INTKODUCTION. 



A VAEIETT OP CONSIDERATIONS seems to me to render it de- 

 sirable that I should explain shortly the circumstances under 

 which, the following work has been written. On the one hand, 

 for instance, the value of an author's opinion on a given 

 subject necessarily depends on his qualifications for forming 

 and expressing an opinion ; which qualifications include the 

 natural bias of his mind, the direction in which his mental 

 qualities have been cultivated, the nature and extent of his 

 opportunities for observation, with the degree to which he has 

 availed himself of his opportunities, the extent and variety 

 of his teaching in other words, his special experience and 

 aptitude -in the investigation of the said subject. 



On the other hand, the subject of Mind in the Lower 

 Animals is one that has from time immemorial been re- 

 garded, if not studied, from the most different points of 

 view, and one that will doubtless continue to be so regarded. 

 Theologians, metaphysicians, psychologists, physiologists, 

 naturalists, physicians, veterinarians, philosophers so called 

 of the most diverse views and feelings, naturally and neces- 

 sarily approach such a subject actuated by the most conflict- 

 ing motives and opinions, by prejudice the most unreason- 

 able, by ignorance the most profound. 



Now, I have studied the subject of mind in other ani- 

 mals as compared with that of man, for a series of years, 

 simply as a physician-naturalist. 



As a physician it has been the special business of my 

 professional life to deal practically with the phenomena of 

 abnormal mentalisation in man a circumstance that has 



