Complexio, enunciatio, assensus: The role of propositions in knowledge according to John Buridan

Abstract

This paper examines Buridan's conception of scientia as opposed to error, opinio and fides. Since scientia (as well as error, opinio and fides) is the intellectual assent to some proposition, I will try to support the hypothesis that the specific nature and structure of propositions plays an essential role in Buridan's theory of human knowledge. On the one hand, the fact that a proposition is not a mere complexio but an enunciatio, capable of being true or false, determines that human knowledge is open to error. On the other hand, since a proposition may be not only apprehended but also judged to be true, there must be some causes that move the intellect from apprehensio to assensus. Given the natural inclination of the intellect to truth, the fact that some propositions are such that they can manifest their own truth and some others are not, seems to be the explanation of why the human mind wavers between scientific knowledge and opinion, and also of the difference between science and faith. As Buridan explains the truth conditions of propositions in terms of the semantic property of suppositio, the hypothesis that propositions play a role in knowledge can be tested by examining the contribution of suppositio to the grasping of truth.