244 Science Religion and Reality 



several well-known principles in the physics and chemistry of the 

 present day. An obvious illustration is the gyroscope, which when 

 revolving resists strongly any force tending to overturn it, and the 

 facts of buffer action in acid-base systems and poising action in 

 oxidation-reduction systems are obviously of enormous bearing 

 on the point. But to go no further, the principle of Le Chatelier 

 in thermodynamics states that " When a factor determining the 

 equilibrium of a system is altered, the system tends to change so as 

 to oppose and partially annul the alteration in the factor." Surely 

 the tendency of organisms to keep their environments constant is 

 a special case of this thermodynamic principle. As Bayliss says, 

 " The fact that an organism has developed means of returning to 

 the conditions to which it has been previously adjusted may be 

 called ' nostalgia,' but I am unable to see that this makes it essentially 

 different from a physico-chemical system." 



But the most philosophical form of the argument from actual 

 wholeness is the one which maintains that to look at an animal as 

 a physico-chemical system is to abstract unduly from reality, since 

 to do so is to ignore the fact that it is a psycho-physical whole. 

 This criticism, when carried far enough, ends in denying all 

 validity whatever to the scientific method, but Haldane takes care 

 to alight at the proper moment. It is certainly undeniable that 

 science abstracts, generalises, analyses, and constructs a picture of 

 reality probably quite unlike that reality itself. In another of the 

 essays in this book it has been clearly shown that theoretical physics 

 is just such a system — its relations with reality are through the 

 human mind, it is a subjective production. But to use this 

 argument as a chastisement for mechanistic biology is inadmissible. 

 It is not sufficient to meditate upon a typewriter if one desires to 

 understand its mechanism ; like a boy with a new watch, one must 

 pry into it and take it to pieces if one really wants to know how it 

 works. That is the method of natural science. It is perfectly 

 true that it analyses and constructs a partial picture of reality, but 

 the process is essential if an intellectual understanding of the sub- 

 strate is required. Haldane's method is that of the mystic ; not a 

 useless method, but not a scientific method. The attitude of the 

 mystic to the typewriter is to sit down in front of it, until, by a 

 process which psychology cannot define, he feels himself into the 

 typewriter and becomes one with it as a part of the universe. But 

 the scientific method is to take it to pieces, to become familiarly 



