Atheist vs Agnostic
Many people are confused about the meaning and usage of these terms. A frequent claim is that being an atheist implies certainty about the non-existence of God. The following explanation is presented to clarify these terms in common usage.
Belief
Theism addresses the issue of belief. For any claim about the existence of a god, theists are individuals who accept that this claim is true. One way of stating this is that the theist possesses the positive belief that this god claim is true.
Atheism literally means "without theism". An atheist is someone who does not accept, as true, claims about the existence of a god. This does not necessarily mean that atheists actively believe that no gods exist.
Considering the claims regarding the existence of a god, there are two possible claims:
- God exists
- God does not exist
For either claim, there are two positions one can take with regard to belief:
- belief or acceptance of the claim
- disbelief or rejection of the claim
For claim number 1 (God exists), the theist's position is one of belief, while the atheist's position is one of disbelief.
For claim number 2 (God does not exist), the theist's position is one of disbelief, while atheists can hold either position.
Some atheists actively believe that no god exists while others hold that neither claim is sufficiently supported to justify acceptance. These positions are often labeled strong atheism and weak atheism, respectively. Additionally, some individuals confuse the weak atheism position with agnosticism.
Knowledge
Gnosticism (in the sense used here) addresses the issue of what one knows or claims to know. For any claim about the existence of god, gnostics are individuals who claim to know that the claim is true. Typically, this claim of knowledge is esoteric and may be attributed to divine revelation. In some cases, the gnostic will assert that this knowledge is available to anyone though rarely through empirical, scientific evidence.
An agnostic is, literally, someone who does not claim to know that such claims are true. An additional, and common, usage of the term agnostic exists as a label for the philosophical position invented by Thomas Huxley. Those individuals adopting this label claim that the answers to questions about the existence of gods are unknown and unknowable. Additionally, many claim that the questions are essentially meaningless as "god" is ill-defined.
Combining Terms
Notice that the terms "atheist" and "agnostic", by these definitions, are not mutually exclusive. You could be an agnostic atheist, meaning you don't think one can know whether or not a god exists, but you don't feel that belief is justified by evidence or argument.
Many people assume that atheists believe that gods can be proved not to exist, but this isn't strictly true and there is no word to describe this. You could call such a person an "untheist" or "antitheist", perhaps. Or, you could just call such a person a "gnostic atheist", one who doesn't believe in a god and thinks that his non-belief can be proven.
As the terms aren't mutually exclusive, it's possible to combine them into four descriptions:
Case 1 is sometimes referred to as weak atheism and case 2 as strong atheism. Only strong atheism positively asserts that there are no gods.
It's important to note, when discussing the complicated issues of knowledge and epistemology, that these claims of knowledge do not necessarily require absolute omniscience. It can be argued that we can never truly "know" anything (see Wikipedia:Agnosticism), yet we constantly make claims of knowledge — you may "know" who your (birth) mother is, for example, but you could be wrong. For many gnostic atheists (strong atheists), their claim of knowledge stems from practical considerations. The positive assertion that "gods don't exist" can be made, and said to be "known", in the same spirit as the statement that "leprechauns don't exist".
Atheist vs Agnostic - Atheism - a Wikia wiki