When Charles Darwin unveiled his theory of natural selection, he said there was no inherent contradiction between it and religious belief. Maybe, for example, God had used natural selection as the instrument for creating intelligent life. One Anglican clergyman, in a letter to Darwin, suggested that this was actually a "loftier" conception of God than the old-fashioned idea of God creating humans the easy way, by just molding them out of dust.

Yet today many intellectuals think that if they're going to be true Darwinians, they should give up on any notion of divinity, any hope of higher purpose.

Why? In no small part because of the widely read philosopher Daniel Dennett. In his influential 1995 book "Darwin's Dangerous Idea," Dennett insisted that evolution is "purposeless"-and that, indeed, this lack of purpose is part of the "fundamental idea" of Darwinism. More recently, in a New York Times op-ed piece, he urged his fellow non-believers to unite and fight for their rights, depicting belief in God as contrary to a "naturalist" worldview.

I have some bad news for Dennett's many atheist devotees. He recently declared that life on earth shows signs of having a higher purpose. Worse still, he did it on videotape, during an interview for my website meaningoflife.tv. (You can watch the relevant clip here, though I recommend reading a bit further first so you'll have enough background to follow the logic.) [Editor's Note: Since this article was published, Dennett has claimed that it misrepresents his views. Robert Wright responds to Dennett here.]

Dennett didn't volunteer this opinion enthusiastically, or for that matter volunteer it at all. He conceded it in the course of a dialogue with me-and extracting the concession was a little like pulling teeth. But his initial resistance makes his final judgment all the more important. People who see evidence of some larger purpose in the universe are often accused of arguing with their heart, not their head. That's a credibility problem Dennett doesn't face. When you watch him validate an argument for higher purpose, you're watching that argument pass a severe test. In fact, given that he's one of the best-known philosophers in the world, it may not be too much to say that you're watching a minor intellectual milestone get erected.

The key to Dennett's change of view is the close connection between two separate questions: whether evolution has a purpose, and whether evolution has a direction. If you're going to believe, as that Anglican clergyman suggested, that a divine being set natural selection in motion, confident that it would eventually produce some species as intelligent as humans, then you have to believe that natural selection was likely to produce such intelligence from the beginning-that it was in this sense "directional".

On the question of directionality, Darwinians have long differed. Harvard biologist Edward O. Wilson considers intelligent life a likely product of natural selection; his late colleague Stephen Jay Gould argued otherwise. The evolution of creatures as smart as us was a fluke, Gould said, and its very unlikelihood was evidence that evolution had no purpose.

Before my dialogue with Dennett, his longstanding position had been that Gould was half wrong and half right: Natural selection had been fairly likely, sooner or later, to produce an intelligent species of some sort; but, no, this was not evidence that evolution had any overarching purpose, that natural selection was itself a product of design. Evolution had a direction of sorts, Dennett believed, but it definitely had no purpose.

But isn't this direction itself evidence of purpose? If a process naturally creates something as complex as great intelligence, doesn't that suggest the process was set up for that purpose? I've long thought so, but I had never been able to convince Dennett. He had read my book "Nonzero," whose closing chapters address this question, and had been unmoved. So I decided to take a new tack, with a new argument that drew on a famous incident in intellectual history.

The incident involves William Paley, a British theologian who wrote a book called "Natural Theology" in 1802, a few years before Darwin was born. In it he tried to use living creatures as evidence for the existence of a designer.

If you're walking across a field and you find a pocketwatch, Paley said, you know immediately that it's in a different category from the rocks lying around it. Unlike them, it is manifestly a product of design, featuring a complex functionality that doesn't just happen by accident. Well, he continued, organisms are like pocketwatches: they're too complexly functional to just happen by accident. So organisms must have a designer-namely, God.