Leibniz was undoubtedly a many-sided man, and a polymathic mind, if ever there was one. The concept of analysis is notoriously, for its part, a polycephalous monster, and nearly all its meanings are spread through Leibniz’s works, in juridical, scientific, mathematical, or philosophical contexts, under different conditions and with different purposes. Yet even for such manifold uses should exist some common ground and univocal meaning. The analysis of thoughts and that of truths, the analysis of problems and that of things, all imply slightly or consistently different proceedings, and nevertheless they must perform somehow one and the same operation. This is the object of the present paper, supplied here in post-print version.