442 HISTOKY OF PHYSIOLOGY. 



tensions of collections of strings could do, and an exact practical acquain 

 tance with the muscular cordage which exists in the animal frame ; 

 in short, in this as in other instances of real advance in science, there 

 must have been clear ideas and real facts, unity of thought and extent 

 of observation, brought into contact. 



Sect. 2. Recognition of Final Causes in Physiology. Galen, 



THERE is one idea which the researches of the physiologist and the 

 anatomist so constantly force upon him, that he cannot help assuming 

 it as one of the guides of his speculations ; I mean, the idea of a pur- 

 pose, or, as it is called in Aristotelian phrase, a final cause, in the 

 arrangements of the animal frame. It is impossible to doubt that the 

 motive nerves run along the limbs, in order that they may convey to 

 the muscles the impulses of the will ; and that the muscles are attached 

 to the bones, in order that they may movl and support them. This 

 conviction prevails so steadily among anatomists, that even when the 

 use of any part is altogether unknown, it is still taken for granted that 

 it has some use. The developemerit of this conviction, of a purpose 

 in the parts of animals, of a function to which each portion of the 

 organization is subservient, contributed greatly to the progress of 

 physiology ; for it constantly urged men forwards in their researches 

 respecting each organ, till some definite view of its purpose was 

 obtained. The assumption of hypothetical final causes in Physics may 

 have been, as Bacon asserts it to have been, prejudicial to science ; but 

 the assumption of unknown final causes in Physiology, has' given rise 

 to the science. The two branches of speculation, Physics and Physi- 

 ology, were equally led, by every new phenomenon, to ask thdir ques- 

 tion, "Why?" But, in the former case, "why" meant "through 

 what cause ?" in the latter, " for what end ?" And though it may be 

 possible to introduce into physiology the doctrine of efficient causes, 

 such a step can never obliterate the obligations which the science owes 

 to the pervading conception of a purpose contained in all organization. 

 This conception makes its appearance very early. Indeed, without 

 any special study of our structure, the thought, that we are fearfully 

 and wonderfully made, forces itself upon men, with a mysterious im- 

 pressiveness, as a suggestion of our Maker. In this bearing, the 

 thought is developed to a considerable extent in the well-known pas- 

 sage in Xenophon's Conversations of Socrates. Nor did it ever lose its 

 !]<': on sober-minded and instructed men. The Epicureans, indeed, 



