152 THE THEOKY OF EVOLUTION 



Since, now, each similarity which consists in the 

 possession of one and the same perfection, although 

 in different degrees, must be explained by a common 

 descent, therefore man, animals, and plants have arisen 

 from each other or from common ancestors. 1 



(ii) Criticism. (a) The main argument of the neo- 

 Lamarckians is the assumption a priori that similarity, 

 quite generally and without any limitation, depends 

 on descent. That, however, is false, and, in the sense 

 which is imputed to this assumption by the psycho- 

 biological school, utterly impossible. 



Proof. We have already shown thoroughly that 



1 It has not been easy for us to frame an argument in forma from the 

 programme writings of France, Pauly, and Wagner. Often we stand 

 simply helpless before such expressions as the following, in which France 

 endeavours to make us ' comprehend ' the existence of the plant soul 

 (see Wagner, Gesch. d. Lamarckismus, p. 202) : ' The psychic working 

 principle in plants has so far repeatedly shown itself to be of very re- 

 stricted powers. It will be well always to emphasize this point, since 

 it is precisely thereby that the objection regarding the unjustified human- 

 izing (Vermenschlichuung) of plant actions is in advance struck upon the 

 head.' Nevertheless he proceeds : ' that they [actions of men and plants] 

 are alike in principle, which permits the conclusion that they are of like 

 origin. Therefore the chief characteristic of the plant and cell souls 

 is the narrowness of their judgments,' or in other words, ' the many failures 

 and the manifold stupidities which are found in plant life.' * Plants can 

 be easily deceived, and movements may be caused the futility of which 

 is easily seen by our thought but not by that of the plant.'' Our brain 

 cells see through the stupidity of our body cells because their powers of 

 judgment stand higher. . . . They have learned to do so because from 

 the beginning they have never done anything else than to practise them- 

 selves in judging and thinking, while those (the body cells), as the common 

 working horde, also had to devote themselves to varied handiwork. This 

 affords us the particular key to the spiritual constitution of the plant. [?] 

 The poor thing can only think with body cells ; it has no special thinking 

 organ and has therefore been sent to the bottom of the class in the school 

 of life.' 



