Go for the jugular of fundamentalist mindsets. It is the enemy of freedom of thought. It is plagued by the disease of black-and-white thinking. It divides and often conquers. Yet, fundamentalism is harder to detect than one might realize. It's easy to see it when someone on the Religious Right discriminates against women or gays or promotes a controlling morality based on literalist views of the Bible. It's harder to see when held by progressive secularlists who rightly critique right-wing fundamentalism but succumb to black-and-white thinking in their response.
Years ago I was wrong about atheists. I rejected their world view and their motivation. I wrongly believed they chose to deny God because of their selfish desire to live autonomously in a universe free from moral restraints. I since learned that there are varieties of atheists, just like there are varieties of theists, and many atheists are moral and upright individuals. In fact, one of my heroes these days is an atheist: Ayaan Hirsi Ali, who wrote Infidel, and fights for the rights of Muslim women. But I also learned that some atheists are fundamentalists. Like fundy religionists, they don't fight fair, have an ax to grind, and refuse to go where the evidence leads.
Richard Dawkins, who regularly calls believers delusional, falls in the fundy-atheist category, I would say, along with others among "the new atheists." Atheist Michael Ruse said Dawkin's book, The God Delusion, makes him embarrassed to be an atheist. I respect Ruse for his candor. Antony Flew, the most famous atheist in Europe, changed his position and became a deist. When I read why in his book (There is a God), I gained a new respect for him and his position, even during the time he was an atheist. According to Frank Schaeffer in his new book, Patience with God, atheist Daniel Dennett argues decently and is no fundamentalist. (Dennett, author of Breaking the Spell is one of "the-gang-of-four" new atheists along with Dawkins, Christopher Hitchens, and Sam Harris).
There is such a thing as atheistic fundamentalism. I've learned there is a balanced way to approach religious arguments--in fact any controversial argument--that respects the facts over dogma and always attempts to go where the evidence and one's honest life reflection leads. This leads me to want to squash fundamentalism wherever it rears its ugly head--including inside myself--and pursue this balanced path instead. Care to join me?