Agnosticism is the philosophical and theological view that spiritual truths, such as the existence of God, gods or deities, is either unknown or inherently unknowable. The term and the related agnostic were coined by Thomas Henry Huxley in 1869 and are also used to describe those who are unconvinced or noncommittal about the existence of deities as well and other matters of religion. The word agnostic comes from the Greek a (without) and gnosis (knowledge). Agnosticism is not to be confused with a view specifically opposing the doctrine of gnosis and Gnosticism—these are religious concepts that are not generally related to agnosticism.
Agnostics may claim that it is not possible to have absolute or certain spiritual knowledge; Alternately they may claim that while certainty may be possible, they personally have no such knowledge. Agnosticism in both cases involves scepticism toward religious statements.
An agnostic might claim that religious statements or statements about the numinous are not or cannot be satisfactorily justified. In this case, it would be reasonable to reserve judgment. For instance, an agnostic might demand that religious statements be justified in the same way as scientific statements, perhaps in terms of the scientific method. Since this is adopting an attitude towards the quality of proof required to accept such statements, agnosticism becomes a matter of inclination rather than of logical proof. That is, one need only be willing to accept a different justification of religious statements in order to avoid agnosticism. Perhaps this explains why agnostics do not generally engage in proselytization. But since an agnostic simply denies certainty of what religious Truth might be, the lack of attempt to convert others may simply be that this works both ways; one cannot be certain which potential convert had, even if by accident, already been correct in his belief.
Some philosophical opinions
Among the most famous agnostics (in the original sense) were Thomas Henry Huxley, Charles Darwin, and Bertrand Russell. It has been argued from the works of David Hume, especially Dialogues Concerning Natural Religion, that he was an agnostic, but this remains subject to debate.
Thomas Henry Huxley
Agnostic views are as old as philosophical skepticism but the terms "agnostic" and "agnosticism" were created by Huxley to sum up his thoughts on contemporary developments of metaphysics about the "unconditioned" (Hamilton) and the "unknowable" (Herbert Spencer). It is important, therefore, to discover Huxley's own views on the matter. Though Huxley began to use the term "agnostic" in 1869, his opinions had taken shape some time before that date. In a letter to Charles Kingsley (September 23, 1860) he discussed his views extensively:
- "I neither affirm nor deny the immortality of man. I see no reason for believing it, but, on the other hand, I have no means of disproving it. I have no a priori objections to the doctrine. No man who has to deal daily and hourly with nature can trouble himself about a priori difficulties. Give me such evidence as would justify me in believing in anything else, and I will believe that. Why should I not? It is not half so wonderful as the conservation of force or the indestructibility of matter"..
- "It is no use to talk to me of analogies and probabilities. I know what I mean when I say I believe in the law of the inverse squares, and I will not rest my life and my hopes upon weaker convictions"..
- "That my personality is the surest thing I know may be true. But the attempt to conceive what it is leads me into mere verbal subtleties. I have champed up all that chaff about the ego and the non-ego, noumena and phenomena, and all the rest of it, too often not to know that in attempting even to think of these questions, the human intellect flounders at once out of its depth."..
And again, to the same correspondent, May 6, 1863:
- "I have never had the least sympathy with the a priori reasons against orthodoxy, and I have by nature and disposition the greatest possible antipathy to all the atheistic and infidel school. Nevertheless I know that I am, in spite of myself, exactly what the Christian would call, and, so far as I can see, is justified in calling, atheist and infidel. I cannot see one shadow or tittle of evidence that the great unknown underlying the phenomenon of the universe stands to us in the relation of a Father who loves us and cares for us as Christianity asserts. So with regard to the other great Christian dogmas, immortality of soul and future state of rewards and punishments, what possible objection can I — who am compelled perforce to believe in the immortality of what we call Matter and Force, and in a very unmistakable present state of rewards and punishments for our deeds — have to these doctrines? Give me a scintilla of evidence, and I am ready to jump at them."
Of the origin of the name "agnostic" to describe this attitude, Huxley gave (Coll. Ess. v. pp. 237-239) the following account:
- "So I took thought, and invented what I conceived to be the appropriate title of 'agnostic.' It came into my head as suggestively antithetic to the 'gnostic' of Church history, who professed to know so much about the very things of which I was ignorant. To my great satisfaction the term took."
Huxley's agnosticism is believed to be a natural consequence of the intellectual and philosophical conditions of the 1860s, when clerical intolerance was trying to suppress scientific discoveries which appeared to clash with a literal reading of the Book of Genesis and other established christian doctrines. Agnosticsm should not, however, be confused with deism, pantheism or other science positive forms of theism.
By way of clarification, Huxley states, "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" (Huxley, Agnosticism, 1889). A. W. Momerie has noted that this is nothing but a definition of honesty. Huxley's usual definition went beyond mere honesty, however, and he insisted that these metaphysical issues were fundamentally unknowable.
In 1879, as Darwin was writing his autobiography, a letter came asking if he believed in God, and if theism and evolution were compatible. He replied that a man "can be an ardent Theist and an evolutionist", citing Charles Kingsley and Asa Gray as examples, and for himself, he had "never been an Atheist in the sense of denying the existence of a God". He added that "I think that generally (and more and more as I grow older), but not always, that an Agnostic would be a more correct description of my state of mind."
On Thursday 28 September 1881 Darwin was visited by the atheists Doctor Ludwig Büchner and Edward Aveling (later the partner of Eleanor Marx). Darwin's son Frank was present, and Darwin's wife Emma Darwin invited their old friend the Revd. Brodie Innes. Darwin wittily explained that "[Brodie] & I have been fast friends for 30 years. We never thoroughly agreed on any subject but once and then we looked at each other and thought one of us must be very ill". In discussions after dinner Darwin asked his guests "Why do you call yourselves Atheists?", saying that he preferred the word "Agnostic". Aveling replied that "Agnostic was but Atheist writ respectable, and Atheist was only Agnostic writ agressive". Darwin responded by asking "Why should you be so aggressive?", wondering what was to be gained from forcing new ideas on people when freethought was "all very well" for the educated, but were ordinary people "ripe for it?" Aveling then asked what if "the revolutionary truths of Natural and Sexual Selection" had been confined to the "judicious few" and he had delayed publication of the Origin, where would the world be? Surely "his own illustrious example" encouraged freethinkers to proclaim truth "abroad from the house-tops", but while Darwin agreed that Christianity was "not supported by the evidence", he had been in no rush to force this idea on anyone and in fact "I never gave up Christianity until I was forty years of age."
Bertrand Russell's pamphlet Why I Am Not a Christian, based on a speech delivered in 1927, is considered a classic statement of agnostic belief. The essay briefly lays out Russell’s objections to some of the arguments for the existence of God before discussing his moral objections to Christian teachings. He then calls upon his readers to 'stand on their own two feet and look fair and square at the world', with a 'fearless attitude and a free intelligence'.
In Russell's later pamphlet Am I An Atheist Or An Agnostic? (subtitled A Plea For Tolerance In The Face Of New Dogmas), he confirms that he is an agnostic in the philosophical sense that he cannot know the truth of the existence or non-existence of God. However, in the same work he admits that calling himself an atheist would best convey his religious stance to a non-philosophical audience.
Logical positivists, such as Rudolph Carnap and A. J. Ayer, are sometimes erroneously thought to be agnostic. Using arguments reminiscent of Wittgenstein’s famous "Whereof one cannot speak, thereof one must be silent", they viewed any talk of gods as literally nonsense. For the logical positivists and adherents of similar schools of thought, statements about religious or other transcendent experiences could not have a truth value, and were deemed to be without meaning. But this includes all utterances about God, even those agnostic statements that deny knowledge of God is possible. In Language, Truth and Logic Ayer explicitly rejects agnosticism on the grounds that an agnostic, despite claiming that knowledge of God is not possible, nevertheless holds that statements about God have meaning.
Theists and strong atheists make statements about the world, the theist that 'God exists', the strong atheist that 'God does not exist'. Agnostics make the statement about these statements, 'one cannot know whether or not God exists'.
Agnosticism has suffered more than most expressions of philosophical position from terminological vagaries. Examples come from attempts to associate agnosticism with atheism. The "freethinking" tradition of atheism calls a lack of belief in the existence of any deities, "weak atheism" (or "negative atheism"). However, one can still draw a distinction between weak atheism and agnosticism by drawing a distinction between belief and knowledge, leading those who believe knowledge of God is not possible to claim agnosticism is about knowledge, while atheism/theism is about the lack of belief. Agnostic atheism is a combination of both.
Data collection services ,  often display the common use of the term, distinct from atheism in its lack of disputing the existence of deities. Agnostics are listed alongside secular, non-religious or other such categories.
Other variations include:
- strong agnosticism (aka hard agnosticism, closed agnosticism, strict agnosticism) — the view that the question of the existence of deities is unknowable by nature or that human beings are ill-equipped to judge the evidence.
- weak agnosticism (aka soft agnosticism, open agnosticism, empirical agnosticism) — the view that the existence or nonexistence of God or gods is currently unknown, but is not necessarily unknowable, therefore one will withhold judgment until more evidence is available.
- apathetic agnosticism (aka ignosticism or apatheism) — the view that the question of the existence of deities is meaningless because it has no verifiable consequences.
- model agnosticism — the view that philosophical and metaphysical questions are not ultimately verifiable, but that a model of malleable assumption should be built upon rational thought. Note that this branch of agnosticism differs from others in that it does not focus upon the question of a deity's existence.
- Collected Essays, Thomas Huxley, ISBN 1855069229
- Man's Place In Nature, Thomas Huxley, ISBN 037575847X
- Why I Am Not a Christian, Bertrand Russell, ISBN 0671203231
- Dialogues Concerning Natural Religion, David Hume, ISBN 0140445366
- Language, Truth, and Logic, A.J. Ayer, ISBN 0486200108