The Greeks say that there are three methods of discharging the genial secretion of which I have spoken. They thought perhaps that their methods tended to secrete it, but this I do not believe altogether, or without a qualm. For the manifestation of force implies force, and this force must have come from somewhere.
Easier I find it to say "subconsciousness" and "secretion" than to postulate an external reservoir, to extend my connotation of "man" than to invent "God." However, parsimony apart, I find it in my experience that it is useless to flog a tired horse. There are times when I am absolutely bereft of even one drop of this elixir. Nothing will restore it, neither rest in bed, nor drugs, nor exercise. On the other hand, sometimes when after a severe spell of work I have been dropping with physical fatigue, perhaps sprawling on the floor, too tired to move hand or foot, the occurrence of an idea has restored me to perfect intensity of energy, and the working out of the idea has actually got rid of the aforesaid physical fatigue, although it involved a great additional labour.
Exactly parallel (nowhere meeting) is the case of mania. A madman may struggle against six trained athletes for hours, and show no sign of fatigue. Then he will suddenly collapse, but at a second's notice from the irritable idea will resume the struggle as fresh as ever. Until we discovered "unconscious muscular action" and its effects, it was rational to suppose such a man "possessed of a devil"; and the difference between the madman and the genius is not in the quantity but in the quality of their work. Genius is organized, madness chaotic. Often the organization of genius is on original lines, and ill-balanced and ignorant medicine-men mistake it for disorder.
Time has shown that Whistler and Gauguin "kept rules" as well as the masters whom they were supposed to be upsetting.