If 'mere lack of belief' meant absence of any mental content then a stone would be an atheist.
I don't see why that would be an issue. If you want to call a stone an atheist, that's fine. I don't see it as any different to saying "this stone is not married" or "this stone does not own a stable" or "this stone is not a poet laureate". It's kind of a meaningless thing to say, but it is still at least just as technically accurate to state "this stone does not possess belief in a God".
Or, if a 'mere lack of belief' meant a lack of knowledge of the proposition wrt to deity, then a baby would be an atheist.
Correction: lacking of belief doesn't MEAN "lack of knowledge" - one can still possess knowledge and lack a belief. But total absence of knowledge of a claim necessitates disbelief in the claim by default. So, yes, a baby would be an atheist. Again, I don't see why this should be any more significant than saying "this baby is not married" or "this baby does not own a stable" or "this baby is not a poet laureate".
If both of these are true then atheists are foolish indeed .. Vacuum minds.
Again, no it doesn't. All it means that saying "I am an atheist" or being identified as an atheist
doesn't tell you anything other than that the individual lacks a belief in a God. An atheist can be an atheist for a variety of reasons, it just so happens that one of those reasons is that it is the default position with regards to all claims to not believe them. That doesn't mean ALL atheists are morons who disbelieve because they are ignorant, it just means
atheism is a broad term that can be defined as a state of disbelief and the default position with regards to the belief in God.
We are discussing the term 'lack of belief of deity'. In the context of an atheist it can only mean that an atheist has considered the question of existence of deity and has come to a conclusion that the deity in question does not exist.
How does it mean that? A lack of belief is a lack of belief, nothing more. It doesn't mean "lack of belief after considering the claim", it means "a LACK OF BELIEF". I doubt you would contest that someone who has never seen or heard of a boat could be said to not own a boat, so why is it so difficult to concede that a person who may never have been presented with or have the capacity to believe a claim doesn't possess a belief in that claim?