Theories of Knowledge and Justification
This area studies what propositional knowledge is and how beliefs come to be justified, weighing the classical justified-true-belief analysis against its rivals and asking whether justification rests on foundations, on coherence, or on factors inside or outside the believer's mind.
Definition
Theories of knowledge and justification are the systematic accounts of what it is to know a proposition and of how a belief acquires the positive epistemic status — justification or warrant — that distinguishes knowledge and reasonable belief from mere opinion.
Scope
The area covers the analysis of knowledge as a propositional state and the long debate over its conditions; the structure of epistemic justification in foundationalist, coherentist, and infinitist proposals; the regress problem that motivates these structures; and the internalism/externalism dispute over whether justifying factors must be cognitively accessible to the believer. It treats justification, warrant, and evidence as central, while leaving particular sources of knowledge, the Gettier literature in detail, and formal probabilistic models to neighbouring areas.
Sub-topics
Core questions
- What conditions must be met for a subject to know that a proposition is true?
- What is the difference between a belief that is merely true and one that is justified?
- Does justification rest on basic foundational beliefs, on coherence among beliefs, or on neither?
- Must the factors that justify a belief be accessible to the believer, or can they lie outside the mind?
Key theories
- Justified true belief (the traditional analysis)
- The classical view, traced to Plato's Theaetetus, holds that knowledge is belief that is both true and justified; Gettier's counterexamples showed these conditions are insufficient, launching the modern analysis-of-knowledge project.
- Foundationalism
- Justification ultimately rests on basic beliefs that are justified non-inferentially (for example by experience), with all other justified beliefs supported by inferential chains terminating in them.
- Coherentism
- No belief is justified in isolation; a belief is justified by its membership in a sufficiently coherent system of mutually supporting beliefs, with no privileged foundations.
- Evidentialism
- A belief is justified for a person at a time if and only if it fits the evidence that person then possesses, making justification a matter of evidential support rather than of causal or reliability conditions.
History
The project begins with Plato's Theaetetus, which tests and rejects several definitions of knowledge, and is refined through the early modern rationalist and empiricist accounts of justified belief. The twentieth century crystallised the justified-true-belief analysis, which Gettier's 1963 paper decisively challenged; the ensuing decades produced foundationalist, coherentist, evidentialist, and reliabilist responses that continue to structure the field.
Debates
- The structure of justification: foundations versus coherence
- Foundationalists argue that without basic beliefs the chain of justification regresses infinitely or circularly, while coherentists reply that no belief is genuinely self-justifying and that justification is holistic; Sosa frames this as the choice between the raft and the pyramid.
- Internalism versus externalism about justification
- Internalists hold that whatever justifies a belief must be accessible to the believer's reflection, as on evidentialist views, whereas externalists allow justification to depend on facts such as the reliability of belief-forming processes that the subject need not be aware of.
Key figures
- Plato
- Edmund Gettier
- Laurence BonJour
- Ernest Sosa
- Earl Conee
- Richard Feldman
Related topics
Seminal works
- gettier1963
- sosa1980
- coneefeldman1985
Frequently asked questions
- Is knowledge just justified true belief?
- The justified-true-belief analysis was the standard view, but Gettier's 1963 counterexamples showed that a belief can be true and justified yet intuitively fail to be knowledge, so most epistemologists now treat JTB as necessary but not sufficient and seek an additional condition.
- What is the regress problem?
- If every justified belief must be justified by another belief, the supporting chain threatens to continue infinitely, loop in a circle, or stop arbitrarily. Foundationalism, coherentism, and infinitism are the three principal responses to this trilemma.