MIND IN EVOLUTION 541 



is evidence of a rill of ianer life growing into a stream, i.e., there 

 is much that we cannot fully describe in purely physiological terms, 

 there is an increasing difficulty in describing what we see without 

 using psychological terms. This proposition can be discussed apart 

 from any theory of the mind-body ' relation '. It must be noted that 

 it is very difficult for Man to get mentally near the lower animals, 

 whose mental stream is probably in greater part pre-intellectual, 

 more conative than cognitive. 



(a) In the evolution of behaviour a starting-point may be found 

 in the restless tentative movements of Unicellular Animalcules, not 

 far removed from internal automatic movements, (b) Gradually 

 there is established a capacity for reacting in a uniform way to 

 frequently recurring stimuli, (c) The next step is the pursuance 

 of a trial and error method, one reaction being given after another, 

 until, it may be, one relieves the stimulation, (d] The main line 

 is represented by such behaviour as an amoeba exhibits when on the 

 hunt, and this is continued into the sensori-motor experimentation 

 and co-ordination of acts exhibited by ganglionless animals like 

 starfishes, (e) The establishment of a nervous system opened up 

 the possibility of another kind of automatisation, that of reflex 

 actions and tropisms. (/) The main line is continued in experi- 

 mental behaviour at a higher level, where there is definite evidence 

 of ' learning ', where the creature utilises its own experience to 

 compass an end which is not necessarily immediate, (g) The im- 

 provement of the brain opened up the possibility of another kind 

 of hereditary organisation that seen in instinctive behaviour. 

 There is a hereditary awareness of the practical significance of cer- 

 tain configurations and an impulsion to an effective routine which is 

 in some measure independent of practice. Instinctive and experi- 

 mental (sometimes intelligent) behaviour are often mingled, some- 

 times the one element predominates, sometimes the other, (h) The 

 main line is continued into intelligent behaviour, implying experi- 

 mentation and perceptual inference. Of this in the individual 

 lifetime there may be habituation. (t) The climax is in Man's 

 rational conduct, implying conceptual inference and rational pur- 

 posefulness. 



The general feature of the whole evolution is that organisation 

 or automatisation is effected at stage after stage, so that the organ- 

 ism is able to push on less embarrassed. The general result seems 

 to be a growing emancipation of mentality growing evidence of a 

 subjective aspect over and above ordinary activities. 



