 It is worth noting that Leibniz believed the PSR before he developed his conceptual containment Theory of Truth. In fact, the PSR is one of Leibniz’s earliest and most stable philosophical commitments (see, for example, Leibniz’s 1671 letter to Wedderkopf A II.ii.117f/L146). This observation has led some scholars to conclude that rather than deriving the PSR from the conceptual containment theory of truth, Leibniz was in fact led to the conceptual containment theory from his antecedent commitment to the PSR. The conceptual containment theory explains how there could be a sufficient reason for every truth by guaranteeing that there will be an explanation in terms of conceptual relations (see Adams 1994: 69).