On Being Uncertain:
A Case for Scepticism
by Sean Gabb
I will write nothing yet again about the great issues of the day. I will instead respond to several of my readers who objected to my confession of scepticism in my last piece about ghosts. I am asked how I can be a sceptic when our knowledge of the world is based on such sure foundations. How can I deny the obvious, and so join myself to the nihilists whose own course of doubt ends in the various kinds of political correctness, and whose denial of reality in earlier generations cleared the way for the gulag and the holocaust?
My answer is that the probability of a belief is not determined by its alleged consequences. As for nihilism, I am not devoid of belief. I have strong beliefs, indeed, on just about every subject. I am a sceptic in the sense that I do not believe rational certainty to be possible in any of these subjects. In arguing this, I do not pretend to originality. Nor do I claim that this will be an academically useful essay. I am writing while sat on a railway train, far away from my books. If I draw on the thoughts of Plato, Lucretius, Cicero, Sextus Empiricus, Descartes, Berkeley and Hume, it is without consulting them on any point, and often without having read them for many years. I will use and conflate and alter the ideas of others as I see fit to argue my case. This being said, I will begin.
First, I take the existence of an external world. I perceive a stream of sensory impressions. I see shifting patterns of colours, and hear sounds, and feel heat and cold and soft and hard; and I have sensations of taste and smell. But I cannot know for sure if these impressions are in any sense related to an external reality independent of my perceiving it. I have had dreams in which I do not for a moment suppose any immediate connection between the things perceived and their existence outside my mind. It may be argued that the impressions of my waking life are different in both intensity and internal coherence from those when I am asleep. I disagree. I have had dreams quite as vivid and my waking experiences. As for continuity, I seldom notice any carrying over of memories between one dream and another. I recall them all afterwards as fragments. In each of them, though, I generally have the same awareness as I have now of a permanent state of affairs.
It is not inconceivable that I am now dreaming—or, to use the modern terminology, to say this does not imply any contradiction. Or I could be some vastly superior being—God, perhaps—who has grown bored with perfection, and like, the Thetans of Scientology, has created an imaginary universe in which to divert himself. Or, to connect myself for a moment with the popular culture, I could be imprisoned in a bottle and plugged into a computer that feeds me a stream of perceptions of a world that my gaolers destroyed a very long time ago, or that never existed in the first place. I have no means of knowing anything for sure about the world.
Even assuming that the world does exist, I cannot know that I perceive it as you do. What I see as blue, you may see as red. What you smell as a rose, I may smell as mown hay. The words we attach to impressions are conventional in their meaning, and all that matters is that we use them consistently. Just as when I see the first number written, I say “one” to myself, and a Frenchman says “un”, and a Slovak “jeden”, so the words attached to things may not describe the same impressions on all our minds. This may also apply to shapes and even ideas. I cannot tell.
Even assuming further, that the world exists and that we all perceive it in much the same way, we cannot be sure why it behaves as it does, or how long it will continue so to behave. It may be that the apparent connections between events that we call cause and effect are derived from a set of universal laws. Or it may be that nothing exists but atoms moving at random, and that these have temporarily come together into an appearance of stability vastly more unlikely than throwing a million double sixes at dice. Again, this is not inconceivable, and so it is possible. This conjunction may last for a long time to come, or it may end a moment from now—or it may continue, but with unexpected changes in the sequence of events. All our science is grounded on observed regularities, and no amount of clever reasoning from the laws thereby derived can strengthen this grounding. Just because the sun rose yesterday gives no rational certainty that it will rise tomorrow, or that it will rise in the east. We believe that it will rise, but cannot do more than believe.
In the second place, there are the truths of reflection. If I take thought, I seem to know that two and two make four and neither five nor three, and that the square of the side of a triangle opposite a right angle is equal to the sum of the square of the other two sides. But I cannot know these things for sure.
I cannot know them because I cannot know to what degree I exist. I can say with Descartes “I think, therefore I am”, which is an undisputable proposition. But it is undisputable only in the present moment that I conceive the idea. It gives me no surety that I shall exist a moment later, or that I existed a moment before. Again to connect myself with the popular culture, I might be a replicant, brought into being quite recently, but given apparently true recollection of events from before then. Or I might be the purchaser of an extended holiday from the Rekall Corporation—though if so, I shall want a refund when I wake. Yet again, none of these possibilities is inconceivable; and what can be conceived can be.
This being so, I cannot be sure of the truth of any complex reasoning. If I try to examine the theorem of Pythagoras, for example, the larger part of my reasoning is remembered from a time that may not have existed, and what I conclude in the present may rest on a delusion. Even if I have existed as long as I believe I have, I may be the victim of some force that systematically diverts my thinking from its logical course, so that I always reach a false conclusion. I once dreamed that I had found the internal angles of a triangle not to be equal to 180 degrees. I once dreamed, indeed, that I could see the music of Beethoven flowing through a plastic tube. On each occasion, I was filled with a sense of absolute conviction, though I cannot now say exactly how these things appeared—I recall my descriptions on waking, not the things described—I cannot be sure that what I conceive awake is not also deluded.
It goes without saying that all the trivial analytic truths alleged against scepticism are also to be doubted. The same object may well be able to exist in two places at the same time. When two things are equal to something else, they may not be equal to each other. Not all bachelors may be unmarried men.
So where does this leave us? Does it justify us in believing that nothing exists or that nothing matters? Does it mean that it is not wrong for me to murder my neighbour and rape his wife before sending her to be worked to death in a labour camp? Or that the world view of radical Islam is no worse than that of western liberalism? Or that all knowledge—not excepting the laws of motion—is socially constructed to serve some ideology of repression? I do not think so.
Faced with the apparent reality and consistency of things, I feel no choice but to believe in them—or perhaps I just choose to believe in them. I believe that you exist, and that the whole universe exists as I experience it or as it is persuasively explained to me. I also believe in the validity of clearly conceived ideas. I cannot know these things in the sense that a philosophical rationalist claims to know them, but I see no reason not to believe in them.
From this, it follows that, if we feel any benevolence for our fellow creatures, there are fairly obvious ways of adding to the common stock of happiness. People should be left, so far as possible in the given circumstances, to mind their own affairs. Given that we are left to mind ourselves, there is a large body of experience on which we can draw to minimise our chances of personal unhappiness or the hatred of others from which this often proceeds. We have fair reason to know what is the good life and how to achieve it. So long as it tastes good, does it matter if our dinner really and truly exists? So long as I love her, does it matter if my wife may vanish every time I look away from her?
Only when it is defined as an absolute and undeniable certainty does knowledge become a problem. It is no problem at all, so long as we rely on the evidence of our senses and judge this according to our common sense. That gives us all the knowledge of which we are capable, and all that we need for the improvement of ourselves and of the world around us.
There may be nothing more suited to making the world into a nightmare than an ideology that claims a rational certainty to its conclusions. When disagreement is seen as proof of imperfection or of malevolence, the call for persecution is never far behind. Above the metaphorical entrance to every good society that has ever existed has been inscribed the words “Nothing too much”.
I am a sceptic and a libertarian and a conservative; and these are connected views of the world. I do accept the need for occasional unpleasantness to others. I would send a man to prison for theft; and if I doubt the value of hanging a man for murder, I do believe in the right to shoot him if I catch him uninvited in my house at night. If I can be persuaded that it is for the defence of the community to which I belong, and that no unavoidably horrible consequences will follow, I accept the use of weapons of mass destruction. But I do all this in the belief that I may be wrong, and that I may one day regret all this, or be held up to universal infamy. I see tolerance as a virtue, and I welcome diversity of lifestyle. I think I know roughly what is best for people, but would never presume to impose it on them —unless to prevent them from interfering with the legitimate rights of others.
There—to the best of my ability, and as briefly as I can, I have made my case for scepticism. I only wish I could make a convert of Tony Blair. While nothing can undo the crimes he has already committed, I know as surely as I need to that the world would be a better place in future could it be spared more of his smug, murderous conviction.