  But does Leibniz's account of necessity and contingency really amount to possible-worlds semantics for modality avant la lettre? While Leibniz had all the tools at his disposal to develop such an account of modality, he did not, or, at least, he did not do so explicitly in any texts. Rather, his account of the nature of necessity and contingency has more to do with his account of the nature of truth and the analysis of propositions. More specifically, it has to do with his doctrine of infinite analysis. In his piece On Contingency, Leibniz writes,