Leibniz’s treatement of contingency proceeds by degrees and develops in parallel to the systematizations of his thought. In the time about the Confessio Philosophi, he sustains the idea of contingency on the possible as such, in the hypothetical necessity and in the divine creation. In the years previous to the systematization of the Discours de Métaphysique (1680-1686), Leibniz defends the idea of contingency through the following factors: the complete notion of substance, the infinite analysis of the truths and the first decree of the divine will.