Introduction

The purpose of these lectures is to introduce basic principles of Aquinas' metaphysics or ontology. I will examine the notions of form and matter as well as those of substance and accidents inherent properties of the substance. In the second lecture, I will consider analogical conceptions of being, in particular the concepts of being in actuality and being in potentiality. This division of being allows one to think about Aquinas' famous distinction between essay in Latin existence and sincere essence. We can also consider briefly why it is that Aquinas thinks that the world of ordinary, natural realities points us towards the existence of God as the transcendent origin of being.