Cognitive propositions, truth functions and the Tractatus

Over a century ago Frege, Russell, and Wittgenstein put propositions at the center of philosophy of language, logic, mathematics and mind. By 1912 Russell had become dissatisfied with his earlier efforts, which were at best models of what we assert, believe, and know. He was then struck with the idea that what unites the elements of assertion and belief, and gives them representational content are the minds of agents. Although he failed to capitalize on this idea, Wittgenstein was more successful. The tractarian theory of propositions was grounded in our use of linguistic, and other, artifacts to represent things as being one way or another. Despite remaining long submerged, his idea has now been revived in cognitive form by several philosophers. The present article is part of that revival. Although we have made great progress in the philosophy of mind and language, we still don't know nearly enough about propositions. If that progress is to continue we must develop our conception of propositions as primary bearers of truth conditions, objects of attitudes, and contents of some mental states. It is striking that classic texts like the Tractatus continue to shed light on this task.