  Arguably, the first employment in the western philosophical tradition of the notion of proposition, in roughly our sense, is found in the writings of the Stoics. In the third century B.C., Zeno and his followers, including Chrysippus especially, distinguished the material aspects of words from that which is said, or lekta. Among lekta, they distinguished the complete from incomplete (or deficient), the latter corresponding roughly to the meanings of predicates, the former to the meanings of sentences. Among complete lekta they included axiomata, or the meanings of declarative sentences. For the Stoics, only axiomata, and not the words used to articulate them, were properly said to be true or false. Axiomata were therefore the proper subject matter of Stoic logic.