Here Is A Hand - Introduction

Introduction

G. E. Moore (1873—1958) wrote A Defence of Common Sense and Proof of an External World. He posed skeptical hypotheses, such as "you may be dreaming" or "the world is 5 minutes old", creating a situation where it is not possible to know that anything in the world exists. These hypotheses take the following form:

The skeptical argument

Where S is a subject, sp is a skeptical possibility, such as the brain in a vat hypothesis, and q is a knowledge claim about the world:

  • If S doesn't know that not-sp, then S doesn't know that q
  • S doesn't know that not-sp
  • Therefore, S doesn't know that q
Moore's response
  • If S doesn't know that not-sp, then S doesn't know that q
  • S knows that q
  • Therefore, S knows that not-sp

Moore does not attack the skeptical premise; instead, he reverses the argument from being in the form of modus ponens to modus tollens. This logical maneuver is often called a G. E. Moore shift or a Moorean shift.

Read more about this topic:  Here Is A Hand

Famous quotes containing the word introduction:

    “Such is oftenest the young man’s introduction to the forest, and the most original part of himself. He goes thither at first as a hunter and fisher, until at last, if he has the seeds of a better life in him, he distinguishes his proper objects, as a poet or naturalist it may be, and leaves the gun and fish-pole behind. The mass of men are still and always young in this respect.”
    —Henry David Thoreau (1817–1862)

    “My objection to Liberalism is this—that it is the introduction into the practical business of life of the highest kind—namely, politics—of philosophical ideas instead of political principles.”
    —Benjamin Disraeli (1804–1881)

    “For better or worse, stepparenting is self-conscious parenting. You’re damned if you do, and damned if you don’t.”
    —Anonymous Parent. Making It as a Stepparent, by Claire Berman, introduction (1980, repr. 1986)