Leibniz’ principal doctrine of truth is an attempt to set out the truth-conditions for a certain syntactically-defined class of propositions. As such, it constitutes an attempt to provide at least one portion of a semantical theory. The doctrine itself is found for example in Elementa Calculi:Every true categorical proposition, affirmative and universal, signifies nothing but a certain connection between the predicate and the subject… This connection is such that the predicate is said to be in the subject, or to be (...) contained in it, and this either absolutely and viewed in itself, or in some particular case. Or in the same way, the subject is said to contain the predicate; that is, the notion of the subject, either in itself or with some addition, involves the notion of the predicate.It is clear, from this work as well as from “First Truths” and “On Freedom”, that the doctrine is not restricted to universal affirmatives, but applies as well to particular affirmatives. (shrink)