Simplicity and Perfection

Abstract

Aquinas’ understanding of God is informed throughout by the primacy that he gives to the concept of divine simplicity. The structure of the Summa itself reflects this ontological primacy; for example, the “proof” of God’s simplicity (in Q3) follows immediately upon the arguments for God. This means that every statement about the quality of divine being (including the Trinitarian statements which begin with Q27) must be brought into line with the notion of simplicity. There is, of course, some Biblical and philosophical justification for this ontological and structural primacy. In the “sh’mai” of the Old Testament, the first affirmation about God is that He “is one God”, and in Plotinus’ thought the simplicity of divine being is fundamental. Nevertheless the questions I wish to draw attention to concern not the historical roots of the doctrine, but its cogency, not its hoary authority but its uneasy relationship to Trinitarian thought.