Does One Need Evidence to Be an Atheist?

“[A]theism is just a statement of what an atheist doesn't believe rather than what he does believe” – Steve Hays

Over on Triablogue, Steve Hays posted an entry provocatively titled There’s no evidence for atheism. In it, he argues that atheists are essentially at a loss when it comes to producing a positive case for atheism, that the most they can do is raise objections to theism. One wonders if he has ever read George H. Smith’s book Atheism: The Case Against God. Of course, that raises the question of what constitutes a positive argument for a position. Then again, we should also not overlook the obvious fact that atheism is not a position to begin with; it is essentially a negation, a negation of theism. Sort of like a-Moonism: here “a-Moonist” would simply refer to someone who does not subscribe to the teachings of Sun Myung Moon. This does nothing to indicate which views to which an a-Moonist does subscribe. In fact, I’d wager that Steve Hays would consider himself an a-Moonist (in spite of Moonism’s Christian roots), just as I do given that I do not subscribe to the teachings of Sun Myung Moon.

So the question boils down to: Does one need a positive argument to support a negation of a belief system? Does one need evidence if he does not subscribe to a belief system? Do I need evidence to be an a-Moonist? If so, why?