ABSTRACT
The reformulation of the Agrippan material into the Two Modes highlighted the problem of the criterion: if propositions are to be accepted on their own recognizance without the support of other propositions, then we need to find some marker of their acceptability, some means of discerning true from false coin. Moreover, this marker should be acceptable to everybody (or at the very least everybody who thinks clearly and rationally about it): for if it is not, the criterion itself will be a matter of doubt, and we shall be attempting to support the doubtful by way of something at least equally doubtful (this latter manoeuvre-which may be considered an extra Formal Mode-is pressed into service at PH 2 33, 120; 3 23; M 8 66, 180, 285-6).
