What is knowledge? — AQA A-Level Philosophy
Teaching note based on the AQA specification.
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What is knowledge? explained
What is knowledge? covers 8 specification points, including The distinction between acquaintance… and The nature of definition (including Linda….
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Open a point below for its explanation and revision guidance.
The distinction between acquaintance knowledge, ability knowledge and propositional knowledge.
Philosophers sort knowledge into three kinds. Acquaintance knowledge is knowing a thing or person by direct familiarity: you know the taste of a lemon, or you know a friend, rather than knowing facts about them. Ability knowledge is knowing how to do something, such as riding a bicycle or speaking French; it is shown in successful performance and need not be expressible in words. Propositional knowledge is knowing that something is the case, expressed in a that-clause: that water boils at 100 °C at sea level. The distinction matters because epistemology's standard target is propositional knowledge, yet the other kinds resist analysis in the same way. A useful test is to ask what completes the sentence: 'knows how to…' signals ability, 'knows that…' signals proposition, and 'knows X itself' (a place, person, taste) signals acquaintance.
The nature of definition (including Linda Zagzebski) and how propositional knowledge may be analysed/defined.
This topic asks what it is to give a definition and how propositional knowledge might be defined. A definition specifies necessary and sufficient conditions: a condition is necessary if nothing can be the thing without it, and sufficient if meeting it guarantees being the thing. Analysis aims to break a concept into such conditions, as the tripartite account does by defining knowledge as justified true belief. Linda Zagzebski's work on the nature of definition is used to examine what definitions do and their limits, including whether a concept can be captured by a neat set of conditions or whether definitions are better understood through paradigm cases and resemblance. The topic connects directly to later material: if knowledge is justified true belief, Gettier-style cases test whether those conditions are genuinely sufficient.
The tripartite view: Propositional knowledge is defined as justified true belief: S knows that p if and only if: 1. S is justified in believing that p, 2. p is true and 3. S believes that p (individually necessary and jointly sufficient conditions)
The tripartite view analyses propositional knowledge — knowledge that some claim p is the case, as opposed to knowing how to do something or being acquainted with a person. It states that S knows that p if and only if three conditions hold: S believes that p; p is true; and S is justified in believing that p. Each condition is claimed to be individually necessary, so removing any one means there is no knowledge: a lucky true guess lacks justification, a justified false belief lacks truth, and a justified true state of affairs nobody believes is not knowledge for anyone. Together the three are claimed to be jointly sufficient, so whenever all hold there is knowledge. Test this with a case: a student believes the exam is on Tuesday, has checked the timetable, and it is on Tuesday — all three conditions appear met.
the conditions are not individually necessary
This claim is a challenge to the tripartite view: it denies that belief, truth and justification are each required for knowledge. The challenge works by producing a case where someone knows that p even though one of the supposed conditions is absent. If such a case succeeds, that condition is not necessary, and the 'if and only if' definition fails. A learner should be able to explain what 'not individually necessary' means — at least one condition can be missing while knowledge remains — and to assess whether a proposed counterexample really is knowledge. Note the difference between attacking necessity (a condition can be absent) and attacking sufficiency (all conditions present but no knowledge, as in Gettier-style cases). Keep the two challenges distinct when answering.
the conditions are not sufficient – cases of lucky true beliefs (including Edmund Gettier’s original two counter examples): responses: alternative post-Gettier analyses/definitions of knowledge including: strengthen the justification condition (ie infallibilism)
The tripartite analysis says knowledge is justified true belief (JTB). Gettier's two original counter examples aim to show these conditions are not sufficient: a belief can be justified and true yet true only by luck. In the first, Smith has strong evidence that Jones will get the job and that Jones has ten coins in his pocket, so he infers that the person who will get the job has ten coins in his pocket; unknown to Smith, he himself gets the job and also has ten coins, making the belief true but only by luck. In the second, Smith justifiably believes a disjunction such as 'Jones owns a Ford or Brown is in Barcelona', based on strong evidence for the first disjunct; unknown to Smith, Jones does not own a Ford but Brown happens to be in Barcelona, so the belief is true by luck.
add a 'no false lemmas' condition (J+T+B+N)
The 'no false lemmas' condition responds to Gettier-style cases for the tripartite account of knowledge as justified true belief. A lemma is an intermediate belief used to reach the target belief. The added condition N states that the subject's belief must not be inferred through any false lemma. So knowledge is analysed as justified, true belief that is not essentially dependent on a false step (J+T+B+N). In a typical Gettier case, the subject forms a true belief by inferring from a justified but false belief; adding N blocks that case because the route to the belief passes through a falsehood. Learners should be able to state the condition precisely, apply it to a described case by tracing the inferential route, and note the limitation that some Gettier-style cases appear to involve no false lemma, so the condition may not capture every counterexample.
replace 'justified' with 'reliably formed' (R+T+B) (ie reliabilism)
This row asks you to work with a reliabilist revision of the tripartite analysis: knowledge is true belief that is reliably formed, rather than true belief that is justified. The three conditions become belief, truth and reliable formation (R+T+B). Reliabilism holds that a belief counts as knowledge when it is produced by a cognitive process that generally yields true beliefs, such as perception, memory or sound reasoning, even if the believer cannot articulate a justification. So the task is to identify which option correctly swaps the justification condition for reliable formation while keeping the belief and truth conditions intact. A concrete case: a child reliably recognises her mother's face without being able to justify how, and reliabilism treats this as knowledge. Distinguish this from simply adding a fourth condition or dropping truth.
replace 'justified' with an account of epistemic virtue (V+T+B).
This option tests virtue epistemology as a revision of the tripartite analysis. Instead of requiring justification, virtue accounts require that the true belief arise from the exercise of epistemic virtue, giving V+T+B. Epistemic virtues are good intellectual traits or competences, such as careful observation, open-mindedness, intellectual courage or reliable perceptual and reasoning abilities, depending on the version. The belief must be true and held, and it must be creditable to the agent's virtuous cognitive activity rather than to luck. In an MCQ, select the option that names epistemic virtue as the replacement for justification while retaining truth and belief, and reject options that keep justification or substitute mere reliability of process.
Your focus
- Classify given examples as acquaintance, ability or propositional knowledge.
- Explain the criterion that distinguishes the three kinds.
- Justify why propositional knowledge is central to epistemology.
Show all 24 objectives
- Explain necessary and sufficient conditions with examples.
- Apply the tripartite definition to test cases.
- Evaluate the limits of defining knowledge by conditions.
- State the tripartite definition of propositional knowledge using belief, truth and justification.
- Explain what it means for the three conditions to be individually necessary and jointly sufficient.
- Apply the definition to a case to identify which condition fails.
- Explain what it means to deny that the three conditions are individually necessary.
- Distinguish challenges to necessity from challenges to sufficiency.
- Evaluate a counterexample offered against the tripartite definition.
- Explain how Gettier's two counter examples challenge the sufficiency of JTB.
- Reconstruct the details of each counter example accurately.
- Explain how infallibilism strengthens the justification condition in response.
- State the no false lemmas condition and explain what a lemma is in this context.
- Apply J+T+B+N to a described case by tracing the inferential route to the belief.
- Evaluate whether the condition excludes all Gettier-style counterexamples.
- State the reliabilist formula for knowledge as belief, truth and reliable formation.
- Distinguish reliable formation from justification in the tripartite analysis.
- Select the option that correctly substitutes the third condition without altering belief or truth.
- State the virtue-epistemological formula V+T+B.
- Explain what counts as an epistemic virtue.
- Distinguish virtue epistemology from reliabilism and from JTB.
What is knowledge? flashcards
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Reliabilism
What is knowledge? exam tips
Marking Points
- Acquaintance knowledge is knowledge of a thing or person by direct familiarity or experience, not knowledge of facts about it.
- Ability knowledge is knowing how to perform a skill, demonstrated in doing it, and need not be verbally articulable.
- Propositional knowledge is knowledge that a proposition is true, expressed in a 'that'-clause.
- The three are distinguished by the grammatical form of what is known: an object, a skill, or a fact.
- Recognising that epistemology's central concern is propositional knowledge, while the other kinds are not straightforwardly analysable in the same terms.
- A definition states necessary and sufficient conditions for applying a term.
- A necessary condition must hold for the thing to count; a sufficient condition guarantees the thing counts.
- Analysing propositional knowledge traditionally yields the tripartite definition: justified true belief.
- Linda Zagzebski's account of definition is used to examine what definitions aim to do and their limitations.
- The adequacy of the tripartite definition is tested by whether its conditions are jointly sufficient, motivating Gettier cases.
- Identifies the three conditions as belief, truth and justification, and states that knowledge requires all three.
- Explains 'individually necessary': each condition must hold, and if any one fails the agent lacks knowledge.
- Explains 'jointly sufficient': when all three conditions are satisfied together, that is claimed to be enough for knowledge.
- Applies the analysis to a case, showing which condition fails in a lucky guess (justification), a false but justified belief (truth) or an unheld truth (belief).
- Recognises that the 'if and only if' formulation makes the definition a claimed exact equivalence, not merely a list of typical features.
- Explains that 'not individually necessary' means at least one of belief, truth or justification can be absent while knowledge still occurs.
- Distinguishes a challenge to necessity from a challenge to sufficiency, which concerns cases where all three conditions hold but knowledge is absent.
- Assesses a candidate counterexample, asking whether the agent genuinely knows and which condition is allegedly missing.
- Explains the consequence for the tripartite definition: if a condition is not necessary, the 'if and only if' claim is false.
- The tripartite analysis defines knowledge as justified true belief, and Gettier cases challenge the sufficiency of these three conditions.
- First counter example: Smith justifiably infers from strong evidence about Jones (he will get the job; he has ten coins) that the person who will get the job has ten coins in his pocket; Smith himself gets the job and has ten coins, so the belief is true but only by luck.
- Second counter example: Smith justifiably believes a disjunction ('Jones owns a Ford or Brown is in Barcelona') on strong evidence for the first disjunct; Jones does not own a Ford but Brown is in Barcelona, so the belief is true by luck.
- Infallibilism strengthens the justification condition by requiring justification that guarantees the truth of the belief, closing the lucky-truth gap.
- The general lesson is that justification plus truth can still fall short of knowledge when the truth is accidental relative to the justification.
- States the no false lemmas condition: the belief must not be reached by inference through any false intermediate belief (lemma).
- Explains the role of a lemma as an intermediate belief used to derive the target belief, distinguishing it from the final belief itself.
- Applies J+T+B+N to a Gettier-style case by tracing the inferential route and identifying whether a false lemma is involved.
- Explains how the N condition blocks cases where a justified true belief is inferred from a justified but false belief.
- Identifies a limitation: some purported Gettier-style cases seem to involve no false lemma, so the condition may not exclude every counterexample.
- Identifies that the justification condition is replaced by a reliable-formation condition, giving belief, truth and reliable formation (R+T+B).
- Explains that reliability concerns the process producing the belief generally tending to yield true beliefs, not the believer's ability to state reasons.
- Keeps the belief and truth conditions unchanged; the revision targets only the third condition.
- Recognises that reliabilism is an externalist account: the reliability need not be accessible to the believer.
- Rejects options that drop truth, drop belief, or merely add a fourth condition rather than substituting the third.
- Identifies virtue epistemology as replacing justification with the exercise of epistemic virtue, giving V+T+B.
- States that truth and belief conditions are retained.
- Explains that epistemic virtues are good intellectual traits or competences of the knower.
- Distinguishes knowledge creditable to virtuous cognitive activity from a true belief produced by luck.
- Rejects options that retain justification or that describe only reliable processes without reference to the agent's virtues.
Examiner Tips
- 💡Use the 'knows that / knows how to / knows X itself' test to classify examples quickly.
- 💡Give a concrete example for each kind rather than only defining them.
- 💡When asked to distinguish, state the criterion of difference (object, skill or fact) explicitly.
- 💡Define 'necessary' and 'sufficient' precisely before applying them.
- 💡Use a counterexample to test whether proposed conditions are sufficient.
- 💡Link the nature of definition to the tripartite account and to Gettier cases.
- 💡Learn the definition in the 'if and only if' form so you can state necessity and sufficiency precisely.
- 💡For each condition, prepare one short counterexample showing what is lost when it fails.
- 💡Use a single running example and vary one condition at a time to show the analysis at work.
- 💡Label each challenge clearly as targeting necessity or sufficiency before evaluating it.
- 💡When using a counterexample, state explicitly which condition is absent and why knowledge remains.
- 💡Consider a possible reply defending the tripartite view, then judge which side is stronger.
- 💡State each Gettier case with its key details (the evidence, the inference and the unexpected truth-maker) before drawing the conclusion.
- 💡Make explicit that the argument concerns sufficiency, not necessity, of the JTB conditions.
- 💡When explaining infallibilism, say what it adds — a guarantee of truth — and note the cost of making knowledge very hard to attain.
- 💡When applying the condition, write out the inferential chain explicitly so the intermediate lemma is visible.
- 💡State the condition in full before applying it, so the examiner can see the analysis rather than only a verdict.
- 💡Distinguish clearly between the truth of the final belief and the truth of the lemma used to reach it.
- 💡If evaluating, consider a case with no false lemma and explain what that implies for the adequacy of the condition.
- 💡Underline the three letters R+T+B and check each option preserves belief and truth while swapping justification for reliability.
- 💡Ask of each option whether the reliability is a feature of the process or a feature of the believer's reasons; reliabilism concerns the process.
- 💡Eliminate options that change more than one condition, since the row specifies replacing only 'justified'.
- 💡Use a quick example such as reliable face recognition to test whether an option captures external reliability.
- 💡Check that the chosen option keeps truth and belief before assessing the third condition.
- 💡Look for wording about the agent's intellectual character or competences.
- 💡Eliminate options that describe justification or mere process reliability when virtue is required.
Common Mistakes
- Treating ability knowledge as just a set of propositional facts; correction: knowing how to swim is shown in performance and is not exhausted by knowing facts about swimming.
- Confusing acquaintance knowledge with propositional knowledge about a person; correction: knowing a friend directly differs from knowing facts about them.
- Assuming all knowledge must be expressible as a 'that'-clause; correction: acquaintance and ability knowledge resist that form.
- Confusing necessary and sufficient conditions; correction: necessary means cannot be absent, sufficient means its presence guarantees the thing.
- Treating the tripartite account as obviously correct; correction: it is a proposed analysis whose sufficiency is contested.
- Reducing Zagzebski's contribution to a single slogan; correction: engage with her account of what definitions are for and their limits.
- Treating the three conditions as a checklist where two out of three will do; the correction is that each is claimed necessary, so all must hold.
- Confusing justification with truth, assuming a well-supported belief must be true; the correction is that a justified belief can still be false, and then it is not knowledge.
- Thinking the tripartite view is obviously correct; the correction is that it is a contested definition, and later material examines whether the conditions are sufficient.
- Describing knowledge-how or acquaintance as the target; the correction is that the tripartite analysis concerns propositional knowledge, knowledge that p.
- Confusing 'not necessary' with 'not sufficient'; the correction is that necessity concerns a missing condition, sufficiency concerns all conditions present without knowledge.
- Assuming any odd case disproves the definition without checking that knowledge is genuinely present; the correction is to justify that the agent knows.
- Thinking the claim asserts that none of the conditions is ever needed; the correction is that it denies individual necessity, which may affect only one condition.
- Treating the claim as settled fact rather than a position to be assessed with argument and examples.
- Describing Gettier cases as showing JTB is unnecessary: correction — they target sufficiency, showing JTB can occur without knowledge.
- Getting the details of the first case wrong, for example omitting that Smith himself ends up with the job and the coins: correction — the luck arises precisely because the truth-maker differs from what Smith's evidence supported.
- Treating infallibilism as simply 'more justification': correction — infallibilism requires justification that guarantees truth, not merely stronger evidence.
- Treating N as requiring that all of the subject's beliefs be true; correction: N concerns only the inferential route to the target belief, not the whole belief set.
- Confusing the false lemma with the final belief; correction: the lemma is an intermediate belief from which the target belief is inferred, and it is that intermediate step that must not be false.
- Assuming J+T+B+N settles the Gettier problem completely; correction: it addresses cases involving false lemmas but may leave other counterexamples unaddressed.
- Treating reliabilism as adding a fourth condition on top of justification; the correction is that reliable formation replaces justification.
- Assuming the believer must be able to state the reliable process; the correction is that reliability can be external to the believer's awareness.
- Confusing reliability with infallibility; the correction is that a reliable process generally produces true beliefs but need not guarantee them every time.
- Dropping the truth condition; the correction is that reliabilism still requires the belief to be true.
- Treating virtue epistemology as adding virtue to JTB rather than replacing justification; correct this by stating it is V+T+B.
- Confusing epistemic virtue with moral virtue; correct this by focusing on intellectual traits such as carefulness and open-mindedness.
- Assuming any true belief displays virtue; correct this by requiring the belief to be creditable to the agent's virtuous activity.