 McDowell is not content to concede any ground to the sceptic, and believes that appeal to criteria can confer (sceptic-proof) knowledge. But for this to be the case, criteria must be understood to be indefeasible (McDowell 1982). McDowell finds an incompatibility between, on the one hand, the legitimacy of a knowledge ascription and, on the other, the possible of its falsity (its defeasibility). McDowell is not persuaded by Wright’s understanding of criteria, and proposes an alternative to it. McDowell’s understanding of criteria is thought to form a part of his defense of a direct, perceptual, account of our knowledge of other minds (see  §1.4.1).  