are organic, are functions of the organism and do not exist independently of it. I emphasize "practical" in relation to causation because it would be idle for us here to enter into the philosophy of cause and effect. Such discussion is not taken seriously by the very philosophers who most earnestly enter into it.

[1] William James in Volume 1 of his "Psychology" gives an interesting resume of the theories that consider the relationship of mind (thought and consciousness) to body. He quotes the "lucky" paragraph from Tyndall, "The passage from the physics of the brain to the corresponding facts of consciousness is unthinkable. Granted that a definite thought and a definite molecular action in the brain occur simultaneously; we do not possess the intellectual organ, or apparently any trace of the organ which would enable us to pass by a process of reasoning from one to the other." This is the "parallel" theory which postulates a hideous waste of energy in the universe and which throws out of count the same kind of reasoning by which Tyndall worked on light, heat, etc. We cannot understand the beginning and the end of motion, we cannot understand causation. Probably when Tyndall's thoughts came slowly and he was fatigued he said—"Well, a good cup of coffee will make me think faster." In conceding this practical connection between mind and body, every "spiritualist" philosopher gives away his case whenever he rests or eats.

The statement that mind is a function of the organism is not necessarily "materialistic." The body is a living thing and as such is as "spiritualistic" as life itself. Enzymes, internal secretions, nervous activities are the products of cells whose powers are indeed drawn from the ocean of life.

To prove this statement, which is a cardinal thesis of this book, I shall adduce facts of scientific and facts of common knowledge. One might start with the statement that the death of the body brings about the abolition of mind and character, but this, of course, proves nothing, since it might well be that the body was a lever for the expression of mind and character, and with its disappearance as a functioning agent such expression was no longer possible.

It is convenient to divide our exposition into two parts, the first the dependence upon proper brain function and structure, and the second the dependence upon the proper health of other organs. For it is not true that mind and character are functions of the brain alone; they are functions of the entire organism. The brain is simply the largest and most active of the organs upon which the mental life depends; but there are minute organs, as we shall see, upon whose activity the brain absolutely depends.

Any injury to the brain may destroy or seriously impair the mentality of the individual. This is too well known to need detailed exposition. Yet some cases of this type are fundamental in the exquisite way they prove (if anything can be proven) the dependence of mind upon bodily structure.

In some cases of fracture of the skull, a piece of bone pressing upon the brain may profoundly alter memory, mood and character. Removal of the piece of bone restores the mind to normality. This is also true of brain tumor of certain types, for example, frontal endotheliomata, where early removal of the growth demonstrates first that a "physical" agent changes mind and character, and second that a "physical" agent, such as the knife of the surgeon, may act to reestablish mentality.

In cases of hydrocephalus (or water on the brain), where there is an abnormal secretion of cerebro-spinal fluid acting to increase the pressure on the brain, the simple expedient of withdrawing the fluid by lumbar puncture brings about normal mental life. As the fluid again collects, the mental life becomes cloudy, and the character alters (irritability, depressed mood, changed purpose, lowered will); another lumbar puncture and presto!—the individual is for a time made over more completely than conversion changes a sinner,—and more easily.

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