is a complex mental experience, and an attempt is made in modern handbooks of psychology to enumerate in detail its elements. But there are cases in which what appears to be the most reasonable conclusion, from a theoretical point of view at least, is of such a nature that even a trained psychologist may hesitate to give his assent to it.

Such an instance is the following: in studying sensations the psychologist distinguishes in them certain aspects, such as their duration, extensity, intensity, and quality. Let us consider only two of these, and let us suppose a man to be conscious at a given moment of two apparently unextended points of color, the one red and the other blue. These the psychologist will recognize as differing in quality, since the colors are not identical; but he may maintain that the intensity of the two color-sensations is the same. In other words, he recognizes the two sensations to be in the one respect identical, and in the other different, just as in Hume's illustration two globes were found to agree in form and not in color.

But if it is reasonable to infer, from the fact that the one globe is perceived to resemble the other in one element and to be dissimilar from it in another-if it is reasonable to conclude from this that each of these experiences is complex, and that this complex is analyzed in the act of comparison, why is it not reasonable to carry over the same reasoning to the two experiences of color which we are discussing? If two color-sensations really have the same intensity while they have not the same quality, it surely follows that intensity and quality are not identical, but are distinct elements, recognized as distinct, at least implicitly, by every one who distinguishes them from each other. Each of the sensations is, then, a complex thing, and not simple, and the successive acts of attention which mark at one time its intensity and at another its quality, are singling out its elements just as attention always singles out certain things in consciousness from certain others, and gives them a relatively greater prominence. But if such sensations are really complex and may be thus separated in thought into their elements, is it not, at least theoretically, possible that the one element might disappear from consciousness altogether, and the other remain undisturbed? In other words, can we not conceive a state of consciousness which would be a consciousness of intensity alone, divorced from quality, or of quality divorced

from intensity? It seems rather appalling to contemplate the possibility of a consciousness of color which has no intensity at all, or of a consciousness of intensity without anything to be intense, but it may be questioned whether we can legitimately arrive at any other conclusion.

It will not do to say that we cannot imagine a color of no intensity at all, and hence the problem may be dismissed. Of course we cannot imagine it as we imagine colored surfaces with all the characteristics which usually mark them. But then we are also unable, when we look at a globe of marble, to separate the color-sensations pure and simple from all the other elements which a past experience of things has furnished us, and hold them up before the mind's eye by themselves. This does not prevent us from distinguishing between them and the rest of the elements constituting our percept, and even believing that in certain consciousnesses - those of infants at the outset of their mental life they may present themselves in a more independent way.

The question is, to be sure, one of theoretical rather than of practical interest, but it is worth while to discuss it, if only because it brings into relief the general method of attaining an analytic knowledge of the contents of consciousness, and emphasizes some of the difficulties connected with it. That there are such difficulties should be frankly admitted, and it should as frankly be admitted that we are at present far from having as complete a knowledge of the contents of consciousness as it is desirable that we should attain. Were it easy to attain to such a knowledge, many disputes which have been carried on with energy through whole centuries, and which we have inherited from our predecessors, would have died away in a remote past. They still live because they have a reason for living. Our most dangerous error lies in supposing it to be easy to describe our own experience, in assuming that the panorama of our mental life unrolls itself before the introspective eye in a clear light, and that the objects which it pictures stand out in unmistakable detail. It is too often forgotten that it is one thing to have an experience, and quite another to reflect upon it. And until one has reflected upon one's experiences with some degree of success, one can only in a restricted sense of the word be said to have "had" them.

CHAPTER IV

THE ELEMENTS IN CONSCIOUSNESS

THE attempt to obtain a general view of the contents of consciousness at first results in a bewildering sense of the variety and complexity of the material which presents itself for examination. But attention soon reveals that there are certain broad distinctions which one may make, and which have been recognized more or less clearly for a long time past.

In the first place, there is the distinction between what is given in the sense and what is reproduced in memory or imagination— a distinction marked by Hume by the use of the terms "impressions" and "ideas."

In a given instance it may not be easy to decide offhand whether a certain experience is to be relegated to the one class or to the other; but in general the distinction is a sufficiently apparent one, and is recognized by the plain man and the scholar alike. Sense-experiences, or at least such of them as usually occupy the attention and stand out in our minds as representatives of their class, possess a vividness denied in most cases to "ideas." I cannot confuse the vivid experience of the pen which I see on the table before me with the shadowy and unsubstantial image of the pencil which I imagine to be lying beside it. The contrast is here very great, and it needs no system of tests to convince me that the two objects fall under different categories. It is true that sense-experiences do not always distinguish themselves so clearly from the images present in the imagination. These images may become very vivid and insistent, and sensations may be extremely vague and obscure. A series of experiments may be needed before it is possible to decide that a certain experience, which is not recognizable at first glance as belonging to the one class or to the other, at least behaves in such a way, stands in such a connection with other experiences, that its proper place may be assigned to it with confidence. If we are wise, we will

not assume that the sheeted ghost which presents itself to our startled eyes when we awake from slumber on the stroke of twelve, is a real phantom, a creature of the sense, merely because it is vividly perceived. We will ask it to present its credentials, prove its claim to respectability of character, and, in short, to conduct itself as a real ghost, claiming a right to be admitted into the circle of real things, should conduct itself. If it fails to establish its claim, we will harden our hearts to its unsubstantial sighs, and banish it to the limbo of the things that are not what they seem.

Fortunately, it is not always necessary to employ such indirect methods in distinguishing between sense-experiences and "ideas." In most instances the two classes fall apart of themselves. Were any man capable of confusing them at all times, his progress in a crowded street would be an eccentric one. We may assume that they may be distinguished directly by most men with sufficient accuracy for the purposes of common life, although we must admit the possibility of error in individual cases, and must make a final appeal, when any dispute arises, to the methods of investigation described by the logician. The attribute of possessing a greater vividness is sufficient to mark out roughly the one class of experiences from the other. If there is any other difference in the experiences themselves, we must turn for information regarding it to the psychologist.

Thus we find the phenomena of our mental life divided into two broad classes. It is generally admitted that one of these must be regarded as, in a sense, copied from the other. It is selfevident that the images in the memory cannot be original creations, but can come into being only when there have been certain experiences in the sense; and it has often been pointed out that there is no flight of the imagination which can carry it out of the region of the elements derived in the first instance from the senses. We may combine these elements in many ways, and we may build up complexes which, as complexes, are new; but further than this it is impossible for us to go. No man who has never seen a color can imagine one, nor can he truly represent to himself any experience into which the element of color enters. These truths are commonplaces of psychology, and it is unnecessary to dwell upon them at length.

There is another broad distinction between elements in consciousness, upon which much emphasis has been laid for a few

generations past. This is the distinction between form and matter, between the arrangement of certain elements in consciousness and those elements themselves.

It is manifestly not a complete description of our experience to say that we find in it such and such sensations of sound, color, touch, pain, etc., and such and such reproductions of these in memory and imagination. These sensations and "ideas" are arranged in divers ways, and stand in manifold relations to each other. These relations exist as truly as do the things which stand in relation, and we constantly recognize them in our reasonings in much the same way.

For example, when we look at three blue spots so arranged that lines joining them with each other would form an equilateral triangle, and then look at three red spots similarly arranged, we recognize a sameness and a difference, just as we do when we compare a globe of white marble with a globe of black. We see that there is identity in the formal element in our experience and diversity in the material. And when we compare three blue spots arranged as above mentioned with three similar blue spots arranged in a row, we find the material element to be identical, and the formal to be diverse. In such a case there is no difficulty in distinguishing between the two elements, and in picking out the one from the other. We are evidently dealing with a complex and are analyzing it into its constituents, and the difficulty of holding relations separately before the attention, and obtaining a clear view of them, appears to be only an instance of the difficulty which always confronts us when we attempt to grasp, in an analytic way, elements of the complexes which constitute our experience.

The material elements in consciousness may either be present simultaneously, or they may be successive. In this distinction we have the two most general classes into which the ways of arranging them may be divided. The former class it is convenient to subdivide further, for not all those material elements which appear in consciousness simultaneously stand to each other in what we call spacial relations. These latter form a special class, a form of coexistence of such importance that it is sometimes overlooked that there are coexistences of a different kind. Relations of succession are those classed together as temporal.

It is important to bear in mind the fact that these ways of