ABSTRACT
Physiological Introduction. It is customary to accompany a general account of the working of the mind with a description of the structure and functions of the nervous system and especially of the brain. There is some sense in this, for mental processes as we know them are certainly related to brain processes; but the relationship is not so simple as it is commonly assumed to be. Considerable injury may occur to the brain without any resulting disorder of mind, but it is not yet sufficiently realized that disorder of mind frequently exists without any discoverable alteration in the brain.
