Contingência e análise infinita em Leibniz

leibniz says in various occasions that infinite analysis is the key concept to explain the compatibillity of determinism and contingence. it is not evident, however, why the analogical use of a mathematical concept, such as infinitesimal calculus, could solve this ontological problem, nor in what sense one should understand such analogy. the aim of this paper is to elucidate these two points.