"Agnosticism" is the view that the existence of any gods is unknown or unknowable. The term was coined by [[http://en.wikipedia.org/wiki/Thomas_Henry_Huxley Thomas Henry Huxley]] in 1869, though the concept has been [[http://www.uctaa.net/articles/meds/med13/med244.html kicking around for much longer]]. Agnostics usually appear under the category of "non-believers" along with atheists. Incidentally, there is a large degree of overlap with UsefulNotes/{{atheism}}.

Agnosticism is not mutually exclusive with atheism or theism since it is a question of if someone believes they can or cannot know a god exists. While agnostics generally agree with atheists on the subject of belief in God or gods, they disagree on the subject of disbelief: a common agnostic criticism of atheism is the scientific principle that "absence of proof does not constitute a disproof". Once again, this is only an issue for the minority of atheists who are gnostic/strong/positive/hard atheists, who are a minority.

There are many different strands of agnostic thought, including the following :
* Belief that God is inherently "unknowable". Adherents to this type of agnosticism believe that one ''cannot'' know of God's existence, role, appearance or ethics (assuming that it might exist at all).
* Belief that God's existence is neither proven nor disproven. That is, that while God may be "knowable", we do not "know" yet either way.
* Agnostic atheism, where there is not enough evidence to know that a god exists, but it is not impossible that one does.
* Agnostic theism, where God probably exists based on the evidence at hand, but that it is not certain.
* Apatheism (a {{portmanteau}} of "apathy" and "theism"), where the individual simply does not care whether God does or does not exist, or finds no practical reason to believe either way.

Agnosticism can also be used to describe someone who is undecided, or just non-committed to any particular belief. For example, in experimental physics, there is a concept called "model agnosticism", which describes a state of mind in which the experimenter has multiple theories (or "models"), but keeps an open mind about which of them is true pending the results of the experiment.

Agnostics have on occasion been condemned by followers of various religions for their lack of belief (often being lumped in with atheists in the process). They have also been criticized by prominent agnostic atheist UsefulNotes/RichardDawkins for "fence sitting" -- i.e. not having the conviction to outright admit to being an atheist. Self-described agnostics Creator/CarlSagan and UsefulNotes/NeilDeGrasseTyson fall into this camp, admittedly calling themselves agnostics because they have to deal with politics where atheism is still a dirty word. It can also be a label used because "atheist" is defined by some as ''knowing'' gods do not exist.

Many agnostics find this accusation insulting, and parallels have been drawn between agnosticism and bisexuality, as bisexuals can also face discrimination from both ends of a spectrum on similar grounds. However, this view supposes that belief is a spectrum rather than binary, as if someone could only half believe. Critics also point out that there is already a term for someone who does not actively believe in any deities: atheist.

Agnostic theism is more unusual, but some have argued philosophers such as the [[{{UsefulNotes/Existentialism}} existentialist]] Soren Kierkegaard qualify. Kierkegaard felt the existence of God was something which no one could rationally prove, and they had to make a "leap of faith." The same may be found in fideism, a view arguing that belief in God must rest upon faith alone, wholly independent of reason.