An absolute negation needs the proof of the positive to be certain?
Absolute negation: "You will never be anything but a drunk."
To be certain, requiring no faith, the positive, observing the rest of the life, have had to been witnessed. Yet, how could it have? It has yet to exist in the circumstance.
The same can be said about Atheism?
Are Atheist Certain?
Once again I point out that "certainty" is an ambiguous word. It can mean a state of certainty, in which one's belief is factually correct, or it can mean a state of mind we might describe as "feeling certain," which is a whole lot different from being certain. One should be clear at all times to which meaning one is referring or you might as well not argue at all.
Being Atheist isn't certainty, its simply a position that doesn't believe the claims presented by theists. Its as simple as that, that try and extend the meaning Atheism to me certainty that there is no god or gods doesn't make sense. Unless you are talking about the types of atheist's when Richard Dawkins uses his scale of 1-7 I think.