ABSTRACT: In this paper, I attempt to show how Davidson’s anti-sceptical argument can respond to the closureRK-based radical scepticism. My approach will focus on the closureRK principle rather than the possibility that our beliefs could be massively wrong. I first review Davidson’s principle of charity and the triangulation argument, and then I extract his theory on content of a belief. According to this theory, content of a belief is determined by its typical cause and other relevant beliefs. With this constraint on content, I argue that doubt must be local. Furthermore, since one cannot rationally believe that one’s commitment to the cause of beliefs could be false, our commitment to the denial of a sceptical hypothesis is not a knowledge-apt belief. Therefore, the closureRK principle is not applicable to rational evaluations of this commitment. As a result, the closureRK-based sceptical argument fails while the closureRK principle remains.