18. THE EXISTENCE OF MATERIAL THINGS.—One difficulty seems to remain and to call for a solution. We all believe that material things exist when we no longer perceive them. We believe that they existed before they came within the field of our observation.
In these positions the man of science supports us. The astronomer has no hesitation in saying that the comet, which has sailed away through space, exists, and will return. The geologist describes for us the world as it was in past ages, when no eye was opened upon it.
But has it not been stated above that the material world is an order of experiences? and can there be such a thing as an experience that is not experienced by somebody? In other words, can the world exist, except as it is perceived to exist?
This seeming difficulty has occasioned much trouble to philosophers in the past. Bishop Berkeley (1684–1753) said, "To exist is to be perceived." There are those who agree with him at the present day.
Their difficulty would have disappeared had they examined with sufficient care the meaning of the word "exist." We have no right to pass over the actual uses of such words, and to give them a meaning of our own. If one thing seems as certain as any other, it is that material things exist when we do not perceive them. On what ground may the philosopher combat the universal opinion, the dictum of common sense and of science? When we look into his reasonings, we find that he is influenced by the error discussed at length in the last section—he has confused the phenomena of the two orders of experience.
I have said that, when we concern ourselves with the objective order, we abstract or should abstract, from the relations which things bear to our senses. We account for phenomena by referring to other phenomena which we have reason to accept as their physical conditions or causes. We do not consider that a physical cause is effective only while we perceive it. When we come back to this notion of our perceiving a thing or not perceiving it, we have left the objective order and passed over to the subjective. We have left the consideration of "things" and have turned to sensations.
There is no reason why we should do this. The physical order is an independent order, as we have seen. The man of science, when he is endeavoring to discover whether some thing or quality of a thing really existed at some time in the past, is not in the least concerned to establish the fact that some one saw it. No one ever saw the primitive fire-mist from which, as we are told, the world came into being. But the scientist cares little for that. He is concerned only to prove that the phenomena he is investigating really have a place in the objective order. If he decides that they have, he is satisfied; he has proved something to exist. To belong to the objective order is to exist as a physical thing or quality.
When the plain man and the man of science maintain that a physical thing exists, they use the word in precisely the same sense. The meaning they give to it is the proper meaning of the word. It is justified by immemorial usage, and it marks a real distinction. Shall we allow the philosopher to tell us that we must not use it in this sense, but must say that only sensations and ideas exist? Surely not. This would mean that we permit him to obliterate for us the distinction between the external world and what is mental.
But is it right to use the word "experience" to indicate the phenomena which have a place in the objective order? Can an experience be anything but mental?
There can be no doubt that the suggestions of the word are unfortunate—it has what we may call a subjective flavor. It suggests that, after all, the things we perceive are sensations or percepts, and must, to exist at all, exist in a mind. As we have seen, this is an error, and an error which we all avoid in actual practice. We do not take sensations for things, and we recognize clearly enough that it is one thing for a material object to exist and another for it to be perceived.
Why, then, use the word "experience"? Simply because we have no better word. We must use it, and not be misled by the associations which cling to it. The word has this great advantage: it brings out clearly the fact that all our knowledge of the external world rests ultimately upon those phenomena which, when we consider them in relation to our senses, we recognize as sensations. We cannot start out from mere imaginings to discover what the world was like in the ages past.
It is this truth that is recognized by the plain man, when he maintains that, in the last resort, we can know things only in so far as we see, touch, hear, taste, and smell them; and by the psychologist, when he tells us that, in sensation, the external world is revealed as directly as it is possible that it could be revealed. But it is a travesty on this truth to say that we do not know things, but know only our sensations of sight, touch, taste, hearing, and the like.[1]
[1] See the note on this chapter at the close of the volume.
CHAPTER V
APPEARANCES AND REALITIES
19. THINGS AND THEIR APPEARANCES.—We have seen in the last chapter that there is an external world and that it is given in our experience. There is an objective order, and we are all capable of distinguishing between it and the subjective. He who says that we perceive only sensations and ideas flies in the face of the common experience of mankind.
But we are not yet through with the subject. We all make a distinction between things as they appear and things as they really are.
If we ask the plain man, What is the real external world? the first answer that seems to present itself to his mind is this: Whatever we can see, hear, touch, taste, or smell may be regarded as belonging to the real world. What we merely imagine does not belong to it.
That this answer is not a very satisfactory one occurred to men's minds very early in the history of reflective thought. The ancient skeptic said to himself: The colors of objects vary according to the light, and according to the position and distance of the objects; can we say that any object has a real color of its own? A staff stuck into water looks bent, but feels straight to the touch; why believe the testimony of one sense rather than that of another?
Such questionings led to far-reaching consequences. They resulted in a forlorn distrust of the testimony of the senses, and to a doubt as to our ability to know anything as it really is.
Now, the distinction between appearances and realities exists for us as well as for the ancient skeptic, and without being tempted to make such extravagant statements as that there is no such thing as truth, and that every appearance is as real as any other, we may admit that it is not very easy to see the full significance of the distinction, although we are referring to it constantly.
For example, we look from our window and see, as we say, a tree at a distance. What we are conscious of is a small bluish patch of color. Now, a small bluish patch of color is not, strictly speaking, a tree; but for us it represents the tree. Suppose that we walk toward the tree. Do we continue to see what we saw before? Of course, we say that we continue to see the same tree; but it is plain that what we immediately perceive, what is given in consciousness, does not remain the same as we move. Our blue patch of color grows larger and larger; it ceases to be blue and faint; at the last it has been replaced by an expanse of vivid green, and we see the tree just before us.
During our whole walk we have been seeing the tree. This appears to mean that we have been having a whole series of visual experiences, no two of which were just alike, and each of which was taken as a representative of the tree. Which of these representatives is most like the tree? Is the tree really a faint blue, or is it really a vivid green? Or is it of some intermediate color?
Probably most persons will be inclined to maintain that the tree only seems blue at a distance, but that it really is green, as it appears when one is close to it. In a sense, the statement is just; yet some of those who make it would be puzzled to tell by what right they pick out of the whole series of experiences, each of which represents the tree as seen from some particular position, one individual experience, which they claim not only