Understanding Epistemic Justification in the Context of the Linguistic Turn

What does it really mean to know something? Most of us assume that knowing requires more than guessing correctly – there must be some good reason behind the belief. This is the central concern of epistemic justification: the philosophical study of what makes a belief rational, well-grounded, and worthy of the label “knowledge.” The question became especially urgent in the 20th century, when a movement known as the linguistic turn reshaped how philosophers approached the problem entirely – shifting attention from the mind’s inner workings to language, social context, and the very concepts we use to talk about knowing.

What is epistemic justification? 🔗

In philosophy, epistemic justification refers to the reasoning, evidence, or process that makes a belief rational and acceptable – not merely held, but held for good reasons. The underlying goal is to distinguish genuine knowledge from lucky guessing or unfounded conviction.

For centuries, the standard definition of knowledge was justified true belief (JTB): you know something if (1) it is true, (2) you believe it, and (3) you are justified in believing it. As the Stanford Encyclopedia of Philosophy explains, all three conditions were treated as individually necessary and jointly sufficient for knowledge.

But this framework was shaken to its foundations in 1963, when philosopher Edmund Gettier published a short but devastating paper titled “Is Justified True Belief Knowledge?” Gettier’s counterexamples showed that a person can have a belief that is both true and justified – and yet still fail to have genuine knowledge, because the belief happens to be true only by coincidence. These became known as Gettier cases, and they fundamentally altered the landscape of epistemology.

Consider a simplified Gettier case: you glance at a clock on the wall, see it reads 3:00 PM, and form the belief that it is 3:00 PM. Your belief is true – it really is 3:00 PM. And your belief is justified – you reasonably trust wall clocks. But unbeknownst to you, the clock stopped exactly 12 hours ago. What Gettier problems demonstrate is that an individual can satisfy the classical conditions of justified true belief without actually possessing knowledge. Clearly, something is missing from the JTB account.

This gap forced philosophers to interrogate the concept of justification far more carefully – and four major theories emerged as competing answers.

The linguistic turn and epistemic justification 🔗

The linguistic turn in 20th-century philosophy refers to the rising influence of thinkers like Ludwig Wittgenstein, Willard Van Orman Quine, Bertrand Russell, and Rudolf Carnap, who argued that many deep philosophical problems were, at their core, problems about language and meaning. For epistemology, this meant that justification could no longer be treated as a purely private, internal matter. How we talk about belief, how we communicate reasons, and what our shared linguistic practices count as evidence – all of these became philosophically significant. Justification, it turned out, is not only about what goes on inside an individual mind, but also about how beliefs are expressed, evaluated, and challenged within a community of speakers.

This context helps explain why the four major theories of epistemic justification – foundationalism, coherentism, internalism, and externalism – each offer a different answer to the same basic question: where does the justification of a belief ultimately come from?

Foundationalism: building knowledge from the ground up 🔗

Foundationalism holds that the structure of justified belief is hierarchical. Some beliefs are basic beliefs – they are self-justifying or grounded directly in experience, and do not depend on other beliefs for their justification. All other beliefs derive their justification from these foundational ones, either through deduction, induction, or inference to the best explanation.

Descartes is the classical exemplar of this position. Seeking an indubitable foundation for all knowledge, he famously landed on cogito ergo sum – “I think, therefore I am” – as a belief so immediate that it could not be doubted. Contemporary foundationalists, however, are less demanding: they allow that non-basic beliefs can be justified by induction or abduction from basic beliefs, without needing those beliefs to be logically infallible.

Foundationalists are united in their conviction that there must be a kind of justification that does not depend on having justification for other beliefs – some beliefs must serve as the bedrock. The main challenge they face is explaining exactly what makes a basic belief “foundational,” and whether ordinary people actually possess enough basic beliefs to underwrite everything they claim to know.

Coherentism: justification as a web of mutual support 🔗

Coherentism rejects the idea of foundational beliefs entirely. Instead, coherentists favor a holistic picture of justification that treats all beliefs as members of an interconnected web, where no single belief stands above the rest. A belief is justified not because it rests on an indubitable base, but because it coheres – fits together consistently and mutually supportively – with the broader system of beliefs a person holds.

Coherentism holds that a belief is justified if it coheres with, or stands in mutual support with, the whole set of a person’s beliefs. Think of it less like a building (which needs a foundation) and more like a raft: every plank supports every other plank, and the whole structure floats together.

The major objection to coherentism is the isolation problem: a perfectly coherent set of beliefs could, in principle, be entirely disconnected from reality. A detailed and internally consistent fantasy world could be “coherent” without any of it being true. Critics also warn of circularity – beliefs justified by other beliefs within the same system never seem to be independently verified. Defenders of coherentism respond that coherence can boost justification that is already present, even if it cannot create it from scratch.

Internalism vs. externalism: where does justification live? 🔗

While the foundationalism-coherentism debate concerns the structure of justified belief, the internalism-externalism debate concerns its location – specifically, whether the factors that make a belief justified must be accessible to the believer themselves.

Internalism: justification from within 🔗

The basic idea of internalism is that justification is solely determined by factors that are internal to a person. For a belief to be justified, the individual must have access to the reasons, evidence, or mental states that support it. If you cannot, even in principle, reflect on and identify the grounds for your belief, then that belief is not genuinely justified – no matter how accurate it may happen to be.

The view that justification is a matter of having certain internal mental states is called internalism. Internalism captures an intuitive sense of epistemic responsibility: we feel that a properly justified belief is one the believer can actually give reasons for. Most foundationalists and coherentists historically operated within an internalist framework.

However, internalism faces serious objections. If justification requires full reflective access to one’s evidence, it becomes difficult to explain how animals, young children, or even ordinary adults with unreflective but accurate beliefs could be said to have knowledge at all. Internalists claim that there is a necessary internal epistemic condition for knowledge – that it would not be possible to know something unless the thinker has sufficiently good reasons available to reflection.

Externalism: justification from without 🔗

Externalism denies that the justifying factors must be internally accessible. Externalists argue that one cannot determine whether a belief is justified without looking at the believer’s external environment – including factors like the reliability of the process that produced the belief, whether the belief was caused by the actual state of affairs it describes, or whether it was formed in conditions conducive to truth.

The most influential form of externalism is reliabilism, developed by Alvin Goldman. In its simplest form, reliabilism holds that a belief is justified if and only if it is produced by a reliable psychological process – one that yields a high proportion of true beliefs. On this account, your perceptual belief that there is a tree in front of you is justified not because you can articulate the neuroscience of vision, but because visual perception is, as a matter of fact, a reliable belief-forming mechanism.

In 1979, Alvin Goldman published “What Is Justified Belief?” which departed from several well-entrenched positions on the nature of epistemic justification and came to be recognized as a paradigm shift – what Michael Williams later called “the Reliabilist Revolution.” Crucially, reliabilism does not require that the believer know or understand the process that makes the belief reliable – all that matters is that the process actually is reliable.

This move is both the strength and the vulnerability of externalism. It allows for a more expansive account of knowledge – one that covers animals, infants, and non-reflective adults – but critics argue that it leads to what might be called epistemic irresponsibility: a person can be “justified” in holding a belief without having any conscious access to why. Externalists deny that knowledge requires some internal epistemic condition – either because they deny that knowledge requires conditions like justification at all, or because they deny that any such condition depends wholly upon internal factors.

How these theories respond to the Gettier challenge 🔗

Each theory of justification offers a different response to the Gettier problem. Edmund Gettier’s formulation of the problem coincided with the rise of philosophical naturalism promoted by Quine and others, and was used as a justification for a shift towards externalist theories of justification. If the problem with Gettier cases is that justified true beliefs can be true “by accident,” then externalism – especially reliabilism – offers a direct remedy: a belief formed through a genuinely reliable process would not be accidentally true in the problematic way. The causal chain between the world and the belief would be appropriate.

Internalists, meanwhile, tend to seek a fourth condition to add to the JTB formula – typically some version of a “no false grounds” or “no defeater” condition. Philosophers have made many attempts to repair or replace the traditional definition of knowledge, resulting in several new conceptions of knowledge and justificatory support – all sparked by Gettier’s single two-and-a-half page article.

Why this debate still matters 🔗

The debate between foundationalism and coherentism, and between internalism and externalism, is not merely academic. It shapes how we think about the standards of knowledge in science, law, ethics, and everyday reasoning. Should a court require that a witness be able to consciously articulate why they believe what they believe (internalism)? Or is it sufficient that their eyewitness identification was produced under conditions known to be reliable (externalism)? Should we trust a scientific theory because it rests on foundational empirical observations, or because it coheres powerfully with a wider network of well-tested theories?

The linguistic turn added another dimension: it reminded epistemologists that justification is not a purely private affair. The standards by which we evaluate beliefs are shaped by language, social norms, and shared epistemic practices. Whether a belief counts as justified is partly a matter of what counts as a good reason within a community – a point that continues to drive contemporary debates in social epistemology and naturalized epistemology.

What do you think? If a belief is reliably formed but the believer has no awareness of why it is reliable, does it deserve to be called truly “justified” – or is conscious access to one’s reasons an essential part of what justification means? And between foundationalism and coherentism, which model better reflects how knowledge actually works in science or in everyday life?

References

1. https://plato.stanford.edu/entries/knowledge-analysis/
2. https://fitelson.org/proseminar/gettier.pdf
3. https://iep.utm.edu/gettier/
4. https://learn.academy4sc.org/video/the-gettier-problem-true-justified-belief-without-knowledge/
5. https://science.jrank.org/pages/9897/Knowledge-Linguistic-Turn.html
6. https://iep.utm.edu/foundationalism-in-epistemology/
7. https://press.rebus.community/intro-to-phil-epistemology/chapter/epistemic-justification/
8. https://plato.stanford.edu/entries/justep-foundational/
9. https://plato.stanford.edu/entries/justep-coherence/
10. https://iep.utm.edu/epi-just/
11. https://iep.utm.edu/int-ext/
12. https://plato.stanford.edu/entries/justep-intext/
13. https://www.rep.routledge.com/articles/thematic/justification-epistemic/v-1/sections/epistemic-and-non-epistemic-justification
14. https://www.rep.routledge.com/articles/thematic/reliabilism/v-1
15. https://plato.stanford.edu/entries/reliabilism/
16. https://en.wikipedia.org/wiki/Reliabilism
17. https://en.wikipedia.org/wiki/Gettier_problem