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.
[1] Except that equilibrium does not itself judge of its relationship to brain, whereas mind is the sole judge of its relationship and dependence on brain. Since everything in the world is a mental event, mentality cannot be dependent upon anything, and everything depends upon mind for its existence, or at least its recognition. But we get nowhere by such "logic" gone mad. Apply the same kind of reasoning to brain-mind, body-mind relationship which anatomists and physiologists apply to other functions, and one can no longer separate body and mind.
Interesting as is the relationship between mind and character and the brain, it is at the present overshadowed by the fascinating relationship between these psychical activities and the bodily organs. What I am about to cite from medicine and biology is part of the finest achievements of these sciences and hints at a future in which a true science of mind and character will appear.
Certain of the glands of the body are described as glands of internal secretions in that the products of their activity, their secretions, are poured into the blood stream rather than on the surface of the body or into the digestive tract. The most prominent of these glands, all of which are very small and extraordinarily active, are as follows:
The Pituitary Body (Hypophysis)--a tiny structure which is situated at the base of the brain but is not a part of that organ.
The Pineal Body (Epiphysis)--a still smaller structure, located within the brain substance, having, however, no relationship to the brain. This gland has only lately acquired a significance.
Descartes thought it the seat of the soul because it is situated in the middle of the brain.
The Thyroid gland, a somewhat larger body, situated in the front of the neck, just beneath the larynx. We shall deal with this in some detail later on.
The Parathyroids, minute organs, four in number, just behind the thyroid.
The Thymus, a gland placed just within the thorax, which reaches its maximum size at birth and then gradually recedes until at twenty it has almost disappeared.
The Adrenal glands, one on each side of the body, above and adjacent to the kidney. These glands, which are each made up of two opposing structures, stand in intimate relation to the sympathetic nervous system and secrete a substance called adrenalin.
The Sex organs, the ovary in the female and the testicle in the male, in addition to producing the female egg (ovum) and the male seed (sperm), respectively, produce substances of unknown character that have hugely important roles in the establishment of mind, temperament and sex character.
