Oh! I do! I think!
Atheism is the belief that God doesn't exist, but only insofar as the person knows that God doesn't exist.
And since one can't prove a negative, then let's just say he strongly suspects there is no God, which means he goes by faith.
But only insofar as he can ascertain same; if he can't ascertain same, then he can claim he doesn't know God exists, but until he can, he will claim 'weak atheism'.
In other words, he will be a 'weak atheist', until a 'strong atheist' shows otherwise by proving a negative that one can't prove in the first place.
OR, until someone comes along and proves beyond a shadow of a doubt -- not "suspects", like he's allowed to do with his beliefs, but proves beyond a shadow of a doubt that God exists, then he will drop his weak atheism in favor of theism, until such time as someone falsifies this proof, then he will join the ranks of weak atheism again, until, of course a strong atheist comes along and...