Jeff has a post up about Carl Sagan's statement "Better by far to embrace the hard truth than a reassuring fable." As a counterexample, he offers the fact that the story of Jesus would be valuable in inspiring ethical conduct even if it were proven scientifically that Jesus never lived.

But I don't think that the example Jeff is using does what he wants it to do. It seems quite possible to extract the benefits of Jesus as an ethical model without believing that he was a historically real person -- much as we can be inspired to lead a better life by the example of the tortoise who outran the hare, or by Gandalf. Certainly many theologians would contend that Jesus' teachings are meaningless if he was not real (and not really the Son of God). But even if we grant that premise, it is apparent that on a practical level, dealing with ordinary non-theologian people, the logical contradictions wouldn't impair the pragmatic efficacy of treating the story of Jesus like any other fictional story with a moral. So one can believe that Jesus didn't exist and yet not have to reject the story as irrelevant (indeed, this is my approach to much of what's in the Bible).

The real question, then, is: if we prove that Jesus never existed, should (or may) people continue to believe otherwise? For some people, I would say yes. There's a great diversity in the human psyche, so for some, but not all, people, belief in the historical reality of Jesus may be the optimal strategy for leading a happy and moral life. Of course, taking this pragmatic angle opens up the question of how we prove that Jesus never existed. "Jesus never existed" is not so much a Truth as a theory that is (in this hypothetical scenario) most useful in making sense of historical data, and thus recommends itself to people whose need to have an explanation of a certain set of historical information outweighs their dependence (if any) on belief in Jesus for happiness and morality.

I haven't read Sagan, but anti-fable and anti-pragmatism statements like his often rest on an implicit pragmatism. Rather than showing that belief in the truth is good for its own sake, the argument is that you can't fool yourself forever, and eventually your fable will get you in trouble -- as when Stalin was caught unprepared because of his insistence on believing that Hitler would honor the non-agression pact (my honors thesis was an exploration of how this type of problem plagued Soviet policy toward the Aral Sea). Basically, it amounts to the (important) argument that truth is more useful than many proponents of crude pragmatism realize (an argument also made by one of the original Pragmatists, John Dewey). Their error lies in attributing too high a utility to truth and too easy a separation between truth and fable, often springing from mistakenly assuming that the ends people's theories about the world must serve are mostly the same for everyone.