Well-known for his Ciceronianism as well as for his crass nominalism and virulent attack on universals, the humanist Mario Nizolio (1488-1567) is often considered to be a forerunner of early modern philosophy. But although his name duly features in general accounts of Renaissance humanism and philosophy, his work, edited by Leibniz in 1670, has hardly been the subject of a philosophically sensitive analysis. This article examines Nizolio's attempt to reform scholastic philosophy, paying particular attention to the way in which he de-ontologized the scholastic categories and predicables (genus, species, etc.) and replaced philosophical abstraction with the rhetorical concept of synecdoche. His views on science, proof argumentation, and rhetoric are discussed, as well as the humanist inspiration from which they issue. We will then be able to evaluate the strength and limitations of Nizolio's program in the wider tradition of early modern philosophy.