58 HERBERT ALBERT RATNER 



mean for example that astronomical experience supplies the 

 principles of astronomical science: for once the phenomena 

 were adequately apprehended, the demonstrations of astron- 

 omy were discovered. Similarly with any other art or science. 

 Consequently, if the attributes of the things are apprehended, 

 our business will then be to exhibit readily the demonstrations."^® 



Again Aristotle emphasizes that " each set of principles we 

 must try to investigate in the natural way, and we must take 

 pains to state them definitely, since they have a great influ- 

 ence on what follows. For the beginning is thought to be more 

 than half of the whole, and many of the questions we ask are 

 cleared up by it." ^'^ 



Harvey, of course, as an Aristotelian, does not limit himself 

 to man. To get at the heart of the matter and of man he must 

 be interested in the hearts of other animals. His aim is to get 

 at the true nature of the heart. His interest is not descriptive. 

 He is not interested in this heart or that with the variations in 

 numbers of chambers or differing associations with lung or gills, 

 but in the heart universally considered, prescinding from the 

 variations that are found in nature. He refers to cold blooded 

 animals as well as to warm blooded: toads, snakes, frogs, snails, 

 shellfish and fish. In all it has been estimated that he worked 

 with about 80 species of animals .^^ 



That this is a methodological approach and not simply the 

 insatiable curiosity of a field biologist is made clear from the 

 quote from Aristotle that appears on the title page of Prelec- 

 tiones, from the fifth of the canons which Harvey lists for 

 his own guidance at the beginning of his lectures, and from a 

 passage from Harvey that appears in De Motu. 



The Aristotle quotation states, " The fact is that the inner 

 parts of man are to a very great extent uncertain and unknown, 

 and the consequence is that we must have recourse to a con- 



''^ Prior Analytics, Bk. 1, ch. 30, 46 a 18-27. 

 ^^ Nico-machean Ethics, Bk. 1, ch. 7, 1098 b 4-9. 



'^ William Harvey, Prelectiones, ed. cit.. Introduction by a Committee of the 

 Royal College of Physicians of London, p. vi. 



