Abstract

The thesis of this paper is that philosophers are often too hasty in rejecting justifications because the argument that yields the justification is circular. Circularity is distinguished from vicious circularity and several examples are examined in which a proposed justification is circular in a precise sense, but not viciously circular. These include an observational procedure which could yield a velocity in excess of the velocity of light even though the impossibility of such velocities is assumed at a key step in analyzing the data, and an argument that uses a specific argument form to show that that form is invalid.