Another metaphysical characterization of a sufficient reason connects with the Principle of the Best, which says that for any proposition p, p is true just in case p holds in the best possible world (G VI.448/DM 22; Mon. 46, 53, 54/G VI, 614–616). Is the Principle of the Best a supplement to the PSR or a rival to the PSR? It is, in fact, a consequence of the PSR in conjunction with three additional assumptions: (1) the sufficient reason for every choice is that the chooser perceives it to the be