If someone who does not believe in any gods is an atheist, and agnostics do not believe in any gods, then aren't agnostics also atheists?
You may be confusing two different naming systems. Some people say all non-believers are atheists, but those aren't the same people who say that agnostics don't believe in gods.
Old system:
Atheists believe gods don't exist.
Theists believe gods do exist.
Agnostics don't believe either way.
New system:
Strong atheists believe gods don't exist.
Theists believe gods do exist.
Weak atheists don't believe either way.
Agnostics may believe one way or the other, but they don't know.
So, in the new system, all nonbelievers are atheists; and in the old system, agnostics are non-believers. If you mix the systems, you just cause confusion.
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Then agnosticism is the ridiculous claim that "i believe in this but I do not think it can ever to be established as true or not"?
Agnosticism is not knowing. There's nothing ridiculous about not knowing something unless in circumstances where you
should know.
My mom's a Christian who once said, "I struggle with my faith every day." So, she's not a gnostic theist. I'm a strong atheist who believes that there are no gods. I can prove that some of them don't exist, but I don't see any way to prove that no gods exist. So I'm not gnostic either.
I don't see why you would call either of these positions "ridiculous." There are lots of things you believe that you don't know. That's part of the human condition.
If your claim is that we shouldn't believe in anything we don't know for sure, well, that's ridiculous.
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Every agnostic I've seen has perpetuated a misunderstanding of what atheism is.
I'm an agnostic strong atheist. How do I perpetuate misunderstanding?
As someone still struggling with this thought, I think Bilby summed it up very well.
Yes, agreed!
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'I believe in this, but do not think it can ever be established as true or not'
What is the meaning of the verb 'believe' in this context? Belief, as I understand it, is the acceptance of something as true.
It's just the regular normal English-language use of "believe" and "know." You can believe something on less evidence than you can know it. Here's dictionary.com:
Believe: "to have confidence in the truth, the existence, or the reliability of something, although without absolute proof that one is right in doing so."
Know: "to perceive or understand as fact or truth; to apprehend clearly and with certainty"
That's not confusing. One can believe without certainty. One cannot know without belief.
Is it just another way of saying 'god probably exists, but I can not be 100% certain'?
No. You're confusing the state of mind (belief) with the justification for the state of mind (god probably exists). It might help if you think of someone with an irrational belief ("It's been sixteen days since the cave-in, and they have no food or water down there, but I believe they're still alive!").