66 THE SCIENCE OF LOGIC 



also of the final causes, of such combination. That is to say, it shows the 

 realization or formation of the compound as the internal reason why the 

 bodies in question combine in that way ; it reveals the finis operis, the intrinsic 

 aim of that activity which is the product and complement of their respective 

 natures or formal causes. 



In some cases, the final cause is even the primary object of inductive re 

 search. This occurs very commonly in physiological investigations into the 

 functions of living organs as, for example, in the efforts of physiologists to 

 discover the functions of the thyroid gland, or of the vermiform appendix. 



217. &quot;PURPOSE&quot; OR &quot;DESIGN&quot; : &quot; FINAL CAUSES&quot; AND 



&quot;LAW&quot; IN PHYSICAL NATURE. It is intelligible that when 

 inquiring into the causes and reasons of phenomena that may be 

 due to human activity we should seek for their final causes, i.e. the 

 motive, the design, the end in view in their production ; but 

 the meaning of seeking for final causes in the natural agencies 

 even of the inorganic world may not be at first apparent : for, 

 how can an agent devoid of perception and appetite, nay, even of 

 life, act &quot;for an end&quot;? Such agents cannot, of course, act &quot;for 

 an end &quot; in the same way as men (&quot; electivJ&quot;\ who, by free will, 

 elect or choose the ends for which they act ; or in the same way 

 as animals (&quot; apprehensive r &quot;), which are conscious of the ends 

 towards which their appetites move instinctively ; but the inani- 

 . mate agencies of the physical universe can and do act, each &quot;for 

 an end,&quot; effectively or equivalently (&quot; executive&quot;&quot;\ i.e. in such a way 

 as to make it clear that they are directed or oriented in their 

 action by a ruling intelligence, and for a purpose. That this 

 is so in fact, we are convinced by the manifest order, harmony, 

 regularity of natural phenomena. We know by experience that 

 the causes at work in the whole vast physical universe act each 

 in its own fixed way, uniformly, regularly : whence we conclude 

 that every such agency must have impressed on its very essence, 

 on its inner constitution, by the Creator, a definite &quot; bent &quot; or 

 &quot; tendency &quot; or &quot; inclination &quot; (&quot; appetitus naturalis &quot;) to act along 

 certain definite lines, and so to discharge its appointed function 

 in the universe. This inner principle of uniform action (which is 

 its substantial or specific formal cause] we call the nature of the 

 agent in question : and when it acts in the ordinary, normal way, 

 we speak of its acting &quot; according to its nature&quot; or &quot; according 

 to the law of its nature &quot;. By the nature of a cause or agent we 

 therefore primarily mean the inner directive principle of its activity : 

 its essence regarded as a source or principle of orderly, intelligible 



