Editor's Introduction xix 



" I hold to be unworthy of a philosopher and a searcher 

 after truth. I believe I shall do better and more 

 advisedly if I meet so many indications of ill breeding 

 with the light of faithful and conclusive observation." 1 

 To many of the attacks made on his discovery or on 

 himself, he therefore did not condescend to reply. And 

 when from the eminence of his opponents he felt called 

 upon to do so, he replied with the utmost courtesy and 

 kindliness. But whilst admitting the high claims to 

 distinction on other grounds of his antagonist, he pro- 

 ceeded on this particular question to utterly demolish 

 him with clear facts and stern irrefutable arguments 

 and experiments. He called upon his opponents to 

 observe the facts and make the experiments for them- 

 selves, instead of citing the opinions of authors centuries 

 old, or making long discourses on spirits, fuliginous 

 vapours, and the tides of Euripus. This is well illus- 

 trated in his replies to Riolan. The arguments of 

 Riolan would hardly seem to have entitled him to the 

 honour of the special notice of the great discoverer. 

 But probably his position as Anatomist in the University 

 of Paris, and of physician to the Queen-Mother, Marie 

 de Medicis, made Harvey pick out his criticisms as a 

 suitable excuse for replying to his opponents. Harvey's 

 mode of argument is well shown by the following 

 admirable remarks on the Manner and Order of Acquir- 

 ing Knowledge, in his introduction to the work on 

 "The Generation of Animals " : "Sensible things are of 

 themselves and antecedent ; things of intellect however 

 are consequential and arise from the former, and indeed 

 we can in no way attain to them without the help of 

 the others. And hence it is that without the due 

 admonition of the senses, without frequent observation 

 and reiterated experiment, our mind goes astray after 

 phantoms and appearances. Diligent observation is 

 therefore requisite in every science, and the senses are 

 to be frequently appealed to. We are, I say, to strive 



1 Vide Second Reply to Riolan, p. 133 post. 



