364 PHYSIOLOGY CHAP. 



" When we consider the immense development of the different 

 sciences in the present day, it would seem indeed almost impossible 

 for one human intellect to master several such departments of 

 learning. The problem of the development of the human intellect 

 is therefore among the problems which have of late attracted but 

 few students. Genealogical trees have been made showing the 

 morphological development of the most diverse organisms, but 

 we have not so far heard of genealogical trees of human ideas ; yet 

 every idea of which we make use to-day has not only a starting- 

 point in the process of the ontogenetical evolution of the mind 

 of the single individual in order to be elaborated later on, but 

 has also a long philogenetical history, going back frequently to the 

 origin of humanity, sometimes therefore to the animal series. 

 A study of the philogenetical origin of all the essential elements 

 constituting our present psychic life would undoubtedly be a task 

 of great complexity, but would be as valuable as it is complex ; 

 its solution would go far into the ulterior development of the 

 mind of man. We cannot doubt that this problem will attract 

 more and more attention. Viewing its great complexity, it is 

 comprehensible that until now only a few fragments of it have 

 been studied." 



After mentioning the researches into philosophy made by 

 history (Lamprecht), and into comparative theology by history of 

 religion, which are amongst the modern endeavours to solve some 

 part of the problem of the development of human society, he 

 dwells upon the importance for this purpose of the careful study of 

 ontogenetical development, i.e. the psychogenesis of the child, a 

 proof of Haeckel's fundamental biogenetical law, that the develop- 

 ment of the individual is but a recapitulation of the development 

 of the species. 



The following table shows Verworn's attempt at a provisional 

 reconstruction of the great stages traversed by the mind of man 

 from the beginning of civilisation to our own day. 



I. Period of Sensual Impressionism. The psychic life is . 



dominated entirely by the sensations. The affec- Eolithic civilisa- 

 tions and the sensations are subject to sudden I 1- _ (tertiary 

 changes. The representative associations are still i r ,eriod') 

 elementary and are directly related to passing 

 sensations (psychic state of the higher animals). 



II. Period of the Simple Practical Mind. The imagina- 1 Archeolithic and 



tive associations are no longer directly connected I paleolithic civili- 

 with the passing impressions of the senses, are j sation (late terti- 

 already employed for practical deductions. ary and diluvial). 



A. First combination of ideas formed by casual 

 observation for the purpose of practical in-j 



v diluvial). 



