This paper is focused on one of the most important philosophers in Italy during the last decades of the fifteenth century – Nicoletto Vernia – and on his account of medicine and civil law. This is the first attempt at presenting Vernia’s achievements in the context of Renaissance scholasticism, a particular philosophical context which is still and by and large neglected by many scholars of Renaissance philosophy, of which Vernia was a genuine representative. Questions regarding, for instance, what science is or what a proper scientific procedure should be are discussed through this debate between disciplines, where Vernia shows just how much he is willing to go beyond the Aristotelian framework. It is here that we find one of the earliest formulations of the notion of a universal rationality, while reducing moral philosophy to natural philosophy, which turns out to be the necessary foundation for every other science.