difficulty by running into the fog banks of mysticism. To explain anything we must first of all have a clear conception of terms, and the appeal must be not to fancy but to definition. An hypothesis like the one before us, suggesting what no one can conceive, can give us no explanation. It is as if when a strange object passes the window a mother should answer her child's inquiry, "What is it?" by saying, "It is a centaur." This answer might arouse the imagination of the child, might stir its curiosity, but it would bring the child no knowledge, for it has never seen a centaur, does not know how it looks, acts, or what it is or can do. The answer simply refers the child to an object beyond its experience and hence is no answer at all. The same is true when in explaining facts of consciousness we are referred to a new kind of substancea double-faced somewhat, on the one side matter and on the other mind. We have here a philosophical centaur, a construction of the imagination, not a matter which experience has verified. We might as well speak of the length of a thought, or the color of a volition, as of "a mind atom," or matter with a double side. We are playing with words, taking them out of their known meanings and putting into them qualities and meanings at will, stuffing them with hypothetical values. If this is permissible we can prove anything that the moon is made of green cheese, or the reality of Santa Claus and the bogy man. A second objection is that, in this theory of monism, the relation of the mind side and the matter side of the atom, or in man of the brain series and the thought series, is not satisfactorily defined. There are three possible hypotheses, each of which we shall show is inadequate namely, thought and feeling are effects of brain action, or they attend brain activity, or they are aspects or phenomena of brain substance. To the hypothesis that thought and feeling are effects of brain activity we have, first, the objection that it is in contradiction to the scientific doctrine of the conservation of energy. It is a law of physics that energy can only pass into terms of itself; that is, into some other form of physical energy. Hence, if thought is produced by the specific grouping of molecules of the brain, it follows that thought must be assimilated to causation in the physical world, which means that thought must be material or the law of

the correlation and conservation of energy is broken. For thought cannot be produced by the brain molecules without the expenditure of energy, and each mental effect must represent a certain loss of nervous force. The energy which has thus been used must disappear from the physical realm, must be lost to the physical series. It cannot be returned since, by hypothesis, thought is an effect and not a cause- -that is, it cannot enter the chain of effects and be a cause to what follows it. The series stops with the production of thought; for, if thought can react on the physical series, then the physical series is not independent, and we have as much evidence that the mental can affect the physical as that the physical can affect the mental, which is the very point the materialist's theory is framed to deny. It cannot admit, without committing suicide, that thought, feeling, and volition can count in the course of events as well as physical forces. The energy therefore which goes to produce mental effects is lost and cannot be returned to the physical series; which, as we have said, is to sacrifice the principle of the conservation of energy in the interest of a new and hypothetical theory of matter for which we have no other proof than that we hope it will help us solve a difficult problem. But besides this objection we have another equally serious: the qualities of matter and mind are entirely different, and the passage from one to the other is unthinkable. Between the sentient and the nonsentient, between thought and motion, there is a great gulf fixed and no man has yet been able to bridge it. Matter has form, solidity, position, but thoughts and feelings have none of these. The one order of facts is quantitative and the other is qualitative. Modern science is to-day no nearer making matter and mind commensurable than was Democritus twenty-four hundred years ago. We can explain sound, light, and heat on the physical plane, but not the sensations of sound and light and heat. In the words of Professor Tyndall: "Here, however, the methods pursued in mechanical science come to an end; and if asked to deduce from the physical interaction of the brain molecules the least of the phenomena of sensation, or thought, we must acknowledge our helplessness. Between molecular mechanics and consciousness is interposed a fissure over which the ladder of physical reasoning is

incompetent to carry us." Dr. Maudsley, who has striven with all his power to break down the fence which separates the physical from the mental, has been forced to give up the task and admit that the observation of physical objects and the more careful study of nerves and brain cannot give us the least direct information about "feelings, desires, volitions, and ideas." Even Herbert Spencer in one place frankly admits: "That a unit of feeling has nothing in common with a unit of motion becomes more and more manifest when we bring the two into juxtaposition."

With these difficulties in the way it is plain that we cannot hold that consciousness is an effect of brain activity, and in explaining the relation between the two we must seek some other way out. This way is found by some in claiming that thought is not caused by brain movement, but attends it. "The physical series is self-contained and independent. It suffers no loss and no irruption." The mental series is "the subjective shadow which attends the physical series." "Physical energy is not expended in producing thought, but in producing physical combinations which have a thought face." In the words of Professor Huxley: "Our mental conditions are simply the symbols in consciousness of the changes which take place automatically in the organism." Herbert Spencer says that mental phenomena are the "inner side of molecular motion in the brain;" they are the shadows cast by certain combinations of molecular activities. It does not take much pondering of this explanation to see that, while it is easy to state, it is exceedingly hard to understand. We know what a shadow is, for we have seen it many a time, but a subjective shadow of molecular activities of brain is something of which only a great imagination can get any conception. The same is true of physical combinations having a thought face, or consciousness being a symbol of organic processes. Mr. Spencer might say that the terms are figurative; certainly figures, especially when used in defining theories, should contain some meaning, but we are confident that these figures do not represent any idea which comes to us in thinking of the implications involved in brain molecules and their movements. They are simply magic terms with which Spencer, Huxley, and their class conjure with difficulties. They

give no clear idea of the relation which exists between the thought series and the physical series, but only obscure the problem. They do not explain why one combination of molecular activities is attended by thought and feeling and another is not; why there is any order in the mental series, and thought is not chaotic; why some movements have, as their subjective side, ideas, others feelings, and others volitions; or how, if the two faces of matter, the mind face and the force face, do not affect each other, it comes about that the mind face side is shadowed forth by physical movements of the brain; nor do they show how the unity of the atom can be retained if it is endowed with a thought side and a thing side. There must be something in certain molecular movements which elicits and makes manifest the thought series, and this makes thought an effect of matter, or puts the cause back in some hidden ground of mystery in matter itself, which is equivalent to abandoning the problem; or at best it is giving "a double movement to matter, a physical and a thought movement," which "leaves it doubtful whether matter as moving or matter as thinking is the true reality, or whether there may be something deeper than both," either alternative of which is "fatal to the assumed selfsufficiency of the physical series."

But may we not state the relation of the thought series and the physical series differently, and affirm that thought is an aspect or phenomenon of matter? Professor B. P. Bowne, in a lecture before the American Institute of Christian Philosophy, has replied to this hypothesis as follows:

This suggestion does seem to help us a little until we remember that the phenomenon imply not only something which appears but a subject to which it appears. When, then, the thought side of matter is said to be phenomenal the question at once emerges, What is the subject and where the consciousness for which the phenomena exist? For the materialist there is no such subject. Yet so natural is the thought of self that we never divest ourselves of it even when denying it. When the materialist views the brain as a thinking machine he always tacitly assumes himself as a reading machine which reads off the result. When we are told that nerve motions have thoughts for their inner face, a self is always supplied for whom the thought exists. Materialistic statements tacitly assume back of the organism which conducts the neural process a looker-on who tells of the processes and interprets their meaning. Thus thought is said to be a sign of nervous process; but for whom does the sign exist? The out

sider could not see the thought, but only the nerve movements. For whom, then, is the thought a sign? For the thinking self, of course. Thus the self which the materialist labors to destroy peers complacently through the very arguments which are framed for its destruction.

Having examined the grounds on which the theory of mind in question rests, we wish to append a few arguments of a more positive nature showing why consistent thinking must reject it.

1. All knowledge we have, both of the outer and the inner world, is through consciousness, and in its analysis we find a subject as much an element of its existence as an object, or, to use Professor James's expression, the "I" is as real as the "me." Hume affirmed the contrary, and said: "For my part, when I enter most intimately into what I call myself I always stumble on some particular perception or theory of heat or cold, light or shade, love or hate, pain or pleasure. I never catch myself at any time without a perception, and can never observe anything but a perception." With this idea President Jordan and all who rep resent the "sum" idea of mind must agree. But let us look at Hume's statement somewhat carefully and see if he does not affirm what he denies. What does he mean when he says "I," and "catch myself," and "for my part," and "I stumble," and "I call"? When he declares, "I never catch myself without a perception," his words clearly imply that he catches himself in a percep tion; for he tells us plainly he observes the perception, and how can an observation be made unless there be some one to do the observing? If we can affirm we never find ourselves without a perception, we may also say a perception never exists without our finding it. The fact is, self-consciousness is a factor in all consciousness, and the principal thing we have to explain is not a thought or a feeling, but the fact that I think and I feel. Whoever takes the ego out of consciousness destroys it; for it exists only in the antithesis of subject and object. When we study any facts we study them not as abstracts, but as the self knows them. Thoughts, feelings, and desires are not mere successive effects but experiences; and an experience is only a word we use to express a state of self. An experience is not something which occurs in vacuo, but only in the existing self, or, in other words, there is no