226 UNIVERSITY OF COLORADO STUDIES 



less simple sensation. All sensibility is connected with material changes 

 in the protoplasm. ' In the lowest animals and in plants the psychoplasm, 

 the indispensable substratum of any psychic activity, has not reached an 

 independent differentiation. He then gives five chief stages of sensibility 

 from the point at which the whole psychoplasm is sensitive to the point at 

 which ^'conscious perception is developed by the mirroring of the sensa- 

 tions in a central part of the nervous system, as we find in man and the 

 higher vertebrates, and probably in some of the higher invertebrates, 

 notably the articulata," 



Both writers, then, hold that the origin of simple sensation and 

 consciousness is connected with the arrangement of the ultimate 

 particles of substance. Lucretius maintains that sensibility may 

 arise from insensible atoms; whereas Haeckel attributes to his atoms 

 the simplest form of sensation. Both, of course, deny any divine 

 interposition at the point where it is so often demanded, the origin 

 of consciousness.^ 

 7. Rational Thought and the Origin of the Cognate Faculty, Speech 



Recalling our treatment of the preceding topic and of the immor- 

 tality of the soul, it is hardly necessary to state that for both Haeckel 

 and Lucretius rational thought is simply the culmination of our 

 psychic gradations. 



As to the origin of language Haeckel^ is contented to point out that 

 "here also we have to recognize a long chain of evolution which stretches 

 unbroken from the lowest to the highest stages. Speech is no more 

 an exclusive prerogative of man than reason. In the wider sense it is a 

 common feature of all the higher gregarious animals, at least of all the 

 articulata and the vertebrates, which live in communities or herds. This 

 is effected either by touch or by signs, or by sounds having a definite 

 meaning. The song of the bird or of the anthropoid ape (Hylobates), the 

 barking of the dog, the neigh of the horse, the chirp of the cricket, the cry 

 of the cicada, are all specimens of animal speech. Only in man, how- 

 ever, has that articulate conceptual speech developed which has enabled 



' WR., 108 seq. 



= Their views as to consdousness ia its higher forms have been compared in Part I of the paper in the 

 preceding number of the Studies. 

 3 WR., 126. 



