William of Ockham was a 14th century English Franciscan friar famous for not quite saying entia non sunt multiplicanda praeter necessitatem (‘entities must not be multiplied beyond necessity’). This is perhaps the most common formulation of what has become known as ‘Ockham’s razor’ or the ‘law of parsimony’. He did however say (ie write) numquam ponenda est pluralitas sine necessitate (‘plurality is never to be posited without necessity’) and frustra fit per plura quod potest fieri per pauciora (‘it is futile to do with more things that which can be done with fewer’) – which are pretty close.
So it is perhaps ironic that the Franciscan friar himself interpreted it as meaning that ‘no plurality should be assumed unless it can be proved by reason, or by experience, or by some infallible authority’ (emphasis added) – like the Bible & other Christian sources.
Five hundred or so years later another William applied another razor to the kind of belief which infallible authority thrives on. William Clifford’s 1877 essay The ethics of belief declared that it is wrong always, everywhere, and for anyone, to believe anything upon insufficient evidence. By ‘wrong’ Clifford clearly meant ‘morally wrong’.
He tells the story of a ship-owner who suspected his ship might not be seaworthy, but managed to overcome his doubts – not by having her overhauled and refitted, but by trusting in Providence. He let her sail and she sank in mid-ocean. Was he guilty of the death of the crew? Undoubtedly. He sincerely believed his ship was safe, but he had acquired his belief not by honestly earning it in patient investigation, but by stifling his doubts.
What if the ship had actually been sound? Clifford argues the ship-owner would have been just as guilty – not of manslaughter of course, but just as guilty of believing something he had no right to believe, because the origin of his belief was unsound. So he would have been just as guilty of endangering the lives of his crew.
Clifford also argues that guilt accrues not just from any action arising from an unjustified belief, but from the belief itself. In practice it is impossible for a belief to be entertained without having any effect in the world, if only because each unjustified belief makes it easier to believe the next one. Unjustified belief is insidiously corrupting:
Every time we let ourselves believe for unworthy reasons, we weaken our powers of self-control, of doubting, of judicially and fairly weighing evidence. We all suffer severely enough from the maintenance and support of false beliefs and the fatally wrong actions which they lead to, and the evil born when one such belief is entertained is great and wide. But a greater and wider evil arises when the credulous character is maintained and supported, when a habit of believing for unworthy reasons is fostered and made permanent. If I steal money from any person, there may be no harm done from the mere transfer of possession; he may not feel the loss, or it may prevent him from using the money badly. But I cannot help doing this great wrong towards Man, that I make myself dishonest. What hurts society is not that it should lose its property, but that it should become a den of thieves, for then it must cease to be society. This is why we ought not to do evil, that good may come; for at any rate this great evil has come, that we have done evil and are made wicked thereby. In like manner, if I let myself believe anything on insufficient evidence, there may be no great harm done by the mere belief; it may be true after all, or I may never have occasion to exhibit it in outward acts. But I cannot help doing this great wrong towards Man, that I make myself credulous. The danger to society is not merely that it should believe wrong things, though that is great enough; but that it should become credulous, and lose the habit of testing things and inquiring into them; for then it must sink back into savagery.
The harm which is done by credulity in a man is not confined to the fostering of a credulous character in others, and consequent support of false beliefs. Habitual want of care about what I believe leads to habitual want of care in others about the truth of what is told to me. Men speak the truth of one another when each reveres the truth in his own mind and in the other’s mind; but how shall my friend revere the truth in my mind when I myself am careless about it, when I believe things because I want to believe them, and because they are comforting and pleasant? … It may matter little to me, in my cloud-castle of sweet illusions and darling lies; but it matters much to Man that I have made my neighbours ready to deceive. The credulous man is father to the liar and the cheat; he lives in the bosom of this his family, and it is no marvel if he should become even as they are. So closely are our duties knit together, that whoso shall keep the whole law, and yet offend in one point, he is guilty of all.
He defends his thesis against a number of potential objections, clarifying when it is sound or unsound to believe something on someone else’s authority, and establishing principles for avoiding systematic scepticism for example about the future or the past. He sums up as follows:
We may believe what goes beyond our experience, only when it is inferred from that experience by the assumption that what we do not know is like what we know.
We may believe the statement of another person, when there is reasonable ground for supposing that he knows the matter of which he speaks, and that he is speaking the truth so far as he knows it.
It is wrong in all cases to believe on insufficient evidence; and where it is presumption to doubt and to investigate, there it is worse than presumption to believe.
It is worth considering why Clifford sees it as not just unsound or unwise to believe on insufficient evidence, but as morally wrong. There is a ‘sin’ which, depending on the context, could be one of commission or of omission. The ship-owner has either deliberately misled the crew into believing he had done everything he should have done to ensure the ship was seaworthy; or failed in a duty of care. In his position he should have been aware of the possible consequences of suppressing his doubts, including the false beliefs he could have created in people he was exposing to danger.
Perhaps the most celebrated attack on Clifford’s thinking came from yet another William – William James (1842-1910): psychologist, pragmatist philosopher, and brother to novelist Henry James. So it is to William the third that we now turn.
© Chris Lawrence 2008