258 THE HUMAN SPECIES 



inner existence of that unity whose external manifestations we 

 are wont to regard as life. The psychic functions, like the 

 bodily, are allotted to certain central regions, and every external 

 process corresponds with a change in the internal conditions. 

 A self-consciousness of this inner state first becomes possible 

 when the alliance founded upon the external and internal organ- 

 ism includes the conditions necessary for the constant renewal of 

 the processes, and for associating the present state with the past 

 Therefore the existence of a consciousness in the lower forms 

 of life is excluded. In a slightly higher grade of animals the 

 consciousness is in a rudimentary stage, in man it is perfect, 

 having reached to a point where he can conceive of a world 

 outside the material self. In his later years Wundt's l views 

 underwent a striking change. He deserted monism and advo- 

 cated the old dualism in a new garb. 



" Psychical can only be adequately explained from psychical, 

 just as motion can only be derived from motion, and never from 

 a mental process, of whatever kind." - 



" The connection can only be regarded as a parallelism of 

 two causal series existing side by side, but never directly inter- 

 fering with each other in virtue of the incomparability of their 

 terms." 3 



" Psycho-physical parallelism is a principle whose applica- 

 tion extends only to the elementary mental processes, to which 

 definite movement processes run parallel, not to the more com- 

 plicated products of our mental life." 4 



" Our mind is nothing else than the sum of our inner ex- 

 periences, than our ideation, feeling and willing, collected 

 together to a unity in consciousness and rising in a series of 

 developmental stages to culminate in self-conscious thought and 

 a will that is morally free." 5 



Haeckel has energetically opposed this relapse of Wundt's to 

 the old dualism from the standpoint of the scientific conception 

 which regards psychology merely as a branch of physiology,, 

 and the mind as having no immaterial supernatural existence 

 but as a natural phenomenon, the sum of the phenomena of life 



1 Vorlesungen liber Menschen- und Tierseele, 1892, p. 480. 

 2 Wundt, Human and Animal Psychology, London, 1896, p. 442. 

 3 Ibid., p. 442. 4 Ibid., p. 447. '' Ibid., p. 451. 



