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G.E. Moore’s Hands

Roger Caldwell takes a sceptical look at scepticism.

Some questions asked by philosophers might occur to anyone. Few of us have not been visited at one time or other by such basic queries as those asked in ethics (What is the best life? What is it to be good?); in political philosophy (What is the best form of government?); or even in the philosophy of science (How can we know if a scientific theory is true?).

GE Moore
G.E. Moore, including one of his hands

But when philosophers deny, or challenge us to prove, the existence of time, or motion, or other minds, or even of an external world, there is an evident parting of the ways between philosophy and common sense. We are being urged to reconsider things we have taken for granted all our lives, and the temptation is to respond with not reasoned argument but with demonstrations of the absurdity of the challenge. Thus in the ancient world, Diogenes the Cynic responded to a discussion of Zeno’s argument against the possibility of motion simply by getting up and walking about the room. In the eighteenth century, Samuel Johnson, confronted by Berkeley’s contention that nothing exists but ideas and minds, kicked a stone and declared “I refute him thus!” In the twentieth century G.E. Moore, to disprove the contention of the idealists that there is no external world, held up first one hand and then the other thereby demonstrating, as he claimed, that here were at least two objects that were evidently part of the external world.

This sort of response to the sceptic is in essence a refusal to acknowledge the intellectual seriousness of the challenge or the sincerity of the sceptic himself. There is a sense of unreality about the sceptic’s challenge, as if the doubt he expresses is one that no one could really accept. In Iris Murdoch’s pithy formulation, “McTaggart says there is no such thing as time, Moore says he has just had his breakfast.” Or the Greek sceptics, recognising that we were sometimes deluded by our perceptions, went on to argue that we could never be sure that any given perception was true to reality, thus making certainty impossible. Aristotle, a philosopher who had a robust sense of reality, had a short way with them. In his Metaphysics he declares that “nobody really is in these circumstances, neither any of those who advance this argument nor anybody else.” But not even the sceptics would claim there can be such thing as living according to the tenets of scepticism.

The Possibility of Scepticism

Parmenides aside, the Greeks never developed a comprehensive external-world scepticism: they didn’t move from the position that any of my perceptions could be delusive at any time to the position that all of them could be at all times. That step was famously taken in modern times by René Descartes in his Meditations (1642). There he asks how he can know that God “has not brought it about that there is no earth, no sky, no extended thing, no size, no place, while at the same time ensuring that all these things appear to me to exist just as they do now?”

The contemporary version of Descartes’ thought experiment is the brain-in-a-vat hypothesis suggested by Gilbert Harman and famously responded to by Hilary Putnam. It says that, far from having bodies and moving about in space, we are brains in vats, hooked up to a sophisticated computer perfectly simulating our experiences of a world. This idea was again advanced purely for the purpose of argument; of course Harman did not actually believe that he was a brain in a vat. But for the sceptic, that’s not the point. No one sane believes that he’s really a robot; but it’s nonetheless possible that he is. Most of us think we have free will, but it’s possible we don’t. And as long as it is possible that we are brains in vats, we cannot know for certain that we are not.

Reasons To Be Sceptical?

Nonetheless, there is an obvious asymmetry here. Given the possibility of physical determinism, there are good reasons why we may wish to argue the issue of free will; there are no reasons whatever for seriously considering that we are brains in vats. If it’s on low-lying ground and there’s a river nearby, we may wish to insure our house against flooding; but we have no reason to try to insure it against all possibilities of damage, especially very far-fetched ones such as it being demolished by a flying saucer. Philosophers often give us logical possibilities, when all that we require are realistic possibilities.

Quine in his Two Dogmas of Empiricism (1951) argues that no scientific statement is immune from revision, in that any alternative statement can come to be held true “if we make drastic enough adjustments elsewhere in the system.” Our scientific world-picture is admittedly scarcely set in stone. Any of our scientific theories in principle may be jettisoned. However, it is vanishingly unlikely that what we think of as bedrock science is going to be overturned. In principle it is possible that we are radically mistaken about the chemical composition of water, or the properties of hydrogen and oxygen, for example; but no one is going to lose much sleep over the matter. Analogously, if she is to be worthy of an answer, what the sceptic needs is to raise in us living doubts, and she can’t do this if all she is offering are mere logical possibilities. Moreover, if we are to take seriously any accounts of the world that rival those we currently possess, their proponents must recognise that we start from the assumption that the best explanation is likely to be the simplest one that fits the known facts. It is pertinent to ask of any sceptical alternative if it is more cogent or concise, or offers fewer improbabilities than the standard realist picture of an external world experienced via our senses and existing independently of human thought. One may doubt the existence of space, but nonetheless, the simplest reason for its taking us longer to walk from A to B than from A to C is that the distance in the latter case is less than that in the former – and we can after all measure them to confirm this. Or one may doubt the existence of time, but the facts that we all get older, that yesterday preceded today, and that we have memories of the past, are better accommodated by assuming the reality of time than devising obscure hypotheses to explain away our experience of its passing.

Scepticism versus Common Sense

It is widely recognised that to embrace the sceptical position is to go against common sense. Indeed, during the Scottish Enlightenment there was a whole school of philosophy that went under the name ‘Common Sense’. Thomas Reid’s An Inquiry into the Human Mind on the Principles of Common Sense appeared in 1764. In it he declares that “In this unequal contest betwixt Common Sense and Philosophy, the latter will always come off both with dishonour and loss.” G.E. Moore, much influenced by Reid, echoes this commendation of common sense, and if not all of his writings can nowadays be thought to show it, his most famous papers against scepticism clearly do. In ‘A Defence of Common Sense’ (1925) he defends the position that we can know empirical truths with certainty. In ‘Proof of an External World’ (1939), he argues that we already know that there is an external world, that it was never in doubt, nor can we seriously put it in question, since there being an external world is a condition of our existence as human beings.

Hands © Venantius J. Pinto 2018
To see more art, please visit https://www.flickr.com/photos/venantius/albums

Do Moore’s Hands Miss The Point?

Moore’s hands have become iconic in the extensive contemporary literature on scepticism. Whether one is a contextualist, a reliabilist, a coherentist, or a referentialist, or takes some other stance concerning our knowledge of the external world, one will have something to say about Moore’s hands. This is remarkable, not least because at first sight Moore spectacularly misses the point. For it is not as if by holding up his hands Moore is making the sceptic aware of something he had somehow overlooked. The sceptic also has hands, and uses them in the same way that Moore does, including to point at things. As Ludwig Wittgenstein puts it in a text which was partly written in response to Moore, On Certainty (1949): “Doubting the external world is not doubt of the existence of something within that world.” In other words, the sceptic’s challenge can’t be falsified by an empirical discovery about the world, because it is the world itself that has been put into question. All our experience of the world remains as before. What is at issue is how we interpret it.

But is anything really at issue here other than a matter of words? In effect Moore is turning the challenge back on the sceptic. After all, the sceptic lives his life in the same way Moore does: he may doubt the existence of time, but he still consults his watch. He may doubt the possibility of motion, but if late, still runs for a bus. If hands, and everything else, operate in the same way in the sceptic’s world as in that of his opponent, where does the difference lie?

There’s a parallel here with Pyrrhonian scepticism in the ancient world. Sextus Empiricus (c.160-210), for instance, tells us that whereas the dogmatist – or as we would call him, the realist– moves from perception, feeling that the bathwater is hot, to the judgement that the bathwater is indeed hot, the sceptic in effect stays at the perceptual level and suspends judgement as to whether the water is in itself hot or cold (and indeed, one presumes, whether what appears to be water is indeed water). Again, one might expect there to be a resultant difference of behaviour from these radically different positions, but there isn’t: the sceptic, suspending his belief, nonetheless enjoys his bath in exactly the same way as his dogmatist opponent.

Against scepticism, Greek and Roman Stoics employed what they called ‘the argument from inaction’, saying that if one never made a judgement, it would be impossible to do anything, given that actions require prior judgements. The sceptic does perform actions, therefore his claim to suspension of judgement must be a false one. Thomas Reid, more than two millennia later, makes the same point: of the man who “pretends to be a sceptic with regard to the informations of sense, and prudently keeps out of harm’s way as other men do, he must excuse my suspicion, that he either acts the hypocrite, or imposes upon himself.” The sceptic’s doubt is always one that exists only in principle – it never comes to be actualised.

Unavoidable Knowledge?

For Moore, as for Reid, the sceptic attempts to make us doubt things it is impossible to doubt. We are unable to doubt that we are human beings, that the Earth existed before we were born, or even that London is a city in England. Moore declares that “I can know things which I cannot prove”; Wittgenstein tells us that “we know this is a hand because we know English.” We were born into a world in which some matters cannot be subject to revision. Wittgenstein speaks of ‘hinge propositions’, on which everything else in our world depends but which are not so much known as presupposed. Without them a world common to us all could not exist. So much surely is common sense.

Or is it? Wittgenstein was also aware, in a way that Moore perhaps was not, that what is common sense in one time and place is not so in another. It was once common sense (and in some parts of the world it still is) to believe that the Earth is the centre of the universe; that the universe was created by God; that we should guard against witchcraft; that women are inferior to men, and so on. But to acknowledge the malleability of common sense should not be seen as a concession to the sceptic, for if common sense is imperfect it is scarcely the sceptic to whom we would go to remedy its deficiencies. Science, of course, does go against common sense, and does so with success. There is nothing commonsensical about our being composed of atoms, or the theory of evolution, or, least of all, the world of quantum physics. So why should we believe the scientist and not the sceptic? We do so because science is based on evidence and testing, and because its findings can be confirmed or disconfirmed. That’s why it is an ever-growing body of knowledge, much of which can be used to practical effect. By contrast, the sceptic offers us no such discoveries. He relies only on the power of reason: his only experiments are thought-experiments, his only proofs (if any) are those of logic. Using these means, there are only two ways the sceptic can shake our realist preconceptions: he can cause us to doubt the truth of our perceptions, or he can try to show that the categories in which those perceptions are embedded are self-contradictory. Both are difficult tasks. As we have seen, in the first case, all the sceptic can offer us is the theoretical possibility that our senses comprehensively deceive us; but he gives us no good reason to suppose that they do. In the second case, ingenious uses of reason to dispose of such pervasive illusions as those of motion, matter, and time, face an uphill struggle against what appear to be self-evident truths. Zeno’s paradoxes attempting to prove the impossibility of motion, such as that of ‘Achilles and the Tortoise’, for a long time seemed unanswerable through reasoned argument: nonetheless, few, if any, were convinced by them. Moore’s contemporary at Cambridge, McTaggart, attempted to disprove the passing of time; but few then or since have found his arguments persuasive. In the absence of reasons to dislodge our obstinate grip on what we think of as reality, or of any compelling arguments that show our basic concepts are immured in impossibilities, it is hard to see why we should be troubled by the sceptic.

Immanuel Kant thought it a scandal in philosophy that there existed no proof of the external world. But is it? If no one has offered sound incontrovertible reasons to disbelieve in it – to disbelieve in what has always been part of common sense in all times and places – surely such a proof would serve no practical purpose anyway.. The scandal would instead be that so many philosophers have spent so much time in trying to counter the sceptical challenge, when that challenge is nothing more than a chimera.

© Roger Caldwell 2018

Roger Caldwell is a writer living in Essex. His collection of poetry, Setting Out for the Mad Islands, is published by Shoestring Press.

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