False Ideas: Leibniz and Aquinas

Though accepting the traditional view that truth and falsity are properties of propositions and judgments, Leibniz does not refrain from predicating truth and falsity of pre-judgmental items such as ideas, which he considers to be true iff logically consistent, and false otherwise. Elsewhere, however, Leibniz claims that ideas are true or false only insofar as they include the (true or false) affirmation that their object is possible. This paper aims to cast light on Leibniz’s doctrine of ideas as truth-bearers by exploring its historical background. On the one hand, Leibniz’s pronouncements reflect his reaction to the post-Cartesian debates. On the other hand, they appear to be inspired from Aquinas’s doctrine of accidental falsity.