MECHANISM AND VITALISM 415 



material has not been synthesized in the laboratory. This must 

 be done before the question will be answered to the satisfaction of 

 all parties concerned. 



In the higher organisms other problems equally difficult remain 

 to be solved. What is thought? Is it a secretion from the brain, 

 a physicochemical reaction, or what? Psychology has done much 

 to show us how the brain operates, what regions control certain 

 muscular reactions, where the thought centers are located, but con- 

 cerning the real nature of thought little has as yet been offered. 

 There are people who believe that thought is the only real sub- 

 stance. To them there are two kinds of reality: material and im- 

 material. ''Thoughts are things" which are as real as sodium and 

 chlorine. The physical scientist, dealing with the physical realm, 

 has a tendency to neglect this other world and to reason that be- 

 cause it cannot be touched by his instruments, therefore it does 

 not exist. Whether thought is the only real substance is certainly 

 a disputable matter, but it must be admitted, in all fairness, that 

 even in our work in the laboratory we are never conscious of the 

 external world directly but only through our thoughts of this 

 world. As pointed out by Berkeley, what we are always comparing 

 is not sodium and calcium but our ideas of these two elements. 

 This may sound like quibbling, but to one who is interested in 

 the fundamental nature of the universe in which he finds himself, 

 these are very important distinctions. 



Connected with this question is that of the nature of the ego 

 or of personality. Is this personality the result of particular phys- 

 icochemical reactions or is it something else? Do only organisms 

 have personality or is it an attribute of inanimate nature as well? 

 Has there been an evolution of this personality from the lowest 

 organisms to the highest, or is it something which has come in 

 only with the more complex manifestations of matter? Before 

 definite answers can be given to any or all of these questions, 

 much work remains to be done. The nature of the problem pre- 

 sents almost insurmountable difficulties, only a few of which may 

 be mentioned in this short book. 



Difficulties in the Way of a Solution.— 1. The vital equilibrium 

 problem. The organism is in a state of perpetual change. The 

 substance which makes up any cell, like that which composes a 

 waterfall, is constantly changing while the form remains the same. 

 It thus exhibits what is called a condition of vital equilibrium. 



