8 DEVELOPMENT AND PURPOSE CHAP. 



supposed to be complete. Upon this process the mental 

 or conscious series is at a certain point superimposed, and 

 at another point taken off again. It is as it were a tem- 

 porary, and so far as the effect of the process is concerned, 

 an accidental and superfluous addition. It is clear from 

 the supposition that the mechanical order must determine 

 itself, and the conscious order take a secondary place. 

 Consciousness in fact becomes what some writers have 

 called it, an Epiphenomenon. So far as the course of 

 events in the universe is concerned, consciousness, feeling^ 

 intelligence, forethought, resolution, might as well not be. 

 The secret of organic life is the intricate adaptation of 

 physical structure to respond in such manner as the life 

 requirements of the species dictate to the circumstances of 

 the physical environment. 



I shall not for the moment attempt to resolve the diffi- 

 culties briefly set out. Whether a solution securing a 

 more real position to the conscious factor is ultimately 

 possible will be found to turn in the end on the question 

 whether every event or phase of process must be supposed 

 to proceed uniformly from a pre-existing phase or whether 

 it may be conceived (as we seem to conceive our own 

 efforts) as really determined by relation to that which it 

 itself brings about. With this question we shall deal at 

 length in its turn, and from the discussion some light may 

 I hope be obtained. We may note for the present that the 

 psycho-physical view which reduces the whole mind-life to 

 the rank of an epiphenomenon is merely the most extreme 

 and consistent expression of a result to which the biological 

 treatment of mental evolution tends. c Mind ' is here in 

 all essentials evolved structure. Biologists may be careful 

 to eschew metaphysics and may avoid the charge of 

 materialism by a judicious selection of phrases. None the 

 less it lies in the nature of the biological treatment to think 

 of mental activity like all activity, like muscular contrac- 

 tion or glandular secretion, like respiration or digestion, 

 as the function of a structure. That structure is the 

 cerebro-spinal nervous system, and the functions which 

 that system performs may be summed up in one formula. 

 They are such as to accommodate the actions of the organ- 



