H. G. A. to H. M.

“What is the brain?”

The brain is the organ from whose action arises all that class of phenomena which we term Mind: in which I include all our sensations, perceptions, emotions, judgments and intuitions; consciousness, will, and certain forces which tend to regulate, stimulate and control the other functions of the body. This, you perceive, is giving to the brain a larger sphere of action than is assigned to it in the works on phrenology. I differ also from phrenologists in this; that I consider consciousness, will, pleasing or painful sensations, &c., to be distinct faculties, and the functions of special organs. You know the brain; I need therefore only remind you that there are, in fact, two brains: the cerebrum occupying the larger portion of the skull, and the cerebellum in a separate compartment, beneath the posterior lobe of the cerebrum, occupying the space behind the ears. It has happened to me to be able to demonstrate that this lesser brain is not what Gall supposed it to be; that is, the organ of the amative propensity: but the organ of that class of powers which might perhaps, for distinction's sake, be termed the physico-functional powers; or those powers having a more immediate relation to the bodily conditions—the muscular power, and other purely bodily relations, secretions, &c. But, whatever importance I may attach to the knowledge of the functions of this and of some other parts, I trust you will not consider it presumption in me, or that I wish in any way to force these views upon others, or to take from the value of their labours.