Page:The Harveian oration 1912.djvu/29

Rh insanity thus becoming a cancer-like mood of the cells of thought, as well as a mood of growth.

Admittedly there is plenty of gross disease in the brain, but it is as nothing compared with the many forms of misdirected energy that we call insanity. I would venture to call as witness the late Dr. Hughlings Jackson on this point, for, starting out on his work with inferences concerning function based upon definite lesions, he passed onwards to the wider sphere to which I say pathology is turning, where disease is the outcome of misdirected function. There is much of what we call insanity that is of this character: a man of impulse or emotion indulges his weakness—or his strength, is it?—and increases it. Little by little he loses his control, and the balance sinks to mania. A lethargic mind refuses first one fence and then another and another, until all really effortful response fails, and a mere sensori-motor existence is the result. Take also the class of functional paralyses where movement and sensation suddenly disappear : surely thus to close up the book of one’s existence over so large an area must profoundly interfere with the trophic changes in the tissues, and, if protracted enough, lead to stasis, condensation, atrophy, all of them active instigators of structural change. There is much hope in this way of looking at things. How largely the world of the insane exists because it has harboured the fateful presentiment that thus it must be! It were better to spend one’s time in perfecting some mechanism of the will that should damp down such mendacious forecasts.