What is the Moorean response in a nutshell?

Moore holds up his hands and argues that he knows he has hands, that this entails an external world exists, and therefore that an external world exists. Since his knowledge of his hands is more certain than any premise the skeptic offers, he treats the skeptical argument as a reason to doubt one of its own premises.

How does contextualism reconcile skepticism with common sense?

It holds that how much one must be able to rule out to count as 'knowing' varies with context. In everyday talk the standards are low, so we know ordinary things; once the skeptic raises far-fetched possibilities the standards rise and the same sentences become false, so neither party need be simply mistaken.

Responses to Skepticism

Philosophers have answered the skeptic in strikingly different ways: by insisting that ordinary knowledge is more certain than any skeptical premise, by holding that 'knows' shifts its standards with context, and by restricting which alternatives a knower must rule out.

Definition

Responses to skepticism are the philosophical strategies for resisting the conclusion that we lack knowledge of the external world, ranging from rejecting a premise of the skeptical argument to reinterpreting the standards governing knowledge claims.

Scope

This topic surveys the main anti-skeptical strategies that accept the closure principle: the Moorean reversal of the skeptical argument, contextualism about knowledge attributions, and the relevant-alternatives theory. It contrasts these with the closure-denying response treated elsewhere and notes the dissolving and diagnostic approaches that question whether the skeptical problem is well posed. The construction of the skeptical argument itself is covered in companion topics.

Core questions

Can the skeptical argument be turned on its head by treating ordinary knowledge as a fixed point?
Does the truth of a knowledge claim depend on the conversational context?
Need a knower rule out only the relevant alternatives rather than every conceivable one?
Do anti-skeptical strategies answer the skeptic or merely change the subject?

Key theories

Moorean response: Moore reverses the skeptical argument: he treats his knowledge that here is a hand as more certain than any skeptical premise, so that the existence of an external world is better supported than the doubts marshalled against it.
Contextualism: DeRose argues that the word 'knows' is context-sensitive: in ordinary contexts the standards are low enough that we count as knowing everyday facts, while raising skeptical possibilities lifts the standards, so both the skeptic and common sense can be right relative to their contexts.
Relevant alternatives: On the relevant-alternatives theory, to know p one need only rule out the alternatives that are relevant in the situation, not far-fetched skeptical scenarios, so ordinary knowledge survives even though the brain-in-a-vat hypothesis goes unaddressed.

History

Moore's 1939 commonsense proof set the template for treating ordinary knowledge as more secure than skeptical doubt. The relevant-alternatives theory grew from Dretske's work, and in 1995 DeRose's contextualism offered a linguistically grounded reconciliation of skeptical and everyday verdicts. Throughout, Stroud pressed the worry that such replies may fail to satisfy the skeptic on the skeptic's own terms.

Debates

Do anti-skeptical strategies beg the question?: Stroud and others argue that Moorean and contextualist responses presuppose what the skeptic challenges or merely describe our practices rather than vindicating them, while their defenders reply that demanding a non-question-begging refutation concedes too much to the skeptic.

Key figures

G. E. Moore
Keith DeRose
Fred Dretske
Barry Stroud

Seminal works

moore1939
derose1995

Frequently asked questions

What is the Moorean response in a nutshell?: Moore holds up his hands and argues that he knows he has hands, that this entails an external world exists, and therefore that an external world exists. Since his knowledge of his hands is more certain than any premise the skeptic offers, he treats the skeptical argument as a reason to doubt one of its own premises.
How does contextualism reconcile skepticism with common sense?: It holds that how much one must be able to rule out to count as 'knowing' varies with context. In everyday talk the standards are low, so we know ordinary things; once the skeptic raises far-fetched possibilities the standards rise and the same sentences become false, so neither party need be simply mistaken.