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Scepticism and Descartes' Meditations
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AQA 7172 Paper 1: Descartes' sceptical arguments (dreaming, evil demon), the cogito, clear and distinct ideas and the Cartesian circle, the problem of other minds — with 25-mark essay technique and full mark-scheme answers.
🎯 Learning Objectives
Distinguish normal incredulity from philosophical scepticism and set out Descartes' method of doubt (Spec 3.1.4).
Explain the dreaming and evil demon arguments with their premises and conclusions.
Explain the cogito and Descartes' clear and distinct ideas thesis, including the charge of the Cartesian circle.
Explain the problem of other minds with the argument from analogy and the 'best hypothesis' response (Spec 3.1.4).
Evaluate sceptical arguments and their responses to form reasoned judgements in 25-mark essays (AO2).
Answer 3/5/12-mark questions with pure AO1 explanation, using correct command-word technique.
📋 Key Definitions and Core Concepts
Philosophical scepticism: The claim that we cannot know (or should doubt that we know) some or all of what we ordinarily claim to know — e.g. that there is an external world; a thesis about the limits of knowledge, not ordinary everyday doubt.
Normal incredulity: Everyday doubting that depends on background knowledge and is resolvable by further ordinary evidence ('is the shop shut today?') — unlike philosophical scepticism.
Method of doubt: Descartes' strategy in Meditation 1: withhold assent from any belief that is not indubitable, using the senses-deceive, dreaming and evil demon arguments to strip belief down to a certain foundation.
Dreaming argument: There are no infallible marks distinguishing waking from dreaming, and in dreams we experience things that do not exist; so for any experience we cannot know we are not dreaming — the senses cannot then give knowledge of the external world.
Evil demon (malin génie): Descartes' supposition of a being of supreme power and cunning who systematically deceives him about everything, including mathematics and his own body: if even '2+2=4' could be false, nothing from the senses or from reason is certain.
Cogito: Descartes' indubitable intuition 'I am, I exist' (Meditation 2): necessarily true whenever it is put forward or conceived, since doubting presupposes a thinking 'I'; it establishes the self as a thinking thing (res cogitans).
Clear and distinct ideas: Ideas grasped by the attentive intellect as self-evident (like the cogito); Descartes' truth rule — accept only what is clearly and distinctly perceived — is certified by the proof of a non-deceiving God.
Cartesian circle: The objection (Arnauld) that Descartes relies on clear and distinct ideas to prove God exists, but relies on God (as non-deceiver) to guarantee clear and distinct ideas — the argument is circular.
Problem of other minds: We cannot directly perceive others' minds, only their bodies and behaviour; so how can we know other minds exist at all, or what mental states they contain?
Argument from analogy: Response to the problem of other minds: my mind causes my behaviour; others' bodies and behaviour are relevantly similar to mine; so by analogy their behaviour is probably caused by minds like mine (Mill, Russell).
Res cogitans: 'Thinking thing' — Descartes' conclusion from the cogito: the self is essentially a thinking substance (links to substance dualism in Metaphysics of Mind).
📌 Key Points
Descartes' method of doubt is a search for certainty, not an endorsement of scepticism — sceptical arguments are his tools.
The evil demon is the strongest sceptical scenario because it attacks reason (mathematics) as well as the senses.
The cogito survives all doubt: 'I am, I exist' is necessarily true whenever it is thought.
The Cartesian circle: clear and distinct ideas prove God; God guarantees clear and distinct ideas — Descartes' reply turns on present attention vs memory.
The problem of other minds is answered by the argument from analogy and the 'best hypothesis' response — both inductive, never deductive.
Scepticism and the method of doubt: Meditations 1–2 (Spec 3.1.4)
Two kinds of doubt.Normal incredulity (ordinary incredulity) is everyday doubting that depends on, and is resolved by, further beliefs: 'is the train cancelled?' — check the app. Philosophical scepticism is the claim that we cannot know things we ordinarily take ourselves to know, where no further evidence could settle the matter: e.g. that there is an external world at all. AQA expects the distinction applied, not merely stated — ordinary doubt presupposes we know how to find out; philosophical doubt questions the standards themselves.
Descartes' method of doubt. In Meditation 1 Descartes seeks an unshakeable foundation for knowledge by withholding assent from anything not indubitable. The sceptical arguments — Descartes' three 'waves of doubt' — are demolition tools: (1) the senses sometimes deceive (distant towers look small; things look bent in water) — so it is prudent never to trust completely those who have deceived us even once; (2) the dreaming argument: there are no certain marks by which waking can be distinguished from sleep, and in dreams we seem to perceive things that do not exist — so for any particular experience I cannot know that I am not dreaming, and the senses cannot give knowledge of the external world; (3) the evil demon: suppose a being of supreme power and cunning devotes all his efforts to deceiving me — about my body, the world, and even simple mathematics ('2+2=4'). This is the strongest scenario: it attacks reason as well as the senses, and nothing escapes it.
The cogito (Meditation 2). Even if the demon deceives me about everything else, he cannot deceive me about my doubting: to doubt is to think; to think, I must exist. 'I am, I exist, is necessarily true whenever it is put forward by me or conceived in my mind.' Its certainty is performative — the proposition confirms itself in the very act of being thought. From it Descartes derives that he is a thinking thing (res cogitans): a thing that doubts, understands, affirms, denies, wills, imagines and senses (in the sense of 'having seemings'). Critique: the cogito yields only a momentary certainty — it is true while it is thought; whether the 'I' persists or is a substance needs further argument, and the move from 'there is thinking' to 'I (a continuing substance) exist' is a further inferential step, not part of the intuition itself.
Clear and distinct ideas and the Cartesian circle (Meditations 3–5)
Rebuilding. With one certainty, Descartes generalises: whatever I perceive clearly and distinctly — as the attentive intellect grasps the cogito — is true. But to apply the truth rule beyond the present moment (e.g. to mathematics I am not currently attending to), he must rule out the demon, i.e. prove there is no deceiver. In Meditation 3 he argues from the idea of God: my idea of an infinite, perfect being has more objective reality than a finite mind could supply; by the causal principle (the cause of an idea must have at least as much reality as the idea's content), only God could cause it; a perfect being is non-deceiving (deception is an imperfection); so God exists and guarantees the truth of clear and distinct ideas. Meditation 5's a priori proof (from God's essence — necessary existence) underwrites the same guarantee.
The Cartesian circle. The classic objection (Arnauld): to prove God, Descartes relies on clear and distinct ideas (the causal principle applied to the idea of God); but to trust clear and distinct ideas, he relies on the proved God. The guarantee is bought with the currency it was meant to buy — circular. Descartes' reply: while attending to a clear and distinct idea, its truth is self-evident and needs no guarantee; God is needed only for remembered demonstrations — to secure that the demon cannot sneak back between episodes of attention. Critique: if the guarantee is needed for memory but the proof of God itself relies on remembered premises, the circle reappears; and if self-evidence while attending suffices on its own, God looks redundant.
Why this matters for the exam. The 25-marker on Descartes' epistemology typically turns on this section: know (a) the trademark/causal argument's premises, (b) the truth rule, (c) the circle charge and Descartes' remembered-vs-present reply. Note the connection to scepticism: if the circle is vicious, the evil demon is never ruled out, and Descartes ends where Meditation 1 began — with only the cogito.
The problem of other minds (Spec 3.1.4)
The problem. I know my own mind directly (by introspection); other people's minds I cannot perceive at all — I perceive only bodies and behaviour. Sceptical challenge: how do I know there are other minds at all (rather than automata), or what others feel? The stakes are high: testimony, language and most of our knowledge presuppose other thinkers.
Argument from analogy. (Mill, Russell.) (1) I know by introspection that my mental states cause my bodily behaviour (I feel embarrassed; I blush). (2) Other bodies are relevantly similar to mine, and their behaviour is similar. (3) The best explanation of similar behaviour in similar bodies is that it is caused by mental states like mine. Conclusion: probably, other minds exist. Critique: the analogy is a single-case induction — one mind (mine) is a tiny sample; and the reasoning is inductive, so at most probable, never certain — it cannot answer the philosopher's sceptic who demands deductive proof.
Best hypothesis response. The existence of other minds is the best explanation of the complexity, purposiveness and linguistic creativity of others' behaviour: treating people as thinkers explains and predicts their conduct far better than any automaton hypothesis. Critique: same epistemic ceiling — inference to the best explanation is still inductive; and the automaton hypothesis is not clearly worse, since a sufficiently complex machine would behave indistinguishably.
Connections. In Meditation 6 Descartes argues that I have a 'great inclination' to believe my sensations come from bodies existing independently of me, divinely guaranteed; but other minds are not so guaranteed. Note also the dualist link: if minds are non-extended substances (Metaphysics of Mind), the epistemic gap between my mind and other minds is wider still — dualism intensifies the problem. Examiner tip: 12-markers here ask you to explain the problem and one response — premises, conclusion, response, and stop.
Responses to scepticism and its limits (Spec 3.1.4)
Reliabilism as a response. If knowledge is true belief produced by a reliable process rather than belief that is internally demonstrable, the sceptic's demand for indubitability is misplaced. My perceptual beliefs are formed by reliable processes in normal conditions; that I cannot rule out dreaming or demons does not show those processes are unreliable. Critique: reliabilism concedes that I cannot tell whether I know — an externalist cost ('I know, but I could not say why'); and in abnormal conditions the same internal evidence would be misleading, so the intuition that knowledge must be certain fights back.
Localising scepticism. A further response: philosophical scepticism is idle — it questions everything at once and so cannot be acted on; ordinary inquiry proceeds by ordinary standards. The Moore-style 'here is a hand' proof is the classic gesture: if the proof fails, the sceptic's premises ('I cannot rule out that I am dreaming') are less certain than the conclusion they deny ('I am not dreaming') — a pragmatic asymmetry that weakens the sceptic's case. For AQA the evaluative point is: the sceptic's premises must be more certain than the ordinary beliefs they overthrow, and it is not obvious that they are.
What survives. Even the harshest assessment leaves: (1) the cogito — the one proposition that defeats the demon by being thought; (2) the a priori/a posteriori structure of what is under attack — the demon attacks a posteriori beliefs via dreaming and a priori beliefs via false mathematics; (3) the insight that perception and knowledge of other minds are never demonstrative. A* answers connect these: scepticism is defeated only if either the cogito generalises (Descartes' route) or the standard for knowledge drops from certainty to reliability (reliabilist route) — and each route has a named cost (the circle; the externalist opacity).
Exam technique: AQA 7172 scepticism (Paper 1, Section A)
Where it lands. Scepticism sits in Epistemology (Spec 3.1.4, 'The limits of knowledge') on Paper 1 Section A: five questions worth 3, 5, 5, 12 and 25 marks. Short questions are pure AO1; the 25-marker (5 AO1 + 20 AO2) presents a quoted claim + 'Evaluate this claim'.
25-mark essay structure. Introduction: define philosophical scepticism, state your thesis. Then argue with intent — e.g. that Descartes' sceptical arguments fail to establish global scepticism: (1) argument for the thesis: the cogito survives all doubt, and the dreaming argument only localises doubt to particular experiences; consider the best objection: the evil demon attacks mathematics too, so the cogito is the only survivor; respond. (2) Argument against the thesis: the Cartesian circle means God never guarantees clear and distinct ideas, so the demon is never ruled out; weak response, then strong response. Conclusion consistent with the introduction, no new ideas. Mark scheme top band (21–25): 'crucial arguments clearly identified against less crucial ones' — develop the demon and the circle in depth; the senses-deceive argument is less crucial and can be one line.
Common pitfalls and examiner tips (click to expand)
Method ≠ creed: Descartes uses sceptical arguments to find certainty — answers that treat him as a sceptic miss the point; describe the method of doubt as a tool.
The cogito is conditional: 'I am, I exist' is necessarily true whenever it is thought — do not claim it proves an enduring soul by itself.
Cartesian circle: state both halves (clear and distinct ideas prove God; God guarantees clear and distinct ideas), then Descartes' remembered-vs-present reply, before evaluating.
Other minds ≠ mind–body problem: the problem of other minds is epistemic (how do I know?); do not swap it for interactionism.
Command words: 'Explain the dreaming argument' (12 marks) = premises + conclusion + response only; writing 'but Descartes replies that scepticism is false…' here loses marks for redundancy.
Timing: ~35–40 minutes per 25-marker, ~15 for the 12-marker; leave five minutes to check the conclusion matches the introduction.
💡 Worked Example
Exam-style: 'Descartes' sceptical arguments show we cannot know anything beyond our own minds.' Evaluate this claim. (25 marks)
Mark-scheme logic: AO1 required: set out the method of doubt, the dreaming argument (no infallible marks; dreams present non-existent things; so the senses cannot give knowledge of the external world), the evil demon (supreme deceiver attacks mathematics as well as the senses), the cogito ('I am, I exist' — necessarily true whenever thought), the clear and distinct ideas truth rule, and the Cartesian circle charge. AO2 — argue with intent, e.g. AGAINST the claim: (1) the cogito defeats the demon: doubting presupposes thinking, so 'I am, I exist' is indubitable — knowledge beyond doubt survives, though only about my own mind at the moment of thought; (2) the dreaming argument localises: it removes knowledge of particular external objects at particular times, not all knowledge. Consider the strongest objection FOR the claim: the evil demon attacks even a priori beliefs, and the Cartesian circle means God never certifies clear and distinct ideas — so nothing beyond the cogito is secure. Respond: Descartes' remembered-vs-present distinction blocks the circle (self-evidence needs no guarantee while attending; God secures memory), and if that fails, the reliabilist route still leaves fallible knowledge of the world. Weigh up and conclude consistently (e.g. the claim overstates: global scepticism is not established, but knowledge beyond one's own mind does require rejecting Descartes' standard of certainty).
❓ Practice Questions & Mark Schemes
Explain the difference between ordinary incredulity and philosophical scepticism. (5 marks)
Answer: AO1 only — no evaluation. Ordinary incredulity is everyday doubting that depends on and is resolved by further beliefs or evidence: doubting whether the shop is shut today is settled by walking there; it presupposes that we know how to find things out. Philosophical scepticism is the thesis that we cannot know things we ordinarily claim to know — e.g. that there is an external world — where the doubt cannot be resolved by any further evidence, because the doubt questions the evidential standards themselves.
Explain Descartes' dreaming argument and one response. (12 marks)
Answer: AO1 only. Set out the premises: (1) there are no certain marks by which waking experience can be distinguished from dreams; (2) in dreams we have experiences that seem to perceive things which do not exist; (3) for any current experience, I cannot know that I am not dreaming. Conclusion: since dream-experiences are of non-existent objects and I cannot rule out that I am dreaming, my senses cannot give me knowledge of the external world — at most I can know general truths (Descartes: arithmetic and geometry survive dreaming). Explain one response: the localised-doubt response — the argument removes knowledge of particular objects at particular times (I cannot know I am not dreaming now), but general truths and the general existence of extended things survive; so the argument does not establish global scepticism. State the conclusion: the dreaming argument overreaches if read as establishing that nothing is known.
Explain the problem of other minds and the argument from analogy. (12 marks)
Answer: AO1 only. The problem: I know my own mind by direct introspection, but I cannot perceive other people's minds — only their bodies and behaviour; so how can I know that other minds exist (rather than automata), or what mental states they have? The stakes: testimony, language and most of our knowledge presuppose other thinkers. The argument from analogy (Mill, Russell): (1) by introspection I know that my mental states cause my behaviour (I feel pain; I wince); (2) others' bodies and behaviour are relevantly similar to mine; (3) the best explanation of similar behaviour in similar bodies is that it is caused by similar mental states. Conclusion: probably, other minds exist and their mental states resemble mine.
Explain Descartes' cogito. (5 marks)
Answer: AO1 only. In Meditation 2, even under the supposition of an evil demon who deceives him about everything else, Descartes finds one indubitable truth: 'I am, I exist, is necessarily true whenever it is put forward by me or conceived in my mind.' Doubting presupposes a thinking 'I' — the attempt to doubt the cogito confirms it, since to doubt is to think. From it Descartes concludes that he is a thinking thing (res cogitans): a thing that doubts, understands, affirms, denies, wills, imagines and senses.
'The argument from analogy successfully answers the problem of other minds.' Evaluate this claim. (25 marks)
Answer: AO1 required: set out the problem (other minds are never perceived, only bodies and behaviour) and the argument from analogy: my mind causes my behaviour; others' bodies and behaviour are relevantly similar to mine; so probably their behaviour is caused by minds like mine (Mill, Russell). AO2 — argue with intent, e.g. FOR the claim: (1) the analogy mirrors inductive inferences licensed elsewhere (from observed to unobserved cases, as in science); (2) it uses only what we actually know — introspection plus observation of behaviour. Consider the strongest objection AGAINST: it is a single-case induction — one mind (my own) is too small a sample to license inference to all other minds; and it yields only probability, so it cannot satisfy the philosophical sceptic who demands deductive proof. Respond: demanding deductive proof sets too high a standard — every empirical inference is probabilistic, and the 'best hypothesis' variant (other minds best explain complex, creative, linguistic behaviour) strengthens the inductive base. Counter-response: a sufficiently sophisticated automaton hypothesis would explain the same behaviour, so the inference still underdetermines. Weigh up and conclude consistently (e.g. the claim is only partly successful: analogy gives strong practical reason to believe in other minds, but cannot answer the philosopher's sceptic demanding certainty).
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