LAMARCK'S ZOOLOGICAL AXIOMS 219 



can have in itself the power of moving, living, feeling, 

 thinking, nor of having ideas ; and if, outside of man, 

 we observe bodies endowed with all or one of these faculties, 

 we ought to consider these faculties as physical phenomena 

 which Nature has been able to produce, not by employing 

 some particular kind of matter which itself possesses one or 

 other of these faculties, but by the order and state of things 

 which she has constituted in each organisation and in each 

 particular system of organs. 



"2. Every animal faculty, of whatever nature it maybe, 

 is an organic phenomenon, and results from a system of 

 organs or an organ-apparatus which gives rise to it and upon 

 which it is necessarily dependent. 



" 3. The more highly a faculty is developed the more 

 complex is the system of organs which produces it, and 

 the higher the general organisation ; the more difficult also 

 does it become to grasp its mechanism. But the faculty 

 is none the less a phenomenon of organisation, and for that 

 reason purely physical" (p. 104). 



According to these " axioms " function is a direct and 

 mechanical effect of structure. 



The curious thing is that in spite of his avowed material- 

 ism, Lamarck's conception of life and evolution is profoundly 

 psychological, and from the conflict of his materialism and 

 his vitalism (of which he was himself hardly conscious), arise 

 most of the obscurities and the irreductible self-contradiction 

 of his theory. 



Lamarck divided animals (psychologically !) into three 

 great groups apathetic or insensitive animals, animals 

 endowed with sensation, and intelligent animals. The first 

 group, which comprise all the lower Invertebrates, are 

 distinguished from other animals by the fact that their 

 actions are directly and mechanically due to the excitations 

 of the environment ; they have no principle of reaction 

 to external influences, but passively prolong into action the 

 excitations they receive from without. They are irritable 

 merely. The second group are distinguished from the 

 first by their possessing, in addition to irritability, a power 

 which Lamarck calls the sentiment interienr. He has some 

 difficulty in defining exactly what he means by it: "I 



