existed in India long before his time, and the 

 geometrical theorem named after him had already been proved by Indian 

 mathematicians long before he lived. His cosmological theories, however, 

 are extremely interesting. He conceived fire to be the origin of matter. It 

 should be borne in mind that to the people of antiquity and to many suc- 

 ceeding generations fire was not a chemical process, but an element, like air, 

 water, and earth. Pythagoras believed that all things originated in a primor- 

 dial fire forming the centre of the cosmos. Around this primordial fire re- 

 volve all the celestial bodies, the earth, the planets, and the sun. The shape 

 of the celestial bodies is spherical and their orbits circular. This cosmology, 

 as compared with that of the lonians, represented an immense advance. 

 Through him the fact of the globular shape of the celestial bodies was in- 

 troduced into science, although it took a thousand years to penetrate the 

 consciousness of the world in general. Still more remarkable was his theory 

 of the earth as a moving, revolving body. This theory the people of antiquity 

 found it impossible to accept; ^ Copernicus was the first to take up the theory 

 anew and was actually accused by his opponents of Pythagoreanism. In 

 the sphere of mathematics Pythagoras was also a pioneer; he discovered the 

 regularity of number-series and was led by his speculations in mathematics 

 to propound the fanciful and mystical theory that numbers govern matter, 

 and even that numbers are the principle of matter. Further, he even included 

 tonal harmony in music in this mystical system of thought; his theories on 

 the "harmony of the spheres" are as well known by name as they are diffi- 

 cult to understand in substance. 



Pythagoras' influence on scientific development was very great and was 

 also considerable in the political life of his day. His disciples founded a 

 strict order, or kind of sect, which worshipped in Pythagoras a divinely 

 inspired prophet. Persecuted during the most brilliant period of Greek 

 democracy for their pronounced aristocratism, they were finally dispersed, 

 but their teachings experienced a revival in late classical times. 



"The Greeks of the West 

 With Pythagoras the nationality of western Greece assumes a place in 

 scientific history. Southern Italy as far as Naples, as well as Sicily, had been 



* Aristarchus of Samos taught, it is true, at a far later period that the sun is the centre 

 around which the earth revolves, but this theory soon fell into oblivion. 



