The Rejection of Skepticism

Transcription

1 1 The Rejection of Skepticism Abstract There is a widespread belief among contemporary philosophers that skeptical hypotheses such as that we are dreaming, or victims of an evil demon, or brains in a vat cannot sensibly be ruled out as false. This belief is ill founded. In fact, it is based on a failure to see that skeptical arguments beg the question. Such arguments assume that reality is not an immediate given of experience in order to prove that reality is not an immediate given of experience. This point is explained and justified in detail. Conversely, however, the realist would beg the question in the opposite way if he tried to prove realism. The conclusion we should reach is that skepticism and realism are problems of immediacy and not of proof They face us with a choice between alternatives that are not only radically different but also pretty much impregnable and irrelevant to each other. This choice is not arbitrary, for there are grounds to determine it. But the grounds are the immediate evidence and not the arguments.

2 2 The Rejection of Skepticism There is a widespread belief among contemporary philosophers that skepticism about the external world, even if it is highly improbable, cannot be ruled out as clearly or certainly false. The reason commonly given is that our awareness or experience of the world is not such as to exclude the possibility that we may really be dreaming or brains in a vat or deceived by some evil genius. If any one of these skeptical scenarios obtained, so we are told, we would not be able to tell that it did obtain, for our experiences would remain exactly the same and there would be no discernible difference between skeptical experiences and real experiences But there is a crucial assumption lying behind this claim, an assumption that those who make the claim neither argue for nor, in most cases, even notice. The skeptical scenarios in question are asking us to suppose that the reality of real experience is not itself a given of that experience. If reality were such a given, the scenarios would at once be shown to be false because we would be able to tell the reality of experience directly from experience itself. So if we are going to be thrown into skeptical doubt by these scenarios, we have to assume in advance that reality is not a given of experience. Nevertheless, these scenarios are expecting us to assume that other things are givens of experience, such as impressions of color, of shape, of size, and so forth. The skeptic is not asking us to doubt that we are having experiences at all: he is only asking us to doubt that the experiences we are having are of a real world. For while we are supposed to allow that a demon, say, or a mad scientist could give us impressions of reality without giving us reality, we are not supposed to allow that such a demon or scientist could give

3 3 us impressions of reality without giving us impressions of reality. The skeptic grants, then, that some things are immediate givens. The question we must ask is which things. And here it is crucial to note that the skeptic gives, and can give, no argument that these givens could be impressions only and not real things. All he can ever do is assume this. In fact, arguments based on skeptical hypotheses always assume, and never prove, that real things are not indubitable givens. This is apt to be missed since these arguments do purport to prove that we cannot know we are not dreaming and so forth. But this turns out to be an illusion. The question, after all, is simply whether the givens of experience are real things or indistinguishable from images of real things. If the skeptic says that they are the latter because we could now be dreaming (or deceived or brains in a vat), he has begged the question. We could only now be dreaming or so forth if the givens of experience could now not be real things. For if in fact they were real things, then we would clearly not be dreaming. In other words, the skeptic cannot use the possibility that we could now be dreaming to prove that our experience could now not be of real things, since this latter supposition is needed to make the dreaming hypothesis possible in the first place. lf the skeptic tries to reply that since I have, in the case of dreams at any rate, been deceived into thinking that what I experience is real when it is not, the same thing could, for all I know, be happening now, he would just beg the question all over again. The same thing could only be happening now if what I am experiencing now might not be real. For if it is real, and immediately given as such, I am clearly not being deceived into thinking it is real when it is not. What is going on in these skeptical arguments, and what gives them, I think, much of their plausibility, or much of their appearance of being arguments, is an

4 4 equivocation over the word possible. There is a sense in which it is possible that we could now be dreaming or deceived or brains in a vat, namely in the sense that none of these hypotheses is self-contradictory. Things could conceivably be such that we were now dreaming and so forth. Let us call this sense of possibility notional possibility. But there is another sense of possibility in which we could now be said to be dreaming, namely the sense in which it is not contrary to fact that we are now dreaming. Let us call this sense of possibility real possibility. To make the point clearer, take another example. As I write this I am sitting down. But it is possible, in the sense that it is not selfcontradictory, that I could be standing up. On the other hand, it is impossible, in the sense that it is contrary to fact, that I could now be standing up. For if, as a matter of fact, I am now sitting down I cannot now be standing up. I cannot do both at the same time. So it is with dreaming or being deceived or a brain in a vat. These hypotheses could be true in the sense that, as such or in respect of notional possibility, they involve no self-contradiction. But they could not now be true if, as a matter of fact or in respect of real possibility, I am now experiencing real things. It is through sliding from one sense of possibility to the other that the skeptical arguments look plausible. For if the skeptic is to make me doubt my experiences, he must show that his skeptical hypotheses are really possible. But his hypotheses are not true in that sense, or not obviously and incontrovertibly so. They are only thus true in the other and notional sense. He equivocates, then, if he proceeds from hypotheses or premises taken in one sense, that of notional possibility, to a conclusion that he wants taken in the other sense, that of real possibility. So, if he is to avoid this equivocation, he must, from the start, take his hypotheses in the sense of real possibility. He must, that is, show that

5 5 these hypotheses are not contrary to fact, or that I do not know that they are contrary to fact. And to do this, he must in turn show that my experiences are not immediately of real things. But, as I have already remarked, he cannot do this by means of his skeptical hypotheses since to do so would beg the question. These hypotheses need the supposition that my experiences are not immediately of real things in order to be really possible, as opposed to notionally possible, in the first place. Of course it is also true to be fair to the skeptic that if he is guilty of sophistry in trying to prove skepticism, I would be equally guilty of sophistry if I were to try to prove realism. For I could do this only, say, if I could take as premise that we are not now dreaming or deceived or brains in a vat, and I could only do this in turn (barring recourse to Descartes God) if my experiences were immediately of real things such that I knew that they were not dreams or deceptions or brain stimuli. That is to say, I could only prove that my experiences were immediately of real things if I first assumed that they were immediately of real things. The upshot of all this is that the problem of skepticism versus realism is not such as to be solvable by way of proof or argument. It has to be solved, if it can be solved, without appeal to proof. But this is already a considerable advance. It means we need pay no further attention, contrary to prevalent philosophical opinion, to skeptical or counterskeptical arguments. What we must do instead is focus our attention on what it is we directly and immediately perceive. Skepticism and realism are problems of immediacy and not of proof. The question we have to ask ourselves is whether what we are now immediately experiencing could just be images (possibly of real things or possibly not), or whether it is the real things themselves. But the only way to answer this question is

6 6 directly to consider experience. For what experience is immediately of must be evident from experience or not at all. Suppose, then, that, after due consideration, I say my experience is immediately of real things and you say that yours is not. Is my statement thrown into doubt by yours or yours by mine? Clearly neither. For if I find reality an immediate given then that is what there is and I am clearly a real thing existing among real things. If you do not then you are not (or it is not certain that you are). We will be living, in effect, in different worlds. For when I look at you, I will see a real body existing in a real world (for that is what I immediately experience). Consequently I can say about you, or this body standing before me, that the words coming from its mouth to the effect that it is not experiencing real things, or not directly, but what might be images or the like, are just false. For here it is, a real body with real eyes and ears and nose and hands, surrounded by real things and not images, and for it to say otherwise is for it to be in error if not also in bad faith. Conversely you, when you look at me, can be sure only of seeing an image or a combination of images, and the fact that associated with this image there is an audible impression to the effect that it is not an image but a real thing experiencing real things establishes, if it establishes anything, just a certain confusion among the images floating about in your mind. You certainly cannot say that I am lying or deceiving myself since, for all you know, I do not exist but am just an image beyond which there is or may be nothing. Here then is where, it seems to me, skeptical hypotheses end up: not with skepticism, as many philosophers have thought, but with a choice between alternatives that are not only radically different but also pretty much impregnable and irrelevant to

7 7 each other. This choice is, to be sure, not arbitrary, for it is to be decided by the evidence, the evidence of what is immediately given. But arguments, whether skeptical or otherwise, will not help. They may, perhaps, push one into deeper reflection about what one s experience is actually like. But they cannot, except sophistically, decide the issue.