In his Autobiography, written in 1876, Darwin wrote: “The mystery of the beginning of all things is insoluble by us; and I for one must be content to remain an Agnostic”. This term had been coined in an 1869 lecture by Thomas Henry Huxley, a biologist known as ‘Darwin’s bulldog’ for his advocacy of Darwin’s theory of evolution. The term comes from the Greek words ‘agnostos’ which means ‘ignorant’, and ‘gnosis’ which means ‘knowledge’. Huxley explained it as follows: “Agnosticism, in fact, is not a creed, but a method, the essence of which lies in the rigorous application of a single principle… Positively the principle may be expressed: In matters of the intellect, follow your reason as far as it will take you, without regard to any other consideration. And negatively: In matters of the intellect do not pretend that conclusions are certain which are not demonstrated or demonstrable”.
Agnosticism is thus the view that the truth of certain opinions is unknown or unknowable. In the religious context, it is often suggested that an agnostic is someone who neither believes nor disbelieves in God. But agnostics, while not knowing if a god exists or not, have tended to be highly sceptical of the idea. This scepticism has a long history, going back at least to ancient Greece and philosophers like Protagoras, though open expression of it was often dangerous and therefore rare even into the 18th century, with the notable exception of David Hume. After Darwin, agnosticism developed rapidly and even became almost respectable, with agnostics being regarded as reasonable people, in contrast to atheists, who were often regarded as closed-minded and dogmatic.
It is thus frequently argued that atheism springs from the same deluded and potentially dangerous quest for certainty as the dogmatic tendencies in the religion it opposes. But this is only one interpretation of atheism, which is simply an absence of belief in the existence of gods. The certainty or lack of it varies from one atheist to another. Not believing that something is true is not equivalent to believing that it is false: we may simply have no idea whether it is true or not. This is basically the same as agnosticism. Some people make the distinction that agnosticism is not about belief in a god but about knowledge though, logically, agnosticism is compatible with both theism and atheism. A person can believe in a god (theism) without claiming to know for sure if that god exists – the result is agnostic theism. On the other hand, a person can disbelieve in gods (atheism) without claiming to know for sure that no gods can or do exist – the result is agnostic atheism. Indeed it is quite common to be an agnostic atheist, which merely goes to prove that the words are ultimately just convenient labels, and it is what we mean by them that is important. Since a Humanist goes further than mere agnosticism or atheism in believing in a positive god-free philosophy, it is entirely possible to be an agnostic atheist Humanist.