Take the case of the disease known as General Paresis, officially called Dementia Paralytica. This disease is caused by syphilis and is one of its late results. The pathological changes are widespread throughout the brain but may at the onset be confined mostly to the frontal lobes. The very first change may be--and usually is--a change in character! The man hitherto kind and gentle becomes irritable, perhaps even brutal. One whose sex morals have been of the most conventional kind, a loyal husband, suddenly becomes a profligate, reckless and debauched, perhaps even perverted. The man of firm purposes and indefatigable industry may lose his grip upon the ambitions and strivings of his lifetime and become an inert slacker, to the amazement of his associates. Many a fine character, many a splendid mind, has reached a lofty height and then crumbled before the assaults of this disease upon the brain. Philosopher, poet, artist, statesman, captain of industry, handicraftsman, peasant, courtesan and housewife,--all are lowered to the same level of dementia and destroyed character by the consequences of the thickened meninges, the altered blood vessels and the injured nerve cells. Now and then one is fortunate enough to treat with success an early case of General Paresis. And then the reversed miracle takes place, unfortunately too rarely! The disordered mind, the altered character, leaps upward to its old place,--after being dosed by the marvelous drug Salvarsan, created by the German Jewish scientist, Paul Ehrlich. Of extraordinary interest are the rare cases of loss of personal identity seen after brain injury, say in war. A man is knocked unconscious by a blow and upon restoration of consciousness is separated from that past in which his ego resides. He does not know his history or his name, and that continuity of the "self" so deeply prized and held by all religions to be part of his immortality is gone. Then after a little while, a few days or weeks, the disarranged neuronic pathways reestablish themselves as usual,--and the ego comes back to the man. One might cite the feeble-mindedness that results from meningitis, brain tumor, brain abscess, brain wounds, etc., as further evidence of the dependence of mind upon brain, of its status as a function of brain. No philosopher seriously doubts that equilibrium and movement are functions of the brain, and yet to prove this there is no evidence of any other kind than that cited to prove the relationship of mind to brain.[1] And what applies to the intelligence applies as forcibly to character, for purpose, emotion, mood, instinct and will are altered with these diseases.