INTRODUCTION. 11 



I should like to have it also understood that it is further 

 restricted to the psychology as distinguished from the philo- 

 sophy of the subject. In a short and independent essay, 

 published elsewhere,* I have already stated my views con- 

 cerning the more important questions of philosophy into 

 which the subject-matter of psychology is so apt to dip ; but 

 here it is only needful to emphasize the fact that these two 

 strata of thought, although assuredly in juxtaposition, are 

 no less assuredly distinct. My present enquiry belongs only 

 to the upper stratum, or to the science of psychology as dis- 

 tinguished from any theory of knowledge. I am in no wise 

 concerned with " the transition from the object known to the 

 knowing subject," and therefore I am in no wise concerned 

 with any of the philosopliical theories which have been pro- 

 pounded upon this matter. In other words, I have every- 

 where to regard mind as an object and mental modifications as 

 phenomena ; therefore I have throughout to investigate the 

 process of Mental Evolution by what is now generally and 

 aptly termed the historical method. I cannot too strongly 

 impress upon the memory of those who from previous reading 

 are able to appreciate the importance of the distinction, that 

 I thus intend everywhere to remain within the borders of 

 psychology, and nowhere to trespass upon the grounds of 

 philosophy. 



On entering so wide a field of enquiry as that whose limits 

 I have now indicated, it is indispensable to the continuity of 

 advance that we should be prepared, where needful, to supple- 

 ment observation with hypothesis. It therefore seems desira- 

 ble to conclude this Introduction with a few words both to 

 explain and to justify the method which in this matter I 

 intend to follow. 



It has already been stated that the sole object of this 

 work is that of tracing, in as scientific a manner as possible, 

 the probable history of Mental Evolution, and therefore, of 



* Nineteenth Century, December, 1882. 



