BOSTON Atheists are under attack these days for being too militant, for not just disbelieving in religious faith but for trying to eradicate it. And who's leveling these accusations? Other atheists, it turns out.
Among the millions of Americans who don't believe God exists, there's a split between people such as Greg Epstein, who holds the partially endowed post of humanist chaplain at Harvard University, and so-called "New Atheists."
Epstein and other humanists feel their movement is on verge of explosive growth but are concerned it will be dragged down by what they see as the militancy of New Atheism.
The most pre-eminent New Atheists include best-selling authors Richard Dawkins, who has called the God of the Old Testament "a psychotic delinquent," and Sam Harris, who foresees global catastrophe unless faith is renounced. They say religious belief is so harmful it must be defeated and replaced by science and reason.
Epstein calls them "atheist fundamentalists." He sees them as rigid in their dogma and as intolerant as some of the faith leaders with whom atheists share the most obvious differences.
Next month, as Harvard celebrates the 30th anniversary of its humanist chaplaincy part of the school's chaplaincy corps Epstein will use the occasion to provide a counterpoint to the New Atheists.
"Humanism is not about erasing religion," he said. "It's an embracing philosophy."
In general, humanism rejects supernaturalism, while stressing principles such as dignity of the individual, equality and social justice. If there's no God to help humanity, it holds, people better do the work.
The celebration of a "New Humanism" will emphasize inclusion and diversity within the movement and will include Pulitzer Prize-winning scientist E.O. Wilson, a humanist who has made well-chronicled efforts to team with evangelical Christians to fight global warming.
Part of the New Humanism, Wilson said, is "an invitation to a common search for morally based action in areas agreement can be reached in."
The tone of the New Atheists will only alienate important faith groups whose help is needed to solve the world's problems, Wilson said.
"I would suggest possibly that while there is use in the critiques by Dawkins and Harris, that they've overdone it," he said.
Harris, author of "Letter to a Christian Nation," sees the disagreement as overblown. He thinks there's room for multiple arguments in the debate between scientific rationalism and religious dogmatism. "I don't think everyone needs to take as uncompromising a stance as I have against faith," he said.
But, he added, an intellectual intolerance of people who strongly believe things on bad evidence is just "basic human sanity."
"We do not jail people for being stupid, but we do stop listening to them after a while," he said in e-mailed comments.
Harris also rejected the term "atheist fundamentalist," calling it "a silly play upon words." He noted that, when it comes to the ancient Greek gods, everyone is an atheist and no one is asked to justify that to pagans who want to believe in Zeus.
"Likewise with the God of Abraham," he said. "There is nothing 'fundamentalist' about finding the claims of religious demagogues implausible."
Some of the participants in Harvard's celebration of its humanist chaplaincy have no problem with the New Atheists' tone.
Harvard psychologist and author Steven Pinker said the forcefulness of their criticism is standard in scientific and political debate and "far milder than what we accept in book and movie reviews."
"It's only the sense that religion deserves special respect the exact taboo that Dawkins and Harris are arguing against that people feel that those guys are being meanies when applying ordinary standards of evaluation to religion," Pinker said in e-mailed comments.
Dawkins did not respond to requests for comment. He has questioned whether teaching children they could go to hell is worse in the long term than sexually abusing them and compares the evidence of God to evidence of unicorns.
A 2006 Baylor University survey estimates about 15 million atheists in the United States.
Not all nonbelievers identify as humanists or atheists, with some calling themselves agnostics, freethinkers or skeptics. But humanists see the potential for unifying the groups under their banner, creating a large, powerful minority that can't be ignored or disdained by mainstream political and social thinkers.
Lori Lipman Brown, director of the Secular Coalition of America, sees a growing public acceptance of people who don't believe in God, pointing to California U.S. Rep. Pete Stark's statement this month that he doesn't believe in a supreme being. Stark is the first congressman to acknowledge being an atheist.
As more prominent people such as Stark publicly acknowledge they don't believe in God, "I think it will make it more palatable," Brown said.
But Epstein worries the attacks on religion by the New Atheists will keep converts away.
"The philosophy of the future is not going to be one that tries to erase its enemies," he said. "The future is going to be people coming together from what motivates them."