Introduction xxvii 



most recent account of this from his " Development and 

 Evolution " (1902) : — '^ 



" The general fact is that the organism reacts by concen- 

 tration upon the locality stimulated for the continuance of 

 the conditions, movements, stimulations, which are vitally 

 beneficial, and for the cessation of the conditions, movements, 

 stimulations which are vitally depressing." 



Tills amounts to saying in the terminology of Jenning 

 (see below) that the living organism alters its " physio- 

 logical states " either for its direct benefit, or for its in- 

 direct benefit in the reduction of harmful conditions. 



Again : — 



" This form of concentration of energy on stimulated locali- 

 ties, with the resulting renewal through movement of con- 

 ditions that are pleasure-giving and beneficial, and the 

 consequent repetition of the movements is called ' circular 

 reaction.' " 



Of course, the inhibition of such movements as would 

 be painful on repetition is merely the negative case of the 

 circular reaction. We must not put too much of our own 

 ideas into the author's mind ; he nowhere says explicitly 

 that the animal or plant shows its sense and does this 

 because it likes the one thing and wants it repeated, or 

 dislikes the other and stops its repetition, as Butler would 

 have said. Baldwin is very strong in insisting that no 

 full explanation can be given of living processes, any more 

 than of history, on purely chemico-physical grounds. 



The same view is put differently and independently by 

 H, S. Jennings,^ who started his investigations of living 



' He says in a note, " This general type of reaction was de- 

 scribed and illustrated in a different connection by Pfluger in 

 ' Pfluger's Archiv. f.d. ges. Physiologie,' Bd. XV." The essay 

 bears the significant title " Die teleologische Mechanik der lebendigen 

 Natur," and is a very remarkable one, as coming from an official 

 physiologist in 1877, when the chemico-physical school was nearly 

 at its zenith. 



'^ "Contributions to the Study of the Lower Animals" (1904), 

 " Modifiability in Behaviour " and " Method of Regulability in 

 Behaviour and in other Fields," in Journ. Experimental Zoology, 

 vol. ii. (1905). 



