Atheism by definition means the absence of theistic belief.
Whereas, agnosticism is the idea that something is inherently unknowable.
Notice that by definition agnosticism has nothing to do with any beliefs, it
simply says whether something is knowable or not. Therefore by these
definitions agnosticism isn't a third alternative to atheism/theism. Only when a
person defines atheism as the actual denial of God is agnosticism an
alternative. But otherwise there are only two choices, atheism or theism.
For example, when a baby is born it (probably) has no concept of God or any
other form of theistic beliefs, therefore it is an atheism. On the other hand,
some religions believe that God is unknowable or beyond our simple human
comprehension, therefore they are agnostic theists.
So don't fall into the common misconception that all atheists assert the
nonexistence of God. There are degrees to atheism, some that do assert that
the concept of God is unintelligible and therefore God can't exist, and then
there are some atheists that are without theistic belief because the theist
cannot provide sufficient evidence to the existence of God(s).
... Steve Butts
... sbutts@purdue.edu