CONSCIOUSNESS. 191 



development. Still, however certain we are of the 

 fact of this natural evolution of consciousness, we 

 are, unfortunately, not yet in a position to enter 

 more deeply into the question and construct special 

 hypotheses in elucidation of it. Palaeontology, it is 

 true, gives us a few facts which are not without 

 significance. For instance, the quantitative and 

 qualitative development of the brain of the placental 

 mammals during the Tertiary period is very remark- 

 able. The cavity of many of the fossil skulls of the 

 period has been carefully examined, and has given us 

 a good deal of reliable information as to the size, and, 

 to some extent, as to the structure, of the brain they 

 enclosed. We find, within the limits of one and the 

 same group (the ungulates, the rodents, or the 

 primates), a marked advance in the later miocene 

 and pliocene specimens as compared with the earlier 

 eocene and oligocene representatives of the same 

 stem : in the former the brain (in proportion to the 

 size of the organism) is 6-8 times as large as in the 

 latter. 



Moreover, that highest stage of consciousness, which 

 is reached by man alone, has been evolved step by 

 step — even by the very progress of civilisation — from 

 a lower condition, as we find illustrated to-day in the 

 case of uncivilised races. That is easily proved by 

 a comparison of their languages, which is closely 

 connected with the comparison of their ideas. The 

 higher the conceptual faculty advances in thoughtful 

 civilised man, the more qualified he is to detect 

 common features amid a multitude of details, and 

 embody them in general concepts, and so much the 

 clearer and deeper does his consciousness become. 



