One of the foundation pillars of modern atheism is Hume’s radical and, as many see it, devastating attack on religion. It is not so much the arguments themselves that have influenced people. Indeed, Hume vigorously attacks religion all through the Dialogues Concerning Natural Religion in the person of Philo, who is clearly voicing the opinions of Hume himself, yet ends the book with a seeming grudging acceptance of it, an uncharacteristic failure to draw logical conclusions that has puzzled his admirers ever since he wrote it. Nor, even, are people usually persuaded into atheism by his celebrated attack on causality. Nobody really thinks that it may not be the cue that is causing the billiard ball to move even though you can’t see it doing it, and I don’t suppose that Hume, who was a great player of billiards, did so either. Indeed, he begins his An Enquiry Into Human Understanding by telling us that he will apply the methods that Newton had so successfully applied to physics to philosophy, and Newton without causality is like water without wetness. No, what is important about Hume is that he made it possible to even think of a world that is not caused by God, or a human being who is not ensouled, or unknown factors underlying the causality of the world that are not themselves causal, or a completely materialistic explanation of nature. Before Hume it had not really been possible to have a Godless view of the world, for humanity was impregnated with religion, and in making it possible Hume greatly extended the territory of human freedom.
Hume would apply the rational methods Newton had used to philosophy, he will reach rational conclusions through gathering data, in this case facts about the human mind; by conducting experiments, in this case thought experiments as his subject is thought; and through strict and logical deductions from evidence. But the more you look into Hume’s philosophy the more irrational you find it to be, for his apparently rational arguments are never really more than rationalizations of irrationally assumed originating metaphors. He takes it for granted that we receive all our knowledge through our senses, inputs of data that he calls impressions. Ideas are copies of these impressions. Complex impressions, and their copies in complex ideas, are never more than aggregations of simple ones. There is no such thing as a whole tree, but only a collection of trunk and branches and leaves, which in their turn are aggregations of the atoms that compose them. But this is no argument, only bald assertion. He is already presuming an answer to a question that he has never asked and never does, although in fact this is the very first question he needs to pose, for it is the assumption that before all others, since it underlies everything else, you cannot make Once you simply assume that objects impress themselves materially on our senses as a signet ring leaves an impression in wax, to use Locke’s metaphor which underlies Hume’s, and assume that ideas are copies of impressions in the sense that a photocopier produces a material reproduction of the material it copies, as we might say, then you have already ruled out the possibility that a tree might be a whole tree. There is not even a possibility that its material parts are marshalled into a coherent order by an over-riding immaterial principle. Hume may be right. But he has not argued that he is in any way. He has merely made the conclusions he reaches inescapable through the constrictions of the language in which he presents them. It is like saying that a musical symphony is nothing but a collection of notes. Just look at that score. Can you see anything but notes? Well no. Thought so.
Few philosophical propositions have been more influential than Hume’s attack on the self, a line of argument that underlies the difficulty so many people have over belief in the soul. When I look into myself, he says, I see only sensations, experiences of hot and cold, pleasure and fear, I find no evidence of a self. This is like going out into the garden and saying ‘All I can see are flowers and trees and shrubs and stones, it just proves I’m not here.’ Once again thought has been usurped by metaphor. Hume assumes that knowing your self is the same kind of operation as feeling hungry. There is an unspoken, and within its own terms irrefutable, metaphor of opening a door and going from one room into another.
If there is a celebrated argument by Hume that has been even more influential than his attack on the soul it is his refutation of miracles. Suppose, he says, that a jury of twelve good men and true are asked to pass judgment on whether somebody has risen from the dead. On the credit side they would have every reason to think that the New Testament writers were reporting what they genuinely believed to have been the case. But have we ever seen anybody rise from the dead? Well no. But we do know of many cases of mistaken perception, hysterical delusion, mistakes over identity and grave robbery. On the balance of evidence they would have no option but to believe that this person did not rise from the dead. An unmiraculous explanation for apparent miracles will always be a more rational conclusion to draw, for however little evidence there may be for it, by definition there is no evidence for the miraculous explanation at all. But again, this is not the sensible argument that it appears to be, for it relies on an underlying and unspoken metaphor of the universe as law court. But the universe is not a law court. Science shows us ever more wondrously that it is a place of incredible wonders and mysteries that constantly outdistance our attempts to explain them. On Hume’s own argument of likelihood, a God taking human form and rising from the dead, unlikely as it might seem, is in so amazing a universe at least as likely, perhaps more so. The one thing of which we may be certain is that propositions about the ultimate truths of reality will not be the same kind of thing as the judgments that a jury of twelve men might make about a case of shoplifting in a supermarket in Basingstoke, a level of discourse to which Hume is constantly trying to reduce them.
Nevertheless, Hume is of great value to us all, for he frees us from certainty. If we can’t even be sure that one thing causes another, or that we are not the selves we presume ourselves to be, then of what can we be sure? He did, after all, turn out to be right about causality. Underlying the obviously causal operations of the cue causing the ball to move lie the non-causal , or perhaps hyper-causal, processes of quantum physics. Yet Newton was not wrong either. Within one particular metaphorical framework, the one we quotidianly inhabit, he was right. His laws of motion got a man to the moon and back. Everything we know to be right is at the same time not right within a larger framework, of which, because it is larger, we have only limited knowledge, and that always misunderstood because we inevitably interpret it within the terms of what we currently know. We all operate, as Hume himself did, within cages of assumed metaphor. You cannot play billiards without assuming that cues cause balls to move.
Paradoxically Hume made religious belief possible. Before him it was virtually impossible not to have religious certainty – although people like Hobbes had a kind of disgruntled go – for there was no language available in which to express, or even think, doubt. Yet it is of the essence of faith to put your emotional trust in what is intellectually uncertain. Otherwise you would not , could not, believe for you would know. Perhaps even more importantly he also frees atheists from the dogmas in which they too are so often imprisoned, although few of them see this. They generally think that religion has been exploded because religious myths have been replaced by scientific certainties. But Hume shows us that there is no certainty. Even Newton did not just get it wrong, but radically, foundationally wrong. Like Hume’s jury of twelve men we have to make the best judgments we can within the complexes of metaphorical assumption within which we find ourselves. So perhaps Hume’s final remarks about religion in A Dialogue are not so illogical after all. Perhaps in the end he felt that all we can say about religion is that it may or may not be true. We cannot speak with mathematical certainty but only make the kind of pragmatic judgments that men make in a law court. Atheism, like religion, may or may not be true. But we have to plump for one or the other.
We just have to be as honest as we can and make the best of the circumstances in which we find ourselves. Intellectually I find Hume less than wholly persuasive. But what philosopher ever was wholly persuasive, since the subject matter of philosophy is everything? Philosophy is not a logical but a moral enterprise, and this surely is why Hume is amongst the most admirable of philosophers. What words since Job have ever spoken so movingly and anguishedly of the horrors of the world, and so fiercely challenged the complacency that so often attends religious belief?
‘Look round this universe. What an immense profusion of beings, animated and organized, sensible and active! You admire this prodigious variety and fecundity. But inspect a little more narrowly these living existences, the only beings worth regarding. How hostile and destructive to each other! How insufficient all of them for their own happiness! How contemptible and odious to the spectator! The whole presents nothing but the spectacle of a blind nature, impregnated by a great vivifying principle, and pouring forth from her lap, without discernment and parental care, her maimed and abortive children.’
Yet, Boswell tells us, Hume was ‘as cheerful as a man may be’ on his deathbed. Boswell’s account moves me to tears. I salute you, David Hume, so honest a philosopher and so admirable a human being.