52 HERBERT ALBERT RATNER 



Gen. and Cor., Bk. II, Ch. 11, Meteorology, Bk. II, Ch. 4, 

 among others. Aristotle divides natural locomotion into circu- 

 lar and rectilinear. Only circular motion can be single and 

 continuous. When Harvey concludes in Ch. 14 that " it is 

 absolutely necessary to conclude that the blood in the animal 

 body is impelled in a circle, and is in a state of ceaseless 

 (perpetuo) motion . . ." he is talking in a strict Aristotelian 

 framework. 



Harvey, in the development of this conclusion, had to combat 

 in his own mind the prevailing physiological concept that 

 blood was produced from nutriment in a central organ, and 

 was moved peripherally to be totally consumed by the body. 

 That Harvey refers to Aristotle's concept of circular motion in 

 his exposition, which is in the order of demonstration, suggests 

 the critical role that Aristotle's concept had in the order of 

 discovery. 



THE DEMONSTRATION OF THE MOTION OF THE HEART 



AND BLOOD 



Harvey makes it clear throughout his work that his " new 

 views of the motion and use of the heart and the circulation of 

 the blood " "^ are the result of the application of both sense 

 and reason. In his dedication to the learned physicians he 

 states that " for nine years or more [he has] confirmed these 

 views by ocular demonstrations [and] manifested them by 

 reasons and arguments, freed from the objections of the most 

 learned and skillful anatomists." In Ch. 14 entitled ' The 

 Conclusion of the Demonstration of the Circulation of the 

 Blood ' where he concludes that the blood is impelled to the 

 whole body by the pulse of the ventricles, he states that this is 

 " confirmed by reason and ocular experiment," and that one 

 must " necessarily conclude " that the motion of the blood is 

 circular. In the final words of the concluding chapter of his 

 book, the chapter which confirms the motion and the circula- 

 tion of the blood through an anatomical analysis of the heart, 



'^ Harvey, Works, ed. cit., Dedication to Learned Physicians, p. 5. 



