Definition
Agnosticism is the position that the existence of God is not known — and, in some versions, cannot be known. The term was coined in the nineteenth century by the biologist Thomas Henry Huxley to describe a refusal to claim knowledge that one does not actually possess. Agnosticism concerns what can be known, whereas atheism and theism concern what one believes; the two questions are distinct, and a person may answer them differently.
An agnostic withholds commitment, holding that the available evidence does not settle the matter. This makes agnosticism a claim about the limits of human knowledge as much as about God.
Why it matters
How it works
Temporary agnosticism, in Dawkins's terms, applies when there is a fact of the matter but we currently lack the evidence to decide it. Permanent agnosticism applies when a question is thought to be beyond any possible evidence. Dawkins places the God question in the first category: he treats it as an empirical claim about which the evidence, in his view, points strongly one way, even if absolute proof is unavailable.