Here is one hand is an epistemological argument created by G. E. Moore in reaction against philosophical skepticism about the external world and in support of common sense.
The argument takes the following form: G. E. Moore wrote "A Defence of Common Sense" and Proof of an External World.
For the purposes of these essays, he posed skeptical hypotheses, such as that according to which we are disembodied souls living in an immaterial world with the mere hallucination of ordinary things induced by a Cartesian evil demon, and then provided his own response to them.
Where S is a subject, sk is a skeptical possibility, such as the evil demon hypothesis or the more recent brain in a vat hypothesis, and q is any fact that supposedly exists in the world (e.g. the fact that there are trees and mountains): Moore does not attack the first premise of the skeptic's argument, but denies its conclusion and uses this negation as the second premises of his own argument.
"[3] Some subsequent philosophers (especially those inclined to skeptical doubts) have found Moore's method of argument unconvincing.
His last writings in the six weeks before his death in 1951 were an attempt to respond comprehensively to Moore's argument, the fourth time in two years he had tried to do so.
[6] Wright has famously argued that Moore's proof is subtly circular so that it cannot provide justification for believing its conclusion.
Clearly, this evidence can justify J for John only if he already has justification for believing that the girl is not Jocelyn (i.e. Jessica's indistinguishable twin).
In other words, conservatives must explain where our independent justification for ruling out error hypotheses comes from in general, which appears to be very hard.
)[9] Pryor rejects conservatism and embraces a form of liberalism about perception that he calls "perceptual dogmatism."
Luca Moretti has recently proposed an alternative interpretation of the apparent "oddness" of Moore's proof.