What does it mean to be an atheist in a God-fearing nation like the United States? Anywhere from 90 percent to 95 percent of Americans profess to believe in a deity. No wonder some self-avowed atheists are proud of their dissident status. A Web site of "atheist celebrities" lists, among others, Woody Allen, Richard Avedon, Marlon Brando, Jodie Foster, Jack Germond, Christopher Hitchens, Jack Nicholson, Penn and Teller, and Gore Vidal. Hitchens and Vidal have trumpeted their atheism in print; ditto for the columnist Katha Pollitt and the science writer Natalie Angier. Since these four are intellectuals, we might expect from them some powerful arguments for the nonexistence of God, arguments that would shake the faith of a reasonable believer. But a look at their public statements makes it doubtful whether they have even earned the honorific "atheist."
Katha Pollitt may have declared herself an atheist on Crossfire, but she neglected to disclose her grounds for taking this position. In fact, she says, she is not even anti-religion. She is merely "anti-clerical": She doesn't like priests and ministers. Well, neither did Voltaire, but he was not an atheist. Natalie Angier, in her "Confessions of a Lonely Atheist," complained that "nothing seems as despised, illicit and un-American as atheism." But she adduced no reasoning that might bring other Americans into her camp and hence render her less lonely. Gore Vidal has had great fun railing against the Judeo-Christian-Islamic "sky-god," in whose name all sorts of evils have been committed. Then he cites the countervailing wisdom of the deist Thomas Jefferson.
Of all the public-intellectual atheists, the most stalwart and lucid is probably Christopher Hitchens. "I'm an atheist," Hitchens said in a recent interview. "I'm not just neutral about religion, I'm hostile to it. I think it is a positively bad idea, not just a false one." Being anti-religion, however, is not intellectually equivalent to affirming the nonexistence of God. Bertrand Russell, who occupied the same ground as Hitchens, was careful to stress that he was agnostic, not atheist: "An atheist, like a Christian, holds that we can know whether or not there is a God. … The agnostic suspends judgment, saying that there are not sufficient grounds either for affirmation or denial."
Being an atheist is a philosophical stance. It is not enough simply to declare yourself one: That is mere dogmatism—like announcing, without further argument, that you don't believe in free will or objective values. If you wish to be an intellectually interesting atheist, you are obliged to give some evidence for your position. After all, there are plenty of rational and fiercely intelligent thinkers—Garry Wills, to name one—who don't agree with you.
The evidentiary ledger has two sides: reasons for believing God exists, and reasons for believing God doesn't exist. It is sometimes claimed that science has annihilated all the reasons in the pro-God column. That was close to being true in the 19th century. Victorian geologists were able to show that the Earth was vastly older than the Bible supposed. Chemists demystified life by synthesizing organic molecules in the lab. Darwin scuppered the notion that a divine artificer was needed to explain the marvelously adaptive designs found in nature. By the end of the 19th century, a purely material worldview—one that excluded supernatural explanations or spiritual phenomena, let alone a deity—seemed quite plausible.
That is pretty much the worldview staked out by today's public atheists. They haven't come to terms with 20 th-century science, which revived some of the reasons in the pro-God column. The discovery that the universe began with a creationlike Big Bang around 13 billion years ago, for example, breathed new life into the so-called cosmological argument, which posits God as the first cause of nature. The discovery that the fundamental laws of nature contained constants that appear to have been fine-tuned so that the cosmos would eventually yield intelligent life lent new credence to the design argument for God's existence. Quantum theory dematerialized reality, making the cosmos seem more like a thought than like a machine. But whose thought?
Such scientific ideas have been invoked by a new generation of what might be called "cosmic deists," including the physicists Paul Davies and Frank Tipler and the Oxford philosopher Richard Swinburne. In his book Nonzero, sometime Slate columnist Robert Wright observes that "an appraisal of the state of things from a scientific standpoint yields more evidence of divinity than you might expect." The divinity they have in mind is not the God of Abraham, Isaac, and Jacob, or even of Garry Wills. It is just some intelligent entity that somehow has something to do with the ordering of the universe.
At least one public atheist, the physics Nobel laureate Stephen Weinberg, has done much to undermine the new scientific pro-God evidence. Even if our universe had a beginning in time, Weinberg points out, current theory indicates that it may be part of an eternal network of Big Bangs. And in this many-universe model, it is not surprising that one of the universes should chance to be congenial to intelligent life, or that we should find ourselves in it. No need for the God hypothesis, Weinberg argues.
But is there any evidence against this hypothesis? Can the existence of God be disproved, or at least rendered highly improbable, as the atheist wishes to do? There are only two arguments for the nonexistence of God with any intellectual merit. The first says that the concept of God is incoherent: that, for instance, omnipotence gives rise to paradoxes (can God make a rock so big he can't lift it?), or that moral perfection is incompatible with divine freedom. This is very much a philosopher's argument, and it has been worked over to the point of inconclusiveness.
The second argument, the argument from evil, has much more force. How can there be evil in a world presided over by an all-powerful and all-good being? Either God was willing but unable to prevent Auschwitz, or he was able but unwilling. From Leibniz down to the present this argument has been countered with tremendous subtlety, most recently by the Notre Dame philosopher Peter van Inwagen. In a trio of lectures titled "Is It Possible To Disprove the Existence of God?" that he delivered this fall at Princeton, van Inwagen gave the classic free-will explanation of the existence of evil: To ask God to give me free choice between x and y and to see to it that I chose x instead of y is to ask him to do the logically impossible.