It is just forty years since I first ventured to call in question the accepted doctrines of the causation of nervous diseases. In an article in the British and Foreign Medical and Chirurgical Review, an excellent quarterly now long defunct, I likened the imagination of physicians in this respect to the imagination of that fortunate sailor to whom was granted (nowadays we should say who was given) the fairy privilege of having three wishes fulfilled. After he had secured all the rum in the world and all the tobacco in the world by his first two wishes, he could think of nothing further to desire than “a little more rum.” So physicians, after they had attributed every known nervous disease to sexual excess and syphilis, had no explanation of a new disease to offer beyond a little more sexual excess. The only nervous diseases that were not then attributed partly or wholly to syphilis were tabes and general paralysis. Some five-and-twenty years ago, when an eminent physician was about to lecture upon the causes of insanity, I hazarded the conjecture that we should hear a good deal about masturbation, and I had no reason to repent of my prophecy. We may be pardoned a little natural exultation when we contrast the present state of ætiological doctrine with that which prevailed in those dark ages. We had then no more reason for our belief than Aristotle had for the belief that all heavy bodies tend to the centre of the universe, but now we know that the mental diseases that we used fondly to ascribe to sexual excess and syphilis are, in fact, due to repressed complexes and infantile incestuous longings. How foolish were our predecessors! How enlightened are we!