Unveiling Agnosticism: Origins and Definitions in Philosophical Thought

What does it mean to truly know something? Most of us go through life assuming we know a great deal – the laws of physics, the facts of history, the people we love. But when the question turns to whether God exists, philosophers have argued for centuries that we may be stepping outside the boundaries of what human knowledge can actually reach. This is the core insight behind agnosticism – a term with a precise origin, a rich philosophical pedigree, and a meaning that is still widely misunderstood today.

The word itself: what does “agnostic” mean? 🔗

Agnosticism comes from the ancient Greek: the prefix a- meaning “without,” and gnōsis meaning “knowledge.” Put together, it simply means without knowledge. According to Britannica, the doctrine holds that humans cannot know of the existence of anything beyond the phenomena of their direct experience. It is not a statement about belief – about whether someone personally accepts or rejects God – but a statement about the limits of knowledge itself. That distinction is central to understanding the term correctly.

As the Stanford Encyclopedia of Philosophy explains, an agnostic in the epistemological sense maintains that it is not known – or cannot be known – whether there is a God. This separates agnosticism from both theism and atheism, which are positions about belief. Agnosticism is a position about knowledge.

Thomas Henry Huxley and the coining of the term 🔗

The word “agnostic” has a specific inventor: Thomas Henry Huxley (1825-1895), the English biologist and fierce advocate of Darwin’s theory of evolution. Wikipedia’s entry on agnosticism notes that Huxley coined the word in 1869 to denote people who, like himself, confessed to being ignorant about matters – including God’s existence – on which metaphysicians and theologians had long been dogmatising with the utmost confidence.

The occasion was a meeting of the Metaphysical Society in London, a gathering of thinkers who each identified with some philosophical or theological “ism” – Anglican, Catholic, Positivist, and so on. Huxley, finding himself without a label, invented one. As recorded in the Huxley File, he coined “agnostic” as a deliberate antithesis to “gnostic” – the early Church term for those who claimed special knowledge of divine mysteries. Where the Gnostic claimed to know, the agnostic admitted not knowing.

Crucially, Huxley did not frame agnosticism as a creed or a set of beliefs. As Philosophy Now explains, he insisted that agnosticism is a method, not a doctrine – a method of demanding evidence before accepting any claim as certainly true. For Huxley, it was morally wrong to assert certainty about something unless that certainty could be logically justified by evidence. This made agnosticism, in his view, not a passive shrug but an active intellectual commitment.

Huxley’s intellectual formation 🔗

Huxley’s agnosticism did not appear suddenly in 1869. Humanists UK notes that he saw doubt and agnosticism as the very starting point of intellectual progress, and had lost his religious faith well before he formulated the term. His thought was shaped early on by an essay from philosopher Sir William Hamilton on the philosophy of the “unconditioned” – the idea that the most important questions of the human mind might be fundamentally unanswerable. That reading stamped on his mind, long before the Metaphysical Society meeting, the conviction that the limitations of human intellect were not merely practical but theoretical.

Being a scientist, Huxley also approached agnosticism as a form of intellectual demarcation. EBSCO’s research overview on agnosticism notes that he believed it was important to stay within the bounds of what could be demonstrated or proven – and not to place undue weight on human reason alone when evidence was simply absent.

Ancient roots: skepticism before the word existed 🔗

While Huxley gave agnosticism its name, the underlying idea is far older. According to Wikipedia, the agnostic viewpoint had been expressed by earlier thinkers well before the 19th century. In the 5th century BCE, the Indian philosopher Sanjaya Belatthiputta refused to give definitive answers about metaphysical questions – whether the soul survives death, whether the world is eternal – a method later described as “eel-wriggling” for its consistent evasion of firm conclusions. The ancient Greek Sophist Protagoras expressed a strikingly similar stance toward the gods: he could not say whether they existed or what they were like.

In the Hellenistic tradition, Pyrrho of Elis, founder of Pyrrhonian skepticism, advocated for epoché – the suspension of judgment – when faced with questions that could not be definitively resolved. The Pyrrhonists held that for every argument, an equally compelling counter-argument could be produced, and so judgment ought to be suspended. This spirit of principled intellectual suspension runs directly through the history of what would eventually be named agnosticism.

Huxley himself was aware of this lineage. He called David Hume – the 18th-century Scottish philosopher of radical empiricism – “the Prince of Agnostics,” recognising in Hume’s skepticism about causality and metaphysical claims a precursor to his own position.

Kant’s critical philosophy and the limits of human knowledge 🔗

Perhaps the most philosophically rigorous foundation for agnosticism comes from Immanuel Kant (1724-1804). In his landmark work, the Critique of Pure Reason (1781), Kant drew a sharp distinction between the phenomenal world – the world of appearances, as it is filtered through human senses and cognition – and the noumenal world, or “things-in-themselves” as they exist independently of human perception.

As the Internet Encyclopedia of Philosophy explains, Kant argued that human knowledge is confined to objects that can, in principle, be given in experience. Anything beyond that – the soul, the cosmos as a totality, and above all God – falls into the “noumenal” realm and cannot be reached by theoretical reason. The Catholic Encyclopedia’s analysis of Kant summarises this succinctly: metaphysics fails in its attempt to tell us what God is, and such failure is not contingent but inevitable given the structure of human cognition.

Kant did not conclude that God does not exist. Rather, as the Stanford Encyclopedia of Philosophy’s entry on Kant’s philosophy of religion makes clear, he sought to establish the limits of theoretical knowledge precisely in order to make room for faith – a different, practically grounded mode of assent. God, for Kant, was not a matter of scientific proof but of moral and practical necessity. This nuanced position – neither atheism nor confident theism – has led many scholars to see Kantian philosophy as one of the strongest intellectual pillars underpinning modern agnosticism.

The interdisciplinary resource Inters.org confirms that Kant’s metaphysical agnosticism decisively influenced both philosophical and scientific agnosticism in the 19th and 20th centuries, showing how his framework derived partly from Hume’s critique of causality and partly from the rationalist tradition’s own internal tensions.

Agnosticism is not a middle ground: clearing up a common confusion 🔗

One of the most persistent misunderstandings is that agnosticism is simply a halfway house between theism and atheism – a non-committal position for people who cannot make up their minds. This is incorrect. The agnostic position is not intellectual laziness; it is a positive claim about the boundaries of what human knowledge can reach.

Theism and atheism are positions about belief – one affirms God’s existence, the other does not. Agnosticism is a position about knowledge. The distinction matters because it is entirely coherent to hold both at once, which is precisely what gives rise to the two major hybrid positions in the philosophical literature.

Agnostic atheism 🔗

Agnostic atheism is the position of those who do not hold a belief in the existence of any deity, and who also maintain that such existence is unknowable or currently unknown. As Wikipedia explains, the agnostic atheist lacks belief in God but does not claim definitive knowledge that no God exists – they are atheistic in their lack of belief, while remaining agnostic about the epistemic question. This position is closely aligned with Huxley’s own formulation: he did not deny the logical possibility of God’s existence; he simply maintained that there was no evidence sufficient to justify claiming certainty either way.

The theologian and philosopher Robert Flint, in his 1887-88 Croall Lectures, was among the first to formally define this combination: if a person, after investigation, concludes that the existence of God is incapable of proof and ceases to believe in it on those grounds, they are both an agnostic and an atheist – an agnostic atheist.

Agnostic theism 🔗

Agnostic theism, by contrast, is held by those who believe in the existence of one or more gods but acknowledge that this belief cannot be grounded in certain knowledge. According to Wikipedia’s entry on agnostic theism, an agnostic theist believes in the existence of a deity but regards the basis of that proposition as currently unknown or inherently unknowable. The agnostic element here is not about abandoning belief, but about honestly acknowledging the epistemic limits of that belief – that faith is not the same as verified knowledge.

The Stanford Encyclopedia of Philosophy notes that since agnosticism is an epistemological position on knowledge – not a statement about what one should believe – it is fully compatible with both atheistic and theistic stances. This is what makes the agnostic framework so philosophically flexible and so persistently relevant.

Strong and weak agnosticism 🔗

Within agnosticism itself, philosophers distinguish two further forms. Strong agnosticism (also called “hard” agnosticism) holds that the existence or non-existence of God is not merely unanswered but fundamentally unanswerable – not just for any one individual, but for anyone, in principle, due to the inherent limitations of human cognition. Huxley himself leaned toward this stronger position. Weak agnosticism, by contrast, is the more modest claim that one personally does not know whether God exists and that current evidence is insufficient to decide – but it does not rule out the possibility that knowledge might one day become available.

EBSCO’s research overview characterises this distinction clearly: strong agnostics believe that no one can know whether a divine being exists, while weak agnostics allow for the possibility that someone – or future inquiry – might know. Both positions, however, share the foundational commitment to intellectual honesty: do not claim certainty where none can be justified.

Agnosticism as intellectual method, not just religious position 🔗

One of the most important points Huxley made – and one that is often missed – is that agnosticism is not confined to the question of God. It is a general intellectual method applicable to any domain where evidence is insufficient for certainty. In his own 1889 essay, Huxley wrote that the extent of the region of the uncertain will vary according to the knowledge and intellectual habits of each individual agnostic – and that there are many topics about which he knew nothing and which seemed out of reach of his faculties entirely.

This framing positions agnosticism not as a retreat from difficult questions but as an honest accounting of where the boundary of human knowledge actually lies. Humanists UK captures this well: Huxley believed that doubt was not weakness but the very starting point for progress in human knowledge. In his view, intellectual honesty demanded acknowledging what one did not – and could not – know.

What do you think? If the existence of God is genuinely beyond the reach of human knowledge, does that make agnosticism the most intellectually honest position available – or does it leave something important unanswered? And how should the distinction between not knowing and not believing shape the way we approach religious and philosophical questions in everyday life?

References

1. https://www.britannica.com/topic/agnosticism
2. https://plato.stanford.edu/entries/atheism-agnosticism/
3. https://en.wikipedia.org/wiki/Agnosticism
4. http://aleph0.clarku.edu/huxley/guide13.html
5. https://philosophynow.org/issues/99/Huxleys_Agnosticism
6. https://humanists.uk/humanism/the-humanist-tradition/19th-century-freethinkers/huxley/
7. https://www.ebsco.com/research-starters/religion-and-philosophy/agnosticism
8. https://iep.utm.edu/kantview/
9. https://www.newadvent.org/cathen/08603a.htm
10. https://plato.stanford.edu/entries/kant-religion/
11. https://inters.org/agnosticism
12. https://en.wikipedia.org/wiki/Agnostic_atheism
13. https://en.wikipedia.org/wiki/Agnostic_theism
14. https://mathcs.clarku.edu/huxley/CE5/Agn-X.html