Questions: Moore's Methods and Responses to Skepticism

Question 1

A philosopher presents this valid argument: (1) You cannot rule out being a brain in a vat. (2) If you cannot rule out being a brain in a vat, you cannot know you have hands. (3) Therefore, you do not know you have hands. A Moorean response would most likely:

• A. Accept the conclusion and seek comfort in the fact that we act as if we have hands even without knowledge
• B. Deny the argument is valid and show that premises (1) and (2) do not logically entail (3)
• C. Run the argument in reverse: 'I know I have hands' gives stronger grounds to deny premise (1) or (2) than the skeptical premises give to accept (3)
• D. Argue that brains in vats cannot have genuine beliefs, so the skeptical scenario is self-defeating

Answer: (C)

The Moorean move — 'tollensing the ponens' — runs the argument backwards. Instead of: P1, P2 → ¬Knowledge, Moore says: Knowledge, P2 → ¬P1. Which direction you run the argument depends on which you trust more: the skeptical premises, or your ordinary perceptual knowledge. Moore's claim is that 'I know I have hands' has higher epistemic standing than any abstract philosophical premise, so the monstrous conclusion (no knowledge of hands) gives us grounds to reject a premise.

Question 2

Nozick's tracking theory supports denying closure in response to skepticism. Which best states the key claim?

• A. You know 'I have hands' because this belief is justified by coherent sensory experience, but justification doesn't extend to skeptical scenarios
• B. You know 'I have hands' because your belief tracks the truth — you believe it when true and wouldn't if false — but you cannot track 'I am not a brain in a vat' because in that scenario you'd still believe you're not
• C. You know 'I have hands' because the probability of being a brain in a vat is negligibly small
• D. You know 'I have hands' because ordinary language doesn't require ruling out remote possibilities like brains in vats

Answer: (B)

Nozick's tracking theory: you know P if your belief tracks its truth — you believe it when true, and wouldn't believe it if it were false. You track 'I have hands' perfectly: if you didn't have hands, your experience would be different. But 'I am not a brain in a vat' fails: if you were a brain in a vat, you'd still believe you're not. So you don't know this — without that undermining your hand knowledge. This is how closure fails: knowledge doesn't transmit across all known entailments.

Question 3

Moore's response to skepticism is simply an appeal to common sense — he says 'I just know I have hands' without providing any philosophical reasoning.

• T. True
• F. False

Answer: False

This is a common misreading. Moore's position uses a genuine philosophical argument structure: he runs the skeptical argument in reverse (tollensing the ponens) and makes the substantive epistemological claim that ordinary knowledge has higher epistemic standing than abstract philosophical premises. As the Common Misconceptions note: 'Moore's position isn't a simple appeal to intuition; it uses inference to the best explanation about which principles to trust.'

Question 4

According to contextualism, both the skeptic and Moore can be correct — each is making a knowledge claim that is true relative to different conversational standards.

• T. True
• F. False

Answer: True

Contextualism holds that standards for 'knowing' vary with conversational context. In everyday life, relevant alternatives to 'I have hands' are things like bandages or prostheses — easily ruled out. In a philosophy seminar where brains-in-vats are explicitly under discussion, those remote alternatives become relevant, raising the standards. On this view, 'I know I have hands' is true in the ordinary context and potentially false in the philosophical context — neither speaker is simply wrong.

Question 5

Explain what 'tollensing the ponens' means in the context of Moore's response to skepticism, and why it is a philosophically legitimate move rather than a logical error.

Model answer: Tollensing the ponens means running a modus ponens argument backwards as modus tollens. The skeptic argues: P1, P2, therefore ¬K. Moore argues: K, P2, therefore ¬P1. Both are valid argument forms. Which direction to run the argument depends on which premise you have stronger reason to accept. Moore's claim is that 'I know I have hands' (K) has higher epistemic standing than the skeptic's abstract premise P1 — so the obviously false conclusion is grounds to reject the premise.

Logical validity is symmetric: if an argument is valid, both modus ponens and modus tollens are valid inferences from the same premises. A valid argument whose conclusion seems obviously false provides evidence against one of its premises — this is how mathematics works too (reductio ad absurdum). Moore applies this same logic to skepticism: the monstrous conclusion that I don't know I have hands is evidence against a premise, not an invitation to accept the monstrosity.