MENTAL PHYSIOLOGY. 



715 



opinion that consciousness resides in the cerebral convolutions, and 

 that we are conscious of all mental changes which take place therein. 

 It is somewhat remarkable that, notwithstanding the large part 

 which consciousness, or want of consciousness, plays in Dr. Carpen- 

 ter's system, he has nowhere attempted to show wherein it consists or 

 of what it is composed. Certainly it is in great part composed of the 

 perception of sensations coming from without, and, so far, may well 

 be located in the sensorium commune. The ccBncesthesis also, the 

 common feeling of the organism, enters largely into its composition, 

 and may have its place of recognition in the same cerebral centre. 

 But evidence has yet to be sought that the consciousness of ideas, 

 whether they be intellectual or emotional, has its seat elsewhere than 

 in that part of the brain where these ideas are formed, namely, in the 

 cortical layer of the cerebral convolutions. Dr. Carpenter appears to 

 adopt the metaphysical opinion that consciousness is the perception 

 of the ego, and as such is one, simple and indivisible, but the physio- 

 logical view of consciousness will be that it is highly complex, and 

 comj)ounded variously at every varying moment of perception, ideas, 

 and emotions, some of which obtrude more or less upon the attention, 

 some of which are more or less faint and unrecognized, but which 

 nevertheless exist, and can be found, if the attention be directed to 

 them. The consciousness always is, and must be, highly complex. 

 Even when an intense sensation seems to convert the whole body into 

 one great pain, one sense of torture, there is that sense and the idea 

 of it, and the emotion it causes, and some appreciation of the sur- 

 roundings faintly recognized; even in melancholia attonita, when 

 some one frightful delusion has taken possession of the mind to such 

 an extent that the patient seems to have sunk into the abyss of de- 

 mentia, he still hears and sees, and has some apprehension of his sur- 

 roundings, so that even in this case his consciousness is the compound 

 result of very different sensibilities. Some of these are forgotten by 

 the memory, some are lost, but none are forgotten by the mind. As 

 a feather falls not to the earth without drawing the earth to itself, so 

 in psychics, the most feeble and transient sensation, unnoticed and not 

 forgotten, because never really placed in the memory, is still a factor 

 of the mind through all its subsequent existence, and in the history 

 of all mind forever. 



A due appreciation of the elements of consciousness, from this point 

 of view, will perhaps lead Dr. Carpenter to admit that unrecognized 

 and unremembered parts of consciousness have still existed among its 

 components, and that, as no motion of matter can exist for a moment 

 without leaving results in modifications of physical universe, so these 

 unrecognized and unremembered parts of consciousness must serve in 

 the chain of mental paternity or genealogy of all succeeding mental 

 states. 



The chapter on insanity is excellent, barring the intrusion of the 



