WILLIAM HARVEY, M. D. 57 



In subsequent chapterS^ Harvey begins to record his reading 

 of the book of nature. In Chapters 2-5, he reports what she 

 says about the heart and arteries. By obtaining the true attri- 

 butes of these critical components of the cardiovascular system, 

 their motion, pulse and action, he will be in a position subse- 

 quently to elucidate their use and utility. " For if none of the 

 true attributes of things have been omitted in the historical 

 survey " states Harvey's mentor Aristotle, " we should be able 

 to discover the proof and demonstrate everything which ad- 

 mitted of proof, and to make that clear, whose nature does not 

 admit of truth." Aristotle emphasizes in this same passage 

 that " in each science the principles which are peculiar are 

 the most numerous. Consequently it is the business of experi- 

 ence to give the principles which belong to each subject. I 



cause they profess to teach wisdom, and wisdom is nothing else than the knowl- 

 edge of truth . . . Truth is, indeed, divine for it is found fundamentally and 

 primarily in God. That is why Aristotle insists on the sacredness of the duty of 

 holding truth dearer than friends . . . Plato is of the same opinion. For, once, 

 when setting aside a theory of his master, Socrates, he declares that truth must 

 be our supreme concern. And elsewhere, he declares: Socrates is, indeed, a friend 

 of mine, but truth is a greater friend. And in a third text, he declares that one may 

 make little of Socrates, but one must make much of truth." (St. Thomas Aquinas, 

 In I Ethic, lect. 6, nn. 76, 78) . 



^* This is another expression of the true Aristotelian position. " God, like a good 

 teacher, has taken care to compose most excellent writings that we may be in- 

 structed in all perfection. ' All that is written,' says the Apostle, ' is wi'itten for our 

 instruction.' And these writings are in two books: the book of the creation and 

 the book of the Holy Scriptures. In the former are so many creatures, so many 

 excellent writings that deliver the truth without falsehood. Wherefore Aristotle, 

 when asked whence it was that he had his admirable learning, replied: ' From 

 things, which do not know how to lie.' " (St. Thomas, Sermo 5 in Dom. II de 

 adventu, ed. Vives, Opera Omnia, XXIX, p. 194). 



William Harvey, who, on the one hand, makes clear that " the authority of 

 Aristotle has always such weight with me that I never think of differing from 

 him inconsiderately " (Harvey, Anatomical Exercises on the Generation of Animals, 

 Ex. 11, ed. cit., p. 207), also states that " 'Wlioever, therefore, sets himself to 

 opposition to the circulation, because [he] regards it as in some sort criminal to 

 call in question disciplines that have descended through a long succession of 

 ages, and carry the authority of the ancients; to all these I reply: that the facts 

 manifest by the senses wait upon no opinions, and that the works of nature bow to 

 no antiquity; for indeed there is nothing either more ancient or of higher authority 

 than nature." (Second Exercise to John Riolan, ed. cit., p. 123) . 



