Lessened by Addition: Procession by Diminution in Proclus and Aquinas

Aquinas's doctrine of creatures as participants of esse in relation to God as ipsum esse is structurally parallel to Proclus's triadic schema of participating, participated, and unparticipated terms. For Proclus, a multiplicity of participated terms are diminished relative to their unparticipated monad in that each is confined to its participant. Since all things exist by participating one, unparticipated one itself is the first principle of all things. For Aquinas, all things exist by participating esse, and the esse of each is contracted to its participant. Hence unparticipated esse itself is the first principle. In both Proclus and Aquinas, therefore, we must "take away" all things, as participants of one or esse, from the first principle, leaving no thought whatever that grasps the first itself. Aquinas's understanding of creation as the posteriority of all things as participants of esse to God as ipsum esse is thus altogether Platonic and Procline in character.