Key Idea: Topic 3.2 stress-tests knowledge. Once you know what knowing IS (3.1), the hard question is whether we ever really have it — the sceptic, Gettier, and the puzzle of perception all attack the same weak spot: justification. This optional theme is examined in Paper 1 Section B — a 25-mark 'Evaluate the claim that…' essay. These problems are the objections you'll weigh in it.
🧠 The four big problems, one card each
Topic 3.2 at a glance
- 3.2.1 · Scepticism — Descartes doubts everything on purpose: the dream (doubt the senses) then the evil demon (doubt even maths). One thing survives — 'I think, therefore I am': a thinker must exist to be deceived. The deep question: does knowledge really need certainty, or just strong reasons?
- 3.2.2 · The Gettier problem — The stopped-clock case shows you can tick every box — belief, truth, justification — and still be right only by luck, which isn't knowledge. JTB is necessary but not sufficient; the missing ingredient is roughly 'no luck', but there's no agreed way to define it.
- 3.2.3 · Theories of perception — When appearances can differ from reality, what do you actually see? Direct realism (the world itself), representative realism (mental images of a real world — stuck behind a 'screen'), or idealism (only images, no material world — Berkeley, but the world then needs God).
- 3.2.4 · Justification — Every reason needs a reason — the regress — so justification must end somehow or the sceptic wins. Foundationalism stops at basic beliefs; coherentism loops into a supporting web; reliabilism says a reliable process justifies, no chain of stated reasons needed (and answers Gettier).
The Gettier problem: justified true belief is not enough. You can believe something, have good reasons, and be right — yet still only be right by luck, so it isn't knowledge. This is the crack that runs through the whole topic: the sceptic doubts justification can ever be secure, and reliabilism was invented to patch exactly this luck-shaped hole. Whenever you see 'knowledge', ask: is the justification actually connecting the belief to the truth, or is it luck?
✍️ Bring it together — a Section B question
Evaluate the claim that knowledge requires certainty.
Model answer plan
See the mark-by-mark plan — for / against / judgement, with marking guidance — in study mode.
Important: Retelling the problems instead of evaluating the claim. Section B is not 'describe scepticism and Gettier' — it is 'is THIS claim true?' Every paragraph must move the claim forward: argue for it, hit it with the strongest objection, then judge. A famous case like the evil demon or the stopped clock earns marks only when it does work ON the claim — and a top answer always ends on a reasoned conclusion, never 'it's just opinion'.
✅ Check yourself
If you can answer these six, you have the spine of the whole topic.
What is Descartes' method of doubt? Doubt everything on purpose: the dream (doubt the senses), then the evil demon (doubt even maths), to find what survives.
What does the cogito establish? 'I think, therefore I am' — a thinker must exist to be deceived, so your own existence is one thing you can't doubt.
What does the Gettier problem show? You can tick belief, truth AND justification and still be right only by luck — so JTB is necessary but not sufficient for knowledge.
Name the three theories of perception. Direct realism (you see the world itself), representative realism (you see images OF a real world), idealism (only images, no material world).
What is the regress of justification? Every reason needs a further reason, so the chain must end somehow — or the sceptic wins.
Foundationalism vs coherentism vs reliabilism? Foundationalism stops at basic beliefs; coherentism loops into a supporting web; reliabilism says a reliable process justifies, no stated chain needed.
Exam tips
- Section B is a 25-mark 'Evaluate the claim that…' essay with NO stimulus — the claim itself is your whole starting point.
- Evaluate, don't retell: argue for the claim, then against it, then weigh and conclude.
- Use a named case (evil demon, stopped clock) only to move the claim forward — never as decoration.
- Let Gettier and reliabilism deepen the discussion: the real target is often reliability, not certainty.