How to Justify Metaphysical Principles:

A Lesson from Arguments over Ramseyan Humility

Abstract

    David Lewis argues that the thesis of Humility follows from two metaphysical principles; combinatorial principle and quidditism. The thesis has received attention of philosophers because of its skeptical implication, but only by focusing on that point one may underestimate the significance of Humility. Another implication drawn from the thesis pertains to the methodological issue, that is, justification of metaphysical principles. A key for the justification of two metaphysical principles in question is correspondence between our thought and the world, and it is required to develop modal epistemology in the way to oppose to Saul Kripke's view.