Human Physiology. 779 



of mental derangement. In this life, in its ordinary phases, 

 sensation, thought, memory, and will all mental powers de- 

 pend upon the condition and action of the brain. The larger 

 the brain, other things being equal, the greater the mental 

 power. The finer the quality of the brain, the more delicate 

 its organisation, the finer the quality of thought and feeling. 



As the human mind is composed of a great variety of in- 

 tellectual faculties, sentiments, propensities, it is natural to 

 suppose that the brain is divided into as many distinct organs. 

 There is no indication in the brain itself of such a division ; 

 but this does not prove that it does not exist. We refer our 

 intellectual operations to the forehead ; our higher sentiments 

 to the upper part of the brain, our lower sentiments and pro- 

 pensities to the lower and back portion. If we can make any 

 such division, there is no limit to it, and every distinct faculty 

 must have its organ. If there is a portion of the brain devoted 

 to the perception of form, and another to mathematical cal- 

 culations, another to the perception of tones, etc., and if 

 differences in the strength of these faculties correspond to the 

 development of such portion of the brain, we have the basis of 

 the science of Phrenology. If the brain, as a whole, is engaged 

 in every mental operation, we can see why a man with a large 

 brain should have more mental power than one with a small 

 brain, but we cannot see why men should differ as widely as 

 they do in character and intellect why one should have a 

 talent for music, another for mathematics, a third for painting, 

 or poetry, or engineering. Division of labour, and a distinct 

 organ for every distinct function, seems to be the law of life. 

 But in almost everything we do, many faculties come into play, 

 and there must be a combined action of many organs. There 

 seems, therefore, to be a necessity for some combining and 

 directing power something which shall preside over, control, 

 and direct, all the organs of the mind, as the mind or will con- 

 trols the nerves and muscles organs of voluntary motion. 



