This paper aims to analyze Nicholas of Cusa's treatise De Aequalitate (1459), focusing on the peculiar articulation of the concepts of ratio and causa present in it. Through an examination of the text, we intend to show how the Cardinal operates a semantic reconfiguration of these categories, removing them from a rigid scholastic approach and orienting them towards a new perspective, the metaphysical orientation of which, if there is one, will then be discussed. This theoretical operation allows us to place Nicholas of Cusa in a crucial position within the debate on the genesis of modernity, highlighting how his thought acts as a hinge between classical metaphysics and modern epistemological tensions. The analysis will aim to demonstrate that, in Cusa's thought, a redefinition of cause paves the way for an interpretation of the cardinal that places him as the original voice of a possible modernity that subsequent philosophy has not pursued, and which therefore provides us with a way of thinking for the contemporary world.