Philosophical Studies · G. E. Moore
THE NATURE AND REALITY OF OBJECTS OF PERCEPTION
The theory, therefore, that nothing exists, except when it is perceived, is no objection (even if it be true) to the supposition that colours do exist. What objections are there to this supposition? All serious objections to it are, I think, of one type. They all rest upon the assumption that, if a certain kind of thing exists at a certain time in a certain place, certain other kinds of things cannot exist at the same time in the same place. They are all, that is to say, of the same type as Berkeley's argument: that, though the same body of water may _appear_ to be simultaneously both hot and cold (if one of the hands we plunge into it is warm and the other cold), yet the heat and the cold cannot both _really_ be in the same body at the same time. And it is worth noticing that anyone who uses this argument must admit that he understands what is meant by "really existing in a given place," and that he means by it something _other_ than "being perceived as in a given place." For the argument itself admits that _both_ the heat _and_ the cold _are_ really _perceived_ as being in the same place, and that there is no difficulty in supposing that they are so; whereas It urges that there _is_ a difficulty in supposing that they both _really exist_ in it.
Now there is one obvious defect in this type of argument, if designed to prove that _no_ sensible quality exists at any place where it is perceived as being--a defect, which Berkeley himself admits in his "Principles," though he omits to notice it where he repeats the argument in his "Hylas." Even if we assume that the heat and the cold cannot _both_ exist in the same place (and I admit that, in this case, the contrary assumption does seem repugnant to Common Sense), it does not follow that _neither_ exists there. That is to say this type of argument, even if we grant its initial assumption, will only entitle us to conclude that _some_ sensible qualities which we perceive as being in a certain place at a certain time, do not exist in that place at that time. And this conclusion, I am inclined to think, is true. In the case, for instance, of the so-called "images" which we perceive in a looking-glass, we may very readily admit that the colours and shapes which we perceive do _not_ exist at the places where they appear to be--namely at various distances behind the glass.
But yet, so far as I can see, we have no reason whatever for supposing that they do not, _except_ the assumption that our observations give us reason to believe that _other_ sensible qualities _do_ exist in those positions behind the glass; and the assumption that _where_ these _other_ sensible qualities do exist, those which we see in the glass do _not_ exist. I should, therefore, admit that _some_ sensible qualities which we perceive as being in certain places, do _not_ exist in those places, while still retaining my belief that others do. And _perhaps_ this explanation is the one which should also be adopted in the case of sensible qualities which appear to be at a great distance from us. When, for instance, (as we say), "we see the moon," _what_ we perceive (if the moon be full) is a round bright silver disc, of a small size, at a place very distant from us. Does that silver disc exist at that place? With what suppositions does the assumption that it _does_ conflict?
Only, so far as I can see, with the supposition that the place in question is _really_ occupied by a body such as science has taught us to suppose that the moon _really_ is--a spherical body immensely larger than objects, in comparison with which the silver disc which we perceive is small; _or else_ with the supposition that the place in question is really occupied by some part of our atmosphere, or some part of the medium which science supposes to exist between our atmosphere and the moon; _or else_ with the supposition that the place in question is really occupied by what we might see, if the moon were nearer to us by many thousands of miles. Unless we suppose that some other object _is_ in the place, in which the silver disc appears to be, and that this object is of a kind which cannot occupy the _same_ place which is occupied by a silver disc, we have no reason to suppose that the silver disc does _not_ really exist in the place where it appears to be. And, in this case, we _perhaps_ have reason for both suppositions and should therefore conclude that the silver disc, which we perceive, does not exist in any real place.
Part, therefore, of these objections to our theory may, I think, be met by admitting that _some_ of the ... sensible qualities which we perceive do not exist at the places where they appear to exist, though ethers do. But there is, I think, another class of cases, in which we may be justified in denying that two things which (it is asserted) cannot occupy the same space, really cannot. I will take an instance which is, I think, typical. When we look at a drop of blood with the naked eye, we perceive a small red spot, uniformly red all over. But when (as we say) we look at the _same_ object under a microscope of a certain power, I am informed that we see a much larger spot, of similar shape, indeed, but _not_ uniformly red--having, in fact, small red spots at different positions in a yellowish field. And if we were again to look at the _same_ object through a microscope of much higher power still, we might perceive yet a third different arrangement of colours. Is there any fatal objection to supposing that all _three_ appearances--the uniform red spot, the yellowish field with reddish spots in it, and the third, whatever that may be--do all really occupy the same real spatial area? I cannot see that there is. We are familiar with the idea that a given spatial area may contain parts which are invisible to us. And hence, I think it is quite conceivable that parts of a given area may be _really_ occupied by one colour, while the whole is _really_ occupied by another. And this, I think, is what we actually _do_ believe in many cases. At all events, we certainly believe that the area which appears to be occupied by one colour really is _the same area_ as that which appears to be occupied by another. And, unless we assume that the area, in both cases, really is the same, we can certainly have no reason to deny that each colour does really occupy the area which it appears to occupy.
For these reasons I think that the difficulties in the way of supposing that _some_ of the sensible qualities which we perceive as being in certain places, really exist in the places in which we perceive them to be, are not insuperable. I have indeed not done justice to these difficulties; but then, neither have I done justice to what is to be said on the other side. At all events, I think it is plain that we have no reason to assert, in any case whatever, that a perceived colour does _not_ really exist in the place where it is perceived as being, _unless_ we assume that that very same place really is occupied by something else_--either_ by some different sensible qualities _or_ by material objects such as physical science supposes to exist. But what reason can we give for such an assumption? I have tried to show that our own observations can give us none, _unless_ we assume that some of the sensible qualities, which we observe as occupying certain places, do really exist in those places.
And, if this is so, then we must admit that neither he who believes (with Reid) in the existence of other minds and of matter also, nor he who believes in the existence of other minds and denies that of matter, can have, in his own observations, the slightest reason either for his assertion or for his denial: we must admit that he can have no reason for either assertion or denial, except one which consists in the assumption of the existence or nonexistence of something which he does _not_ observe--something, therefore, of the very same kind as that for which he gives it as a reason. I am very unwilling to suppose that this is the case: I am very unwilling to suppose that he who believes that Sindbad the Sailor really saw what the "Arabian Nights" represent him as seeing, has just as good reason (so far as his own observation goes) for believing this as he who denies it has for denying it. Still this may be the case. We _must_, perhaps, be content to assume as certain that for which our observation gives no reason: to assume such propositions as that Sindbad did _not_ see a Roc, and that you _do_ hear my voice. But if it is said that these things are certain; then it also appears to me to be certain that the colours which I perceive do exist (_some_ of them) where I perceive them. The more I look at objects round me, the more I am unable to resist the conviction that what I see does exist, as truly and as really, as my perception of it The conviction is overwhelming. This being, then, the state of the case, I think I may at least plead that we have grounds for suspense of judgment as to whether what I see does _not_ really exist; grounds, too, for renewed enquiry, more careful than such enquiry has sometimes been in the past. [1] Not now in 1921.
Ideas discussed in this chapter
Text from Project Gutenberg, public domain in the United States.