This colloquium talk is planned as an online event.
Leibniz holds that every truth is analytic. In every truth, he claims, the concept of the predicate is contained in the concept of the subject. For example, if it is true that Mary is tall, the concept of being tall is contained in Mary's individual concept. In this talk, I will examine the logical foundations of this account of truth. I discuss how the logical work done by Leibniz in the 1680s allows him to render every categorical and hypothetical truth as a case of conceptual containment. Moreover, we will see how his logical work leads him to maintain that every substance mirrors the whole universe, and hence that "when I perceive one thing or one mode of a thing, I always perceive the whole universe".