An Introduction to Philosophy

ONS AND

with eyes closed, I can imagine it. I lay my hand on it and feel it; I can, without laying my hand on it, imagine that I feel it. I raise my

erence of which we are all somehow conscious, for we unhesitatingly dis

t is only imaginary. The horse that I imagine seems to have four legs, like a horse perceived. As I call it before my mind, it seems as large as the real horse. Neither the color,

e. One difference that roughly marks out the two classes of experiences from one another is that,

le doubt whether I feel a sensation or do not; but when he touches my back very lightly, I may easily be in doubt, and may ask myself in perplexity whether I have really been touched or whether I have merely imagined it. A

in the extreme. Others imagine things vividly, and can describe what is present only to the imagination almost as though it were something seen. Finally,

ction, that we do not actually make it our ultimate test. We may be quite willing to admit that faint sensations may come to be confused with what is imagined, with "ideas," but we

I know that I perceive the desk before me; and how do I know that, s

ain setting. That is to say, the desk seen must be in a certain relation to my body, and this body, as I know it, also consists of experience

t is when I recede from it. But how can I know that I am near the desk or far from it? What do these expressions mean? Their full meaning will become clearer in the next c

; "I see my desk," no matter how vivid the image of the object. Those who believe in "second sight" sometimes talk of seeing things not in this setting, but the very name they give to the supposed experience indicates that there is something abnormal about it. No one thinks it remarkable that I see the desk before which I perceive myself to b

mplete, though it may not, at first, seem so. Thus the unreal object which seems to be seen may be found to be a thing that cannot be touched. Or, when one has attained to a relatively complete knowledge of the system of experiences recognized as sensory, one may make use of ro

her for it. We need only reflect, and ask ourselves how we know that, in a given case, we are seeing or hearing or touching something, and are not merely imagining i

ement of this same criterion. It is important to him to distinguish between what is given in sensation and what is furnished by

which is common to us all. A real hand is one which we see with the eyes open, and which we touch with the other hand. If our experiences of our own body had not the setting which marks all sensory experiences, we could never say: I p

ot, we may call the experience imaginary. If there were such a reality as this, it would do us little good, for since it is not supposed to be perceived directly, we should have to depend upon the sensations to prove the presence of the reality, and could not turn to the reality and ask it whethe

riences. In the next chapter we shall see in what senses the word "reality" may properly

s willing to admit that the table in the next room, of which he is merely thinking, is known at one remove, so to speak. But this desk here befor

external world is known as directly as it is possible for the external world to be known, and that one can get no more of it than is presented in sensation. If a sense

May it not be, if we really are shut up to the circle of our experiences, that the physical things, which we have been accustomed to look upon as non-mental, are nothing more than complexes of sensations? Granted that there s

tence must be regarded as psychical existence. Their doctrine we shall consider later (sections 49

e to exist when he no longer has sensations. Moreover, he believes that things do not always appear to his senses as they really are. If we tell him that his sensations are the things, it shocks his common sense. He answers: Do

But it is clear that he feels strongly that the man who would identify them is obliterating a distinction to which his experience testifies unequi

e right, and can be shown to be in the right. "Things" are not groups of sen

e in the grate. I am experiencing sensations, and am not busied merely with an imaginary fire. But may m

ppose that the fire has been annihilated? No. We say, I

ore. Does any one suppose that my turning my head has done anything to the fire? We

sufficient distance, I know that the fire would appear to me smaller and less bright. Could I get far enough away to make it seem the faintest

blazes up, turns red, and finally falls together, a little mass of gray ashes. Shall I describe this by saying that my sensations have chan

e house changes as I advance. But, at a given instant, changes of a different sort make their appearance. Smoke arises, and flames burst from the roof. Now I have no hesitation in saying that

gard it as a mere seeming. I count on the clock's going when I no longer look upon its face. It would be absurd to hold that the distinction is a mere blunder, and has no foundation in our experience. The r?le it plays is too im

tions; but even he distinguishes between the sensations which he is studying and the material things to which he relates them, such as brains and sense-organs. And those who cultivate the physical sci

othing of all this appears in their books. What they are concerned with is things and their changes, and they do not consider such matters as these as falling within their province. If a botanist could not distinguish between the chan

things presented in our experience only as we have sensations? what is it to perceive a thing? is it not to have sensations? how, then, can we distinguish between sensations and thi

the external world comes to seem to us to be not really a something contrasted with the mental, but a part of the mental world. We accord to it the attributes of the latter, and rob it of those distinguishing attributes which belong to it by right.

fire in my study. As I stand and look at it, what shall I call the red glow whic

er the one or the other, according t

behind our backs. If we confine our attention to the bit of experience itself, we have no means of determining whether it is sensory or imaginary. Only its setting can decide that point. Here, we have come to another distinction of much the s

nsations. Why was this? Because it was observed to depend upon changes in the relations of my body, my senses (a certain group of experiences), to the bit of experience I call the fire. Ano

k over the matter and see what the unlearned and the learned are doing at every moment. Sometimes they are noticing that experiences change as they turn t

as we have seen, the man of science can study without troubling himself to consider sensations at all. This system is the external world—the external world as known or as knowable,

n of sense. They should never be confused with qualities of things, which are experiences in a different

please, describe them as complexes of qualities. And we may not say that the "t

es the material world, and the subjective order, the order of things mental, to which belong sensations and "ideas." That is "outside" which belongs to the objec

When men fall into the error of talking in this way, what they do is to keep the external world and gain the distinction, and at the same time to deny the existence of the world which has furnished

order is known as directly as is the subjective order. Both are orders of experiences; they are open to observation,

a solution. We all believe that material things exist when we no longer perceive th

ying that the comet, which has sailed away through space, exists, and will return. The ge

ces? and can there be such a thing as an experience that is not experienced by s

s in the past. Bishop Berkeley (1684-1753) said, "To exist is to b

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

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 n

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

ing 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 mu

icate the phenomena which have a place in the objec

rceive 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 pract

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 cons

te, 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

chapter at the close of t