THE DEVELOPMENT OF THE SCIENTIFIC METHOD 73 



is Lucretius, whose book, On the Nature of Things, is often 

 regarded as a predecessor of our inodern ideas, especially as 

 Lucretius, follo^ving the Epicurean philosophy, explains the 

 origin of the entire Avorld as due to the interaction of atoms, 

 so that atoms are the only reality. The best-known writer on 

 scientific subjects during the Roman period was the elder 

 Pliny, who ^vrote a natural history consisting of a vast collec- 

 tion of observations and statements about animals and plants, 

 many of them hearsay. Pliny's book formed a kind of en- 

 cyclopedia that ^vas accepted as the best description of the 

 natural world for a thousand years; and, although un- 

 doubtedly it represented progress at the time, its authority 

 was eventually detrimental to the improvement of natural 

 kno^vledge. 



More and more, the Greek inspiration, which so nearly 

 achieved the discovery of the experimental method of science, 

 died out, and, except for the occasional appearance of indi- 

 vidual thinkers, the world steadily receded into intellectual 

 darkness. Among these individual thinkers, one of the great- 

 est was Galen of Pergamum, who ranks with Hippocrates as 

 the outstanding medical authority of the ancients. Galen 

 made accurate anatomical and physiological studies of many 

 animals and worked out a complete physiological system that 

 survived as the accepted description of physiology until the 

 sixteenth century. As Singer says, "The ^vhole knowledge 

 possessed by the world in the department of physiology— 

 nearly all the biological conceptions, most of the anatomy, 

 much of the botany, and all the ideas of the physical structure 

 of living things from the third to the sixteenth century— were 

 contained in a small number of works of Galen." * The 

 works were translated into many languages, commented on 

 by later writers, and reproduced in many forins. Galen be- 

 lieved that everything was made by God to a particular end, 

 .a doctrine known as teleology. Because this view fitted the 

 theological attitude of the Middle Ages so perfectly, Galen 

 became the authority in his field. 



* Charles Singer, op. cit., p. 92. 



