Lighten up, Clifford

November 2006

Followup essay: "Evolution and the ethics of belief")

William K. Clifford, a 19th-century mathematician and occasional philosopher, is famous in some philosophical circles for declaring:

It is wrong, always, everywhere, and for anyone to believe anything upon insufficient evidence. (Clifford, The Ethics of Belief, 1877)

If this is true, then surely all have sinned. But should we think it is true? The question is not whether any of us is doxastically blameless. I take it as practically axiomatic that we all believe some things we should not believe. But is belief on insufficient evidence always ethically culpable? Clifford was writing within a generation of Darwin's publication of The Origin of Species. We have learned within our own generation enough about human origins and its implications for our understanding of human nature to conclude that his judgment was too harsh.

I have often criticized those who would judge people's character by their beliefs. It is not only religious fundamentalists who think that only evil people can disagree with some orthodoxy, though others may have different notions of what constitutes evil. Plenty of political partisans, too, suppose that anyone sympathetic to their ideological adversaries just has to be suffering from some ethical defect. History offers plenty of examples, all of them scary, of what can happen when a group of people decide that only bad people can disagree with them.

But it does not follow that it makes no difference, from an ethical perspective, what we believe or why we believe it. Even if, as I believe is the case, moral standards can never be applied to thoughts but only to actions, I think Clifford argues convincingly that beliefs can never be entirely divorced from behavior. Our behavior is irreducibly influenced by our beliefs, and so we have to think right in order to live right.

Some oversimplification is necessary to keep this essay to a manageable length, but we can say as a first approximation that a person's behavior is right or wrong depending on its consequences for other people. In order to correctly judge whether to do something or not, then, he must correctly anticipate its consequences. He must know, or have good reason to believe something about, whether other people will be or are likely to be hurt as a result of his behavior. In such a situation, indifference to the truth is equivalent to moral indifference. A sincere desire to act morally will necessarily entail a sincere desire to know the truth.

The problem, for those who would judge others by their beliefs, lies in assuming that a desire to know the truth implies an ability to discern it. This is a basic flaw in the thinking of fundamentalists of all kinds. They assume that we're all born with some kind of truth detector, and that virtuous people instinctively know how to use it. Evidence to the contrary, though, is overwhelming and incontrovertible. Evolution designed our brains for only one primary purpose, and that was survival. Our ancestors had to stay alive long enough to reproduce, and then long enough thereafter to ensure that their children reached reproductive age. No other consideration mattered. They could believe anything at all, true or false, just so long as it didn't kill them to act on those beliefs.

But it is also a fact that in an indefinitely large number of situations, a person's survival does depend on the ability to distinguish truth from falsehood. The truth will make you free, and there also are times when nothing else can keep you alive. And so, even though it was never their primary function, our brains had to have evolved at least some capacity for discerning truth and rejecting falsehoods. That capacity rarely if ever had to work perfectly, though. It had to work right just often enough to keep people from making too many fatal mistakes. And as long as the extinction of Homo sapiens was avoided, there were not too many mistakes. Nature endowed us with an ability to reason because sometimes our ancestors had to believe true things in order to survive. She did not endow us with infallible reason because our ancestors did not always have to believe true things in order to survive.

Since we are a social species, our ancestors' survival was usually more dependent on cooperation with each other than on getting the scientifically correct answers to whatever questions they had about anything. Some consensus, right or wrong, was usually indispensable. For every village or tribe saved from an ill-advised venture by a maverick genius who happened to be right, ten others could have perished because of a zealous dissident who destroyed the social cohesion necessary for his community's survival. Independent thinking can certainly be a good thing, but there is no free lunch. Independent thinking can also be very dangerous, and not only to the person doing it. Evolutionary pressure would have tended to discourage it, but not weeded it out entirely, since it does occasionally promote survival.

Patricia Churchland nicely summarized nature's primary considerations in developing our brains. Her comments appeared in a 1987 article in the Journal of Philosophy:

Boiled down to essentials, a nervous system enables the organism to succeed in the four F's: feeding, fleeing, fighting and reproducing. The principle chore of nervous systems is to get the body parts where they should be in order that the organism may survive. . . . Improvements in sensorimotor control confer an evolutionary advantage: a fancier style of representing is advantageous so long as it is geared to the organism's way of life and enhances the organism's chances of survival. Truth, whatever that is, definitely takes the hindmost.

Secondary considerations are not ipso facto irrelevant considerations, though. That we cannot reliably discern truth from falsehood does not mean we cannot do it at all, and it especially does not mean that we have no obligation to do try to do it. All it means is that we have to be very careful about judging those who fail to do it as well as we suppose that we ourselves are doing it.

Since Clifford's time, we have learned much about our minds that Clifford could not have known and thus may be excused for overlooking. There is still more that we don't know than that we do know, but we do know a lot more than anyone did in his day. We now have a good idea why we believe so many falsehoods and, more to the immediate point, why we practically cannot help believing them.

Let us imagine that Clifford's shipowner, instead of sending his ship on its fatal way, had instead inspected the vessel as he should have. Finding it unseaworthy, he refunds the passengers' fares and retires the ship from service. He then borrows a large sum of money to have another one built. While it is being built, the nation's economy goes sour through no fault of his. Many maritime entrepreneurs, himself included, go broke. He has no money to repay his creditors, nor any foreseeable prospect of getting enough. His financial misfortune does not abrogate his obligation to pay his debts. It matters nothing how the misfortune occurred or whether he did anything to bring it about. He owes his creditors some money, and it is wrong for him not to pay them that money. But he cannot pay it. He does not have the money and there is no honorable way for him to get it, and so we attach no blame to his failure to pay the debt. The obligation still exists, but we excuse his failure to meet it.

In an ideal world, the shipowner would have done something to guarantee his ability to repay the loan. In such a world, though, it likely would never be necessary for anybody ever to go into debt. Rational ethics should tell us how to live in the world as it is, not as we wish it were.

We are obliged to believe truths and disbelieve falsehoods, and we should desire to meet that obligation. In order to meet it with regard to empirical propositions, we should believe only on the basis of evidence. But we cannot always do that. People may be rightly faulted if they don't even try, but we should be loath to chastise those who try without success. That is not to say we never may chastise poor reasoning, but it is to say we should never forget the injunction about him who is without sin being privileged to cast the first stone.

Just what constitutes sufficient evidence, anyway? Clifford offers hardly a hint of his criteria but comments briefly on two sources: the pronouncements of authority and inference from experience.

In what cases, then, let us ask in the first place, is the testimony of a man unworthy of belief? . . . In order that we may have the right to accept his testimony as ground for believing what he says, we must have reasonable grounds for trusting his veracity, that he is really trying to speak the truth so far as he knows it; his knowledge, that he has had opportunities of knowing the truth about this matter; and his judgment, that he has made proper use of those opportunities in coming to the conclusion which he affirms.

Clifford first remarks on people's tendency to be "perfectly satisfied" with answers from anyone of good character: "He wouldn't lie" is supposed to imply "He must be telling the truth." But of course an honest person can be honestly mistaken. Assuming that an authority's character is not at issue, we may believe something on his say-so only if we have good reason to suppose that he knows whereof he speaks. "And," Clifford says, "there can be no grounds for supposing that a man knows that which we, without ceasing to be men, could not be supposed to verify," but I'm justified in believing him if, in principle, I could verify it, given sufficient motive and opportunity.

Thus, I justifiably believe that evolution is a fact because scientists have assured me there is overwhelming evidence for it, and I could check that evidence myself if I were so inclined and had the resources to track it all down. What's more, I have read reports by people who were indeed so inclined, did have the resources, and did track some of it down. What's still more, I can read the literature of evolution's detractors and see that they failed to provide any contrary evidence or in any other way discredit the scientific consensus. On the other hand, practically every utterance ever attributed to divine revelation has been either of two kinds. Either it is by nature unverifiable or it has failed to be verified. Therefore, I am not justified in believing something just because I read it in a book that someone tells me was written under divine inspiration. If a particular assertion in the book can be verified and has been verified, then I should believe it, but not until then.

That certainly works for me. I managed to figure it out before I ever heard of William Clifford. But what should be my opinion of those who have not figured it out? I can certainly be of the opinion that they are mistaken, but should I be of the opinion that they are morally wrong?

I think that most people who believe on insufficient evidence are like the bankrupt shipowner. They have an obligation but are unable to fulfill it and therefore should not be censured. Most people, whatever they believe, think they have all the evidence anyone should need (which in some cases is none at all), and there is no way they are obliged to take anyone's word for it that they should think differently. The analogy fails at the point where the shipowner acknowledges his indebtedness while the believer thinks he is free of debt, but the believer is no more responsible for that mistake than the shipowner is responsible for his bankruptcy.

We are morally accountable for our behavior because we do something or refrain from doing it by an act of will. Whether I steal your money or not depends solely on whether I decide to steal it. It is a choice I can make. I cannot choose to repay a debt if I have no money. Neither can I choose whether I will be a Christian. I can choose whether to act like one and talk like one, but I cannot think like one by a mere act of will. And neither can a Christian stop thinking like a Christian by a mere act of will.

(This argument obviously assumes certain things about the nature and reality of free will. A discussion of the ethical implications of the various forms of determinism must be deferred for now.)

What I can do by an act of will is investigate whether a particular belief I hold is justified by sufficient evidence. This involves what Richard Swinburne calls diachronic justification, in contrast to synchronic justification.

Theories of justification that analyse what it is for a belief to constitute a justified response to the situation in which the believer finds herself at a given time, I shall call theories of synchronic justification. I contrast them with theories . . . of what it is for a synchronically justified belief to be based on adequate investigation over time, which I shall call theories of diachronic justification. Writers who advocate a theory of justification often do not say of which kind their theory is, and one needs to read their detailed exposition in order to see what is intended, and sometimes there is some doubt. But I think that it is right to construe most proposed theories as theories of synchronic justification. (Swinburne, Epistemic Justification, 2001)

What Clifford appeared to be arguing was that Swinburne's distinction is never morally relevant — that you had better, at any given moment, have all the evidence it takes to justify everything you believe. That is not something that human beings are capable of, though. We could not function if we tried to do it. It is as Paul told his Christian readers about the Mosaic law: It is just too much to ask of anyone that they be perfectly compliant with it. It is just not right to censure anyone for failing to do what they cannot do.

But we can be censured for indifference. If we are told by someone with any credibility, "You don't have enough evidence for your belief," the proper response is not, "It doesn't matter. It's my belief, and I have a right to it." The proper response is, "We'll see about that," followed by an investigation of the evidence conducted as thoroughly and impartially as one can conduct the investigation — commensurate with the moral importance of the belief.

It is not true, as Clifford seemed to suggest, that our every belief should be treated as if people's lives depended on its being correct. Of course it is theoretically possible that someone could get killed if I am mistaken in believing that Interstate 5 will be the best route for me to take when driving from San Bernardino to San Francisco next week. That contingency is too unlikely, though, to justify my treating it as a matter of life and death. I do not need to investigate the alternatives as thoroughly as Clifford's shipowner was obliged to examine his evidence for thinking his ship was seaworthy. (Obviously, though, I am similarly obliged to justify my belief that my vehicle's brakes and other safety equipment are in good condition.)

On other words, our epistemic obligations depend to a great extent on the consequences of our being wrong. Life is short, and we don't have the time or resources to check all our beliefs against the facts, and so we are justified, as Clifford himself concedes, in taking certain short cuts. It is, for example, morally OK for me to trust an authority, provided only that he or she really is an authority on the matter in question. Now, I am responsible for ascertaining whether he or she really is one, but how hard to I have to work at that task? Must I check out the curriculum vitae of every author of every book I read, or am I morally safe if I take the word of a trusted friend who assures me, "This person knows what they're talking about"? Again, I think it depends on, among other things, the consequences of my being mistaken.

What if I believe it would be a harmless error but am wrong about that? How thoroughly should I investigate the consequences of a particular belief? And what if I'm relying on an authority to answer that question? That regress has to stop somewhere, and I'm the only one who can decide where to stop it. I have no good reason to just take Clifford's word for it, or anybody else's, if they say I haven't done enough investigating. As soon as I do that, I'm handing my responsibilities off on someone else, and even if I want to do that, Clifford or anyone else has no right to take that responsibility.

Most adherents of the world's major religions have accepted the notion that love of God does not imply devotion to any sectarian creed. Christians for instance can, and many do, believe that a person can sincerely love God without believing that Jesus was his only begotten son. Secularists should be similarly tolerant about doxastic diversity. People can love the truth without knowing it or even knowing how to properly find it. If a Christian thinks he has plenty of evidence for Jesus' having risen from the dead, then I can certainly think he is mistaken, but I cannot think he is morally deficient unless he proves that he has no genuine concern about any evidence. If he will admit, "Even if I had no evidence at all, I would still believe in the resurrection," then he has an ethical problem. Absent such an admission or equivalent conduct, I should give him the benefit of doubt.

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