46 THE HISTORY OF BIOLOGY 



which the founder of the school had evoked disappeared entirely from their 

 circle. Instead, philosophical speculations on nature were undertaken by 

 another school of thinkers, who revived the atomic theory of Democritus, 

 which was thus given a fresh lease of life and survived not only the classical 

 period, but through the Middle Ages until the Renaissance. This new line of 

 thought was directed by Epicurus the Athenian, one of the most discussed 

 philosophical personalities of antiquity. He lived between the years 34x and 

 zji B.C., and in his native town founded a school whose members lived 

 quietly and carried out joint researches under their master's guidance. As 

 already mentioned, his theoretical standpoint was Democritus' atomic 

 theory, which he adopted without really developing it further. In direct 

 opposition to Aristotle he taught that universal space is infinite, that bodies 

 are composed of particles indivisible in themselves, whose motions are the 

 cause of everything that happens and through whose alternate association 

 and dissolution worlds arise and perish. Even the soul of man consists of 

 atoms and is thus a purely corporeal organ. There is no universal intelli- 

 gence, but all things happen through natural causes. What these causes are 

 Epicurus did not bother much about. In fact, he considered it hardly worth 

 while trying to find out the secrets of nature; thus it might well be, he ex- 

 pressly assures us, that the moon borrows light from the sun, but it might 

 equally well be self-illuminating. The main thing was that one assume a 

 natural explanation of the world and the universe; it mattered little what 

 this explanation turned out to be like in detail if only man rid himself of 

 the superstition which always accompanies a belief in supernatural powers. 

 Epicurus' system, in fact, was expressly based on the idea of creating by the 

 aid of philosophy a pleasant existence, and man attained this best by being 

 an opportunist in all the main problems of life. That on account of this he 

 gained numerous followers is generally acknowledged, but also the principle 

 of a cosmic conception which lays most stress on the exclusion of all super- 

 natural elements, and in doing so does not bother much about the difficulties 

 arising out of questions of detail, has always had, and will indeed always 

 have, keen adherents. It is no matter for surprise, however, that the follow- 

 ers of Epicurus, with such a view of the functions of scientific research, could 

 never claim any really great natural philosopher of antiquity amongst their 

 number. Epicureanism survived as a mode of living which invited people 

 during depressing and hopeless times to seek life's happiness and goal in 

 pleasure, spiritual as well as material. To Epicurus himself and to his friends 

 pleasure was essentially spiritual; their material needs were extremely 

 modest. But matters became worse when his doctrine was brought to Rome. 

 In that world-capital it degenerated into an unbridled worship of pleasure, 

 particularly under the Empire; the fact that Nero and his friends called 

 themselves Epicureans was not calculated to heighten the school's reputa- 



