It seems a gratuitous labor to criticise such statements as these in detail. There are no glands the secretions of which are not as unequivocally material as are the glands themselves. This means that such secretions can be captured and analyzed; the chemical elements of which they are composed can be enumerated. They are open to inspection in precisely the same way as are the glands which secrete them.
Does it seem reasonable to maintain that thoughts and feelings are related to brains in this way? Does the chemist ever dream of collecting them in a test tube, and of drawing up for us a list of their constituent elements? When the brain is active, there are, to be sure, certain material products which pass into the blood and are finally eliminated from the body; but among these products no one would be more surprised than the materialist to discover pains and pleasures, memories and anticipations, desires and volitions. This talk of thought as a "secretion" we can afford to set aside.
Nor need we take much more seriously the seemingly more sober statement that thought is a "function" of the brain. There is, of course, a sense in which we all admit the statement; minds are not disembodied, and we have reason to believe that mind and brain are most intimately related. But the word "function" is used in a very broad and loose sense when it serves to indicate this relation; and one may employ it in this way without being a materialist at all. In a stricter sense of the word, the brain has no functions that may not be conceived as mechanical changes,—as the motion of atoms in space,—and to identify mental phenomena with these is inexcusable. It is not theoretically inconceivable that, with finer senses, we might directly perceive the motions of the atoms in another man's brain; it is inconceivable that we should thus directly perceive his melancholy or his joy; they belong to another world.
56. SPIRITUALISM.—The name Spiritualism is sometimes given to the doctrine that there is no existence which we may not properly call mind or spirit. It errs in the one direction as materialism errs in the other.
One must not confound with this doctrine that very different one, Spiritism, which teaches that a certain favored class of persons called mediums may bring back the spirits of the departed and enable us to hold communication with them. Such beliefs have always existed among the common people, but they have rarely interested philosophers. I shall have nothing to say of them in this book.
There have been various kinds of spiritualists. The name may be applied to the idealists, from Berkeley down to those of our day; at some of the varieties of their doctrine we have taken a glance (sections 49, 53). To these we need not recur; but there is one type of spiritualistic doctrine which is much discussed at the present day and which appears to appeal strongly to a number of scientific men. We must consider it for a moment.
We have examined Professor Clifford's doctrine of Mind-stuff (section 43). Clifford maintained that all the material things we perceive are our perceptions—they are in our consciousness, and are not properly external at all. But, believing, as he did, that all nature is animated, he held that every material thing, every perception, may be taken as a revelation of something not in our consciousness, of a mind or, at least, of a certain amount of mind-stuff. How shall we conceive the relation between what is in our mind and the something corresponding to it not in our mind?
We must, says Clifford, regard the latter as the reality of which the former is the appearance or manifestation. "What I perceive as your brain is really in itself your consciousness, is You; but then that which I call your brain, the material fact, is merely my perception."
This doctrine is Panpsychism, in the form in which it is usually brought to our attention. It holds that the only real existences are minds, and that physical phenomena must be regarded as the manifestations under which these real existences make us aware of their presence. The term panpsychism may, it is true, be used in a somewhat different sense. It may be employed merely to indicate the doctrine that all nature is animated, and without implying a theory as to the relation between bodies perceived and the minds supposed to accompany them.
What shall we say to panpsychism of the type represented by Clifford? It is, I think, sufficiently answered in the earlier chapters of this volume:—