ORGAN OF THE MENTAL FACULTIES. 303 



man is a poet ; another a mathematician ; or one is benevolent, another 

 cruel. If these faculties were the exclusive product of the mind, and of 

 course not to be ascribed to diversity of organization, we should have 

 to admit, that each individual has a different immaterial principle, and 

 of course, that there must be as many kinds as there are individuals. 

 Lastly. The faculties vary in the same individual according to circum- 

 stances. They are not the same in the child as in the adult ; in the 

 adult as in one advanced in life ; in health as in disease ; in waking as 

 in sleep. During an attack of fever they become temporarily deranged ; 

 and are permanently so in all the varieties of insanity. 1 These facts 

 are inexplicable under the doctrine, that they are the exclusive product 

 of the mind or immaterial principle. An immaterial or spiritual prin- 

 ciple ought to be immutable ; yet we should have to suppose it capable 

 of alteration ; of growing with the growth of the body, and of becom- 

 ing old with it ; of being awake or asleep ; sound or diseased. All 

 these modifications must be caused by varying organization of the 

 brain in particular. 



We may conclude, then, that the intellectual and moral faculties are 

 not the exclusive product of the mind; that they require the interven- 

 tion of an organ; and, that this organ is the encephalon, or a part of it 

 the cerebrum or brain is announced by many circumstances. In 

 the first place, they are phenomena of sensibility, and hence we should 

 be disposed to refer them to a nervous organ; and, being the most ele- 

 vated phenomena of the kind, to the highest of the nervous organs. In 

 the second place, inward feeling impels us to refer them thither. We 

 not only feel the process there, during meditation ; but the sense of 

 fatigue, which succeeds to hard study, is felt there likewise. The brain, 

 again, must be in a state of integrity, otherwise the faculties are de- 

 ranged; or, for the time, abolished. In fever, it becomes affected directly 

 or indirectly, and the consequence is, perversion of the intellect, in the 

 form of delirium. If the organ be more permanently disordered, as 

 by the pressure of an exostosis or tumour, or by some alteration in its 

 structure or functions less appreciable in its nature insanity, in some 

 form, may be the result. 



In serious accidents to the encephalon, we observe the importance 

 of the cerebrum to the proper exercise of the mental faculties clearly 

 evinced. A man falls from a height, and fractures his skull. The 

 consequence is, depression of a portion of bone, which exerts a degree 

 of compression upon the brain; or extravasation of blood from some of 

 the encephalic vessels attended with simitar results. From the moment 

 of the infliction of the injury, the whole of the mental and moral mani- 

 festations are suspended, and do not return until the compressing cause 

 is removed by the operation of the trephine. M. Richerand cites the case 

 of a female, who had a portion of the brain accidentally exposed, and 

 in whom it was found, that pressing on the brain completely suspended 

 consciousness, which was not restored until the pressure was removed. 

 A similar case occurred to Professor Wistar; and another is related by 



1 Adelon, art. Encephale, Diet, de Medecine, vol. vii. ; and Physiologie de 1'Homme, torn. i. 

 edit. cit. 



