LOL you are incorrect sir...
Actually he is quite correct.
The definition of an Atheist: "Atheism is, in a broad sense, the rejection of belief in the existence of deities"
Do you accept or reject the god hypothesis? There are only two positions you can have, either you accept the claim of a god/gods or you don't. A theist says, "I think there is a thing that exists that we call god." This makes theism a position on the positive existence of a god. The prefix a- before a
consonant, meaning not, without: amoral; atonal; achromatic. [http://dictionary.reference.com/browse/a-]
Therefore atheism is 'not-theism or without-theism. Simply, one that doesn't hold the theistic viewpoint. Therefore, anyone that is not a theist is by definition atheist, including those that don't think the answer is knowable, agnostics.
If I ask you directly, "do you believe that a god or gods exist?" the answer is yes or no. Agnostic is not a valid answer to that question.
If I ask you whether you think it is possible to know whether gods exist, and you answer no,
that is the agnostic position.
and Agnostic is not a belief in god; it's a logical belief that there's no way anyone can know one way or another.
Correct. It does not answer the ontological question about whether one believes or not, only the epistemological one about the ability to know.
Our current understanding of modern cosmology posits the existence of universes outside of our own, i.e that we live in a multiverse. There is a problem that if we are stuck in our own universe it is quite likely that there cannot be any evidence that will tell us whether this view is correct or not. If you are agnostic on the idea of other universes, all that says is that you don't think it is possible to know. It can be either unknown, or even unknowable. However, if I ask you whether you think/believe that other universes exist outside our own, you can respond either yes or no regardless of whether or not the actual answer can be known.
In short, agnostic is an epistemic word that needs to be coupled with an ontology in order to make any sense.
I think you should take time to google and research the difference because you're way off the mark. Agnostic is a question of both belief and knowledge much like religion is. We "believe" that no one on earth could possibly have "knowledge" of a god's existence, so we do not "believe" tht there is or isn't a god. Google it, find out how wrong your definitions of Atheism and Agnosticism are, and then get back to me.
As I just pointed out, belief about the ability to know something and primary existential belief are two separate things and Google will tell you the same thing or different depending on who you read. However, if you read T.H. Huxley, the man that coined the term agnostic, you would find this -
Agnosticism, in fact, is not a creed, but a method, the essence of which lies in the rigorous application of a single principle. That principle is of great antiquity; it is as old as Socrates; as old as the writer who said, 'Try all things, hold fast by that which is good'; it is the foundation of the Reformation, which simply illustrated the axiom that every man should be able to give a reason for the faith that is in him, it is the great principle of Descartes; it is the fundamental axiom of modern science. Positively the principle may be expressed: In matters of the intellect, follow your reason as far as it will take you, without regard to any other consideration. And negatively: In matters of the intellect, do not pretend that conclusions are certain which are not demonstrated or demonstrable. That I take to be the agnostic faith, which if a man keep whole and undefiled, he shall not be ashamed to look the universe in the face, whatever the future may have in store for him.
It should be noted in all of the above that for Huxley, agnosticism was not a creed or a doctrine or even simply a position on the issue of gods; instead, it was a methodology with respect to how one approaches metaphysical questions generally.
http://atheism.about.com/od/aboutagnosticism/a/huxley.htm
Of course we can use Bertrand Russel's definition which is a bit different than Huxley's --
Are agnostics atheists?
No. An atheist, like a Christian, holds that we can know whether or not there is a God. The Christian holds that we can know there is a God; the atheist, that we can know there is not. The Agnostic suspends judgment, saying that there are not sufficient grounds either for affirmation or for denial. At the same time, an Agnostic may hold that the existence of God, though not impossible, is very improbable; he may even hold it so improbable that it is not worth considering in practice. In that case, he is not far removed from atheism. His attitude may be that which a careful philosopher would have towards the gods of ancient Greece. If I were asked to prove that Zeus and Poseidon and Hera and the rest of the Olympians do not exist, I should be at a loss to find conclusive arguments. An Agnostic may think the Christian God as improbable as the Olympians; in that case, he is, for practical purposes, at one with the atheists.
Here's Penn Jillette putting his $.02 in. Like me and Tyler, Penn appears to embrace the Huxley definition and sums it up fairly well
<em>[video=youtube;swkAGExZCII]http://www.youtube.com/watch?v=swkAGExZCII[/video]