Impressions arriving at the brain make it enter into activity, just as food falling into the stomach excites it to more abundant secretion of gastric juice. – Pierre Cabanis, translated from French

That’s the classical mind at work, runs fine inside but looks dingy on the surface. – Robert M. Pirsig

Some minds seem almost to create themselves, springing up under every disadvantage and working their solitary but irresistible way through a thousand obstacles. – Washington Irving, The Sketch Book, 1820