Abstract

Passages in Leibniz which have been understood to contain his statement of Leibniz law do not in fact contain any statement of that principle. Some of these passages contain a statement of the principle of the identity of indiscernibles, While others contain a statement of a principle about concept identity. The latter principle states that a concept, A, Is identical with a concept, B, If and only if a can be substituted for b in any proposition without change of truth value