Abstract

This study has two goals: first, to show that Avicenna’s account of being and thing significantly influenced Aquinas’s doctrine of the primary notions; second, to establish the value of adopting a mereological construal of these primary notions in the metaphysics of Avicenna and Aquinas. I begin with an explication of the mereological construal of the primary notions that casts these notions in terms of wholes and parts. Being and thing refer to the same entitative whole and have the same extension, but they are distinct in intension according to the different entitative parts they signify. Existence and essence constitute the two most fundamental entitative parts of every entitative whole. Being is taken to mean that which has existence, and thing signifies that which has essence. I then show how this mereological construal of the primary notions clarifies a number of texts in Avicenna and Aquinas. Finally, I address a few arguments against employing this mereological interpretation of the primary notions