Atheist vs. agnostic

Many people are confused about the meaning and usage of the terms atheist vs. agnostic. A frequent claim made by theists is that being an atheist implies certainty about the non-existence of God. At the other extreme, many people apply the term agnostic as if it simply means waffling on the issue of whether or not God exists. The following explanation is presented as an attempt to clarify these terms.

Belief
Theism addresses the issue of belief. For any claim asserting the existence of a god, a theist is an individual who accepts (or positively believes) that the claim is true and an atheist (literally, "one without theism") is someone who does not.

Note that this doesn't mean that theists must accept any existence claim about any god. One can be a theist with respect to some claims and an atheist with respect to others. In particular, followers of one religion are typically atheists with respect to the gods of all other religions.

To be more precise about the issue of belief, consider the two possible claims one can make regarding the existence of a god:
 * 1) The god exists.
 * 2) The god does not exist.

There are two positions one can take with respect to either claim:
 * 1) Belief or acceptance of the claim.
 * 2) Disbelief or rejection of the claim.

For claim number 1 (the god exists), the theist takes the first position (belief), while the atheist takes the second (disbelief).

For claim number 2 (the god does not exist), the theist takes the second position (disbelief), while the atheist can hold either position (belief or disbelief).

Note that one may wish to consider a "third option" of simply reserving judgment. This is actually consistent with position number 2. "Disbelief" means lack of belief. If someone reserves judgment, then clearly they don't believe — and thus they disbelieve, which is position 2. In light of this, one must interpret the term "rejection of a claim" as meaning "lack of acceptance" (and thus, in a sense, only a rejection "if forced to choose right now"). In particular, the term "rejection" should not be interpreted as being based in any way on an acceptance of the opposite claim.

Therefore, atheists need not positively believe that no gods exist. Some do, and this position is often known as strong atheism. By contrast, other atheists hold that neither claim is sufficiently supported by evidence to justify acceptance, a position known as weak atheism. (The weak atheism position is often confused with agnosticism, which is discussed below.)

While logic dictates that exactly one of the two claims above must be true (assuming the concept of "god" is sufficiently well-defined in the first place) — and so if one claim is not true the other must be true — there is no such implication in the case of belief. Just because someone doesn't believe something, that doesn't mean they believe the opposite. (For example, not believing the claim that the inventor of the Slinky died in a spring-related accident doesn't mean one positively believes that he didn't die that way.) This is one reason why the theist's accusation that atheism requires "just as much faith" as theism is unfounded (except possibly in the case of particularly strong forms of strong atheism, as discussed below).

Knowledge
Gnosticism (in the general sense being discussed here) addresses the issue of what one knows or claims to know. For any claim regarding the existence of a god, a gnostic is an individual who claims knowledge that the assertion is true and an agnostic (literally, "one who lacks knowledge") is someone who makes no such claim.

Obviously, based on these definitions, the terms atheist and agnostic are not mutually exclusive. One can be an agnostic atheist, meaning someone who doesn't claim to know whether or not a god exists (agnostic) but doesn't find belief to be justified by evidence or argument (atheist). Other ways in which the terms agnostic, gnostic, atheist and theist can be combined are discussed below.

Typically, the gnostic's assertion of knowledge is esoteric and may well be attributed to divine revelation. In some cases, the gnostic will assert that the knowledge of a god's existence is available to anyone, although rarely through empirical, scientific evidence.

Many people assume that atheists believe that gods can be proved not to exist, but this isn't strictly true. In fact, there is no term commonly used to describe such an atheist, since their position would be even more extreme than strong atheism. Such a person might be called an "untheist" or "antitheist", perhaps. According to our definitions, they would simply be called a gnostic atheist who happens to think that his or her belief can be proven.

While many atheists would probably agree that given any sufficiently detailed description of a god, that particular god could be convincingly argued against, that is very different from constructing an airtight proof of universal non-existence. (See also Proving a universal negative and You can't prove God doesn't exist.)

Combining terms
As the terms we have been discussing concerning belief and knowledge aren't mutually exclusive, it is possible to combine them into four different descriptions:

Note that case 1 describes weak atheism, but case 2, as stated, is actually stronger than strong atheism, since it includes a claim of knowledge.

Clearly the distinction between belief and knowledge is an important one, and it is this distinction that is often misunderstood, or simply ignored, by self-identified "believers".

Other epistemological issues
A common usage of the term agnostic denotes a philosophical position invented by Thomas Huxley. This type of agnostic would claim that the answers to questions about the existence of gods are both unknown and fundamentally unknowable. In addition, many agnostics believe that such questions are essentially meaningless, as the concept of "god" is ill-defined.

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 Agnosticism), yet we constantly make claims of knowledge. You may "know" who your (birth) mother is, for example &mdash; but you could be wrong. For many gnostic 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".