INTRODUCTION xxi 



■with phenomena sui generis, which are not to be found in the 

 domain of physictt-chemical forces. In the same way, hfe 

 having reached a certain degree of complexity, the laws which 

 govern the elementary phenomena of individual life are insufE* 

 cient to explain the complicated phenomena of organised life. 

 Life, having attained to the organised stage, develops phenomena 

 sui generis peculiar to this stage, and which are not to be found 

 in the sphere of unorganised life with which biology alone deals. 

 Social phenomena difEerentiate themselves from other vital 

 phenomena in that the former are of essentially moral nature. 



We must regard thought, reasoning, and all the psychological 

 developments which characterise social life, as so many products 

 of that social life, as derived from the continuous cerebral inter- 

 action between vast numbers of heterogeneous mentalities 

 having arrived at an active consciousness of the differentiation 

 of the world of " ego " and the world of " non-ego." Psychology 

 falls into two sections, according as we consider the individual 

 or the social aspects of thought. We would use the term 

 psychosocial to characterise the nature of the religious beliefs, 

 of the codes of law and jurisprudence, of the philosophical 

 doctrines, of the pohtical theories, and of all other phenomena 

 which have their origin in social life. Certainly, the genesis of 

 the manifestation of thought in the individual may be left to 

 the psychologist ; but we have also — from another standpoint — ■ 

 the right to see in psychological phenomena a resultant of social 

 life ; and, as such, these phenomena may be designated as psycho- 

 social, and included in the domain of the sociologist. Society is a 

 superorganic type sui generis ; and the irreducible element 

 which characterises society, and which difierentiates sociology 

 from psychology and from all the other sciences, is the psycho- 

 social phenomenon. 



Society being thus characterised by an element which differ- 

 entiates the social type from the organic type, we may consider 

 this element as assmning a preponderating role in the measure 



