Louis Doulas
University of California, Irvine
Since its publication in 1939, many philosophers have felt that there is something wrong with G.E. Moore’s infamous two-handed proof of an external world. What’s wrong is that it’s circular. Failing to be epistemically cogent in this way, Moore’s proof is therefore generally thought to be a bad one:
– Moore’s proof is epistemically circular, making it a bad proof.
Part of what’s puzzling is that nowhere in “Proof of an External World” (PEW) does Moore seem to address or anticipate such a worry. As Moore makes clear, he takes his proof to be a “perfectly good,” “perfectly conclusive” one (168). That is:
– Moore’s proof is epistemically cogent, making it a good proof.
So, we have a tension. Moore’s proof seems circular, yet Moore doesn’t seem to think so.
In this paper, I want to complicate this tension even further, by adding the following (undefended) claim to the mix:
– Moore knows that his proof is epistemically circular.
My aim in this paper is to develop a new reading of PEW that relaxes the apparent tension created by the three claims above. To do this, I draw on a overlooked and heretofore unexamined discussion of circularity in Moore’s Lectures on Philosophy (LP 1966) and show that Moore developed an account of epistemic circularity that predicts the circularity of his proof in PEW. I then suggest how a careful reading of PEW’s concluding passages show that Moore acknowledges this circularity. The key to dislodging the tensions above, however, is to understand these concessions in the following way: that Moore’s proof is circular when conceived as an anti-skeptical proof. Moore, that is, takes his proof to be circular against the skeptic (making it a bad anti-skeptical proof) but not the idealist (making it a good anti-idealist proof). Since it isn’t obvious that Moore’s proof is a good anti-idealist proof, however, I go on to show how the oft-neglected first half of PEW provides Moore with anti-circular justification for the key anti-idealist premise of his proof.
Chair: Sonja Riegler
Time: September 7th, 10:00-10:30
Location: SR 1.004
SOPhiA 2026 