Abstract
According to Thomas Aquinas, the ideas in the mind of God serve two distinct although interrelated roles: (1) as epistemological principles accounting for God’s knowledge of things other than himself, and (2) as ontological or causal principles involved in God’s creative activity. This article examines the causal role of the divine ideas by focusing on their relation to natural agents. Given Thomas’s observation that from God’s intellect “forms flow forth (effluunt) into all creatures,” the article considers whether the causality of the divine ideas excludes that of natural agents, or whether both modes of causality can somehow produce one and the same effect.