240 NOTES ON THE NATURE OF INSANITY. 



can savage : it is a distinction that can never be obliterated. Re- 

 lying on the impregnability of this induction, we may inquire — 

 What, then, do we observe, in the formation of man, uniformly 

 distinct from that which exists in all other animals ? His brain has 

 a more exquisite organization, and a great multiplication of its 

 parts, many of which are not found in any other animals, even the 

 most perfect ; although, with this exception, there is no other part 

 of the human body which, in one or other of them, is not more or 

 less developed. Now, since there appears to be a certain limit to 

 the manifestations of mental power in each class of animals, so also 

 it is exceedingly probable that there exists a great difference in the 

 mental capabilities of the individuals whereof each class is com- 

 posed. This much, however, is well known — that, in various 

 quadrupeds and the higher class of animals, and in man more par- 

 ticularly even to a great degree, such a difference actually prevails 

 and is readily distinguishable. 



When we judge whether the functions are healthily performed 

 in any species of animals, we naturally look at the habits and capa- 

 bilities whereby, as a species, it is characterized. We do not then 

 consider the absence of that which is not usually found in such a 

 species, as an indication of disordered function : nor should we rec- 

 kon the existence of a capability much superior to that which 

 appears in other species, as being of itself an evidence of functional 

 soundness, because of the difference of their natural instinctive 

 powers and habits. Is not, then, the same rule applicable to diffe- 

 rent individuals of the same species, and particularly to man? 

 From experience, we learn that an immense difference, both in 

 physical and mental powers and habits, from whatever causes, exists 

 among mankind. Now although it has been fancied that this 

 might be obviated by previous education, yet undoubtedly there are 

 many such differences which no external circumstances could re- 

 move. We should be unable to form an opinion of the soundness 

 of a limb merely from knowing its absolute power : the arm of a 

 strong man, though in a state of disease, may be able to lift a much 

 greater weight than the perfectly healthy arm of a person who is 

 weak and delicate : before the absolute power then can be tested, 

 we must know the previous capabilities. Hence, obviously, it ought 

 to be the first object of our inquiries, in estimating the sanity of 

 an individual, carefully to ascertain what have been the former 

 habits and powers of his mind ; what the state of his feelings and 

 sentiments ; and what his general conduct. Would it not be irra- 

 tional to conclude that a man, possessing great lalents, is necessarily 



