P. S. I forgot to notice your statement—“not through the physical fact of nerve-tissue,” etc.
All thinking—all, without exception—is alteration of nerve-substance; either temporary motion or motion making by countless repetition alterations that are permanent. Physiologically, “thought” is a very complex vibration in nerve-tissue. There is no other meaning whatever in science for “thought.” For “thought” is a perception of relations in preëxisting states of consciousness, and those are bundles of sensations. What “sensation” is, no man knows. That is the dark spot in the retina of consciousness. But there is no proof that sensation exists apart from cell-substance.
To speak of an “ideal process” outside of vibration in nervous substance is therefore like saying that 5 times 5 = 918. It is a total denial of all science on the subject. An idea is a bundle of sensations, and a sensation is coincident with a movement in cerebral cells. Without the movement there is no sensation,—not at least in the brain. We do not know the ultimate of sensation, but thoughts and ideas only mean complex combinations of sensations impossible outside of nerve-substance so far as we know.
Of course if you mean by culture from outside the transmission of civilization from one race to another,—then there has been enormous alteration of cerebral structure. Such alteration is even now going on in Japan, and causes yearly hundreds of deaths.
The brain of the civilized man is 30 p.c. heavier than that of the savage; and the brain of the 19th century much larger than that of the 16th (see Broca). A striking fact of evolution is brain-growth. The early mammals were remarkable for the smallness of their brains. Man’s nervous structure is, of course, the most powerful of all. Cut out of the body, it is found to weigh, as a total, double that of a horse. For mind signifies motion, force,—the more powerful the mind the greater the forces evolved. Perhaps the nervous system of a whale might weigh more than that of a man as a total mass, but not nearly so much in parts corresponding with mental differences. Nevertheless the changes effected by progress in the brain are chiefly visible in the direction of increasing complexity rather than in bulk. The study of brain-casts promises to develop some interesting facts.
TO BASIL HALL CHAMBERLAIN
Kōbe, April, 1895.
Dear Chamberlain,—In one of your recent letters, which charmed me by its kindness,—though I did not dwell on the pleasure given me, because I was so immediately occupied in discussing my psychical hobby,—you asked me: “How could I expect to hit the public more than I have done?”
Well, not with a book on Japan, perhaps; but I must do better some day with something, or acknowledge myself a dead failure. I really think I have stored away in me somewhere powers larger than those I have yet been able to use. Of course I don’t mean that I have any hidden wisdom, or anything of that sort; but I believe I have some power to reach the public emotionally, if conditions allow.