180 MENTAL CONSTITUTION OF ANIMALS. 



recognized as free will in man, being nothing more than 

 a vicissitude in the supremacy of the faculties over each 

 other. 



It is a common mistake to suppose that the individuals 

 of our own species are all of them formed with similar 

 faculties — similar in power and tendency — and that edu- 

 cation and the influence of circumstances produce all 

 the differences which we observe. There is not, in the 

 old systems of mental philosophy, any doctrine more op- 

 posite to the truth than this. It is refuted at once by the 

 great differences of intellectual tendency and moral dis- 

 position to be observed among a group of young children 

 who have been all brought up in circumstances perfectly 

 identical — even in twins, who have never been but in one 

 place, under the charge of one nurse, attended to alike 

 in all respects. The mental characters of individuals are 

 inherently various, as the forms of their persons and the 

 features of their faces are; and education and circum- 

 stances, though their influence is not to be despised, are 

 incapable of entirely altering these characters, where 

 they are strongly developed. That the original charac- 

 ters of mind are dependent on the volume of particular 

 parts of the brain and the general quality of that viscus, 

 is proved by induction from an extensive range of obser- 

 vations, the force of which must have been long since 

 universally acknowledged but for the unpreparedness of 

 mankind to admit a functional connexion between mind 

 and body. The different mental characters of individu- 

 als may be presumed from analogy to depend on the same 

 law of development which we have seen determining 

 forms of being and the mental characters of particular 

 species. This we may conceive as carrying forward the 

 intellectual powers and moral dispositions of some to a 

 high pitch, repressing those of others at a moderate 

 amount, and thus producing all the varieties which we 

 see in our fellow-creatures. Thus a Cuvier and a New- 

 ton are but expansions of a clown, and the person em- 

 phatically called the wicked man is one whose highest 

 moral feelings are rudimental. Such differences are not 

 confined to our species ; they are only less strongly marked 

 in many of the inferior animals. There are clever dogs 

 and wicked horses, as well as clever men and wicked men, 

 and education sharpens the talents, and in some degree 

 regulates the dispositions of animals, as it does our own 



