Differential logic is the logic of variation — the logic of change and difference.
Differential logic is the component of logic whose object is the successful description of variation — for example, the aspects of change, difference, distribution, and diversity — in universes of discourse that are subject to logical description. Viewed from the perspective of formal or symbolic logic, differential logic treats the principles that govern the use of a differential logical calculus, that is, a formal system — a formal language plus explicit principles of transformation — that has the expressive capacity to describe change and diversity in logical universes of discourse.
A simple example of a differential logical calculus is furnished by differential propositional calculus. This augments ordinary propositional calculus in the same way that the differential calculus of Leibniz and Newton augments the analytic geometry of Descartes.