INTELLECTUAL AND MORAL FACULTIES. 131 



see, the ears hear, the tongue tastes, the nose smells, the 

 stomach digests food, the heart circulates the blood, the liver 

 secretes bile, &c. Even where the function is compound, 

 as in the tongue, where a feeling, taste, and motion are all 

 combined, we find a separate nerve for each function, and 

 the same occurs in every part of the body. Now, as no 

 nerve performs two functions, we may, reasoning from 

 analogy, conclude, that it is so in the brain ; different sen- 

 timents, different faculties, and different propensities, require 

 for their manifestation different organs or portions of cerebral 

 matter./ 



24. Again, the external senses have for their exercise, not 

 only separate and external organs, but also as many separate 

 internal organs. Hearing, seeing, smelling, &c., require 

 different portions of cerebral substance for their exercise ; 

 may we not then from analogy, be justified in the conclusion, 



/that there are as many cerebral, or nervous systems, or 

 organs, as there are special internal senses, and particular 

 intellectual and moral faculties ?) ^The legitimate inference 

 then is, that each faculty does possess in the brain a nervous 

 organ appropriated to its production, the same as each of the 

 senses has its particular nervous organ.i 



25. The structure of the brain is not homogeneous, but 

 differs greatly in different parts, both in composition, form, 

 colour, consistence, and arrangement. But what object 

 could there be in all this variety, if the brain acted as a 

 whole, and there was but a single intellectual principle or 

 faculty ? A difference of structure shows that there must be 

 a difference of function, and as the brain has been proved to 

 be the organ of the mind, it follows that different portions or 

 organs of the brain must be employed by the intellectual and 

 moral faculties. 



26. The faculties do not all appear at once, nor do they fail 

 at once, but they appear in succession, and as a general rule, 

 the reflecting or reasoning faculties are the latest in arriving 

 at perfection. So also the organization of the brain is un- 



