id="Page_24" class="x-ebookmaker-pageno" title="[Pg 24]"/> elements of the other contents of consciousness. In other words modern psychology has recognized that the volitions and emotions and feelings and judgments, and the whole stream of inner life, are made up of sensations. Millions of sensations in all degrees of vividness and clearness, of intensity and fusion, in endless manifoldness of rhythms and relations constitute their whole content. It is a discovery quite similar to the one which chemistry made when it found that the same elements which are part of the inorganic substances are also the only possible elements of the organic world.

From a strictly psychological standpoint, the ideas and the not-ideas contain thus nothing but sensations. Their grouping, their shading, their combination, their succession decide whether we have before us a perception or an imagination, a volition or an emotion. What are we ourselves then for the psychologist? Evidently we ourselves belong also to the inner experiences which we know; and psychology has succeeded in analyzing this idea of our own self just in the same way as it analyzes our idea of the moon. In this analysis, psychology finds its idea of the self as a content of consciousness crystallized about the sensations from the body. Every one of our bodily activities is represented in our consciousness by movement sensations, and these sensations form the core of the complex aggregate which develops into the idea of ourselves. Organic sensations from our inner organs, pain sensations and pleasure sensations fuse with the movement sensations, and the whole complex shapes itself slowly into the idea of the personality of the self in contrast to the idea of other personalities. We ourselves are for ourselves a complex combination of sensations; and yet all our feelings and emotions and volitions are only a part of it. Psychology thus necessarily considers those experiences of feeling and will and character simply as changes in the midst of that central experience of personality which is itself made up of bodily sensations. Each bit of will and emotion must be decomposed into its finest elements. There is no passing mood, and no floating half-thought in our mind, no dream and no intuition, no slightest change of attention, no instinct and desire which cannot be analyzed thus into its sensation elements or rather which must not be analyzed, if we are to describe it at all, and that means if we are to give a psychological account. Psychology is endlessly far from this ideal to-day. It has been claimed, not without justice, that psychology has reached to-day only the level which physics attained in the seventeenth century; but psychology must insist that its ideal lies in this direction. No one takes a real psychological view of the human mind who does not understand this endless complexity of the material, and who does not see that even the simplest mental state practically presents a most complex problem to scientific analysis. The physician who really aims towards scientifically exact influence on the human mind has reached the first step of his preparation as soon as he understands that the content of consciousness is composed of hundreds of thousands of elements. To treat the mind as if there were only a few large pieces, one thing called memory and one thing called will and one called emotion and so on, is as if a surgeon were to perform an operation, knowing that there are arms and legs, but not knowing the ramifications of the nerves and blood-vessels which his knife may injure. Yet the description of these complex facts is only the beginning of psychology. We saw that the real aim is their explanation.

III

MIND AND BRAINContents

The central aim of the psychologist must be to explain the mental facts. It is not sufficient to describe the procession of mental experiences in us, we must understand the causes which determine that now this and now that appears and disappears, and appears just in this combination of elements. The astronomer is not satisfied with describing the stars, he wants to explain their movements and to determine which movements are to be expected. The psychologist, like the naturalist, aims towards explanation, and it is this demand which forces him to look from the psychical facts to the physical ones, from the mind to the brain. He is under an illusion if he fancies that he can explain mental facts by themselves. The purposive mind has its connection in itself, the causal psychological mind demands for its connection the body. To understand this necessity is the first step towards understanding the relation of mind and brain.

The psychologist's problem of explanation is in one way entirely different from that of the physicist. The physicist finds a world of an unlimited number of atoms which are ultimately conceived as all alike, but each one in a different place, and all the changes in the universe, the movements of the stars, the waves of the ocean, are to be explained by the causal connections of the movements of these atoms. The psychologist, on the other hand, finds an endless manifoldness of elements which are not in space, and which have no space form whatever. My will is neither triangular nor oval; my emotion is neither shorter than five feet nor longer; my memory image of a melody has no thickness and no tallness; my contents of consciousness are as such not in space; their elements cannot pass through any space movements like the atoms of the physicist. Instead of it, the psychical atoms, the sensations, have different qualities, are blue and green, and cold and warm, and sweet and sour, and toothache and headache. The changes which go on in such a system are thus not changes of position and movements, but changes in kind and strength and vividness and fusion; and exactly such changes are the processes which the psychologist wants to explain. He wants to make us understand why this idea grows up and the other fades away, why this impression stands out with clearness as an attended object while the other lacks vividness and disappears, why this volition grows out of that emotion, why this feeling leads to this imaginative thought.

The first step towards such explanation is, of course, in psychology, as in all other sciences, the careful observation of regularities. It quickly leads us to formulate some general laws. Psychology has known, for instance, for two thousand years, that if we have perceived two things together, and later we see the one again, the new perception brings us a memory image of the other thing. If we saw a man's face and heard at the same time his name, seeing his face may later awaken in us the memory of his name, or the hearing of his name may later awaken in us a reproduced memory image of his face. On such a basis, for instance, we formulate some general laws of association of ideas, and as soon as we have such laws laid down, we consider the appearance of such a memory image by association as sufficiently explained. We feel that it gives us sufficient basis to predict that in the future this idea will stir up in us the other idea. Psychology has formulated plenty of such general statements, and they serve well for a first orientation.

Yet can this ever be considered as a last word of scientific explanation of psychical facts? Can psychology really in this way reach an ideal similar to that of scientific astronomy or chemistry? Would the scientist of nature ever be satisfied with this kind of explanation, which is nothing but