356 BIOLOGICAL SCIENCES AND MEDICINE XIV 



have seen, is a perturbation of the normal activities 

 of a living body, and it is, and must remain, unin- 

 telligible, so long as we are ignorant of the nature 

 of these normal activities. In other words, there 

 could be no real science of pathology until the 

 science of physiology had reached a degree of 

 perfection unattained, and indeed unattainable, 

 until quite recent times. 



So far as medicine is concerned, I am not sure 

 that physiology, such as it was down to the time 

 of Harvey, might as well not have existed. Nay, 

 it is perhaps no exaggeration to say that, within 

 the memory of living men, justly renowned 

 practitioners of medicine and surgery knew less 

 physiology than is now to be learned from the 

 most elementary text-book ; and, beyond a few 

 broad facts, regarded what they did know as of 

 extremely little practical importance. Nor am I 

 disposed to blame them for this conclusion; 

 physiology must be useless, or worse than useless, 

 to pathology, so long as its fundamental concep- 

 tions are erroneous. 



Harvey is often said to be the founder of 

 modern physiology ; and there can be no question 

 that the elucidations of the function of the 

 heart, of the nature of the pulse, and of the course 

 of the blood, put forth in the ever-memorable 

 little essay, " De motu cordis," directly worked a 

 revolution in men's views of the nature and of the 

 concatenation of some of the most important 



