Back to Aquinas Arguments

Metaphysics

Act and potency

Change is intelligible because a being can possess a real capacity that is brought into actuality.

Guiding question

How can change be real without making contradiction real?

Why it matters

This distinction supports Aquinas's account of motion, causality, finite perfection, and the difference between creatures and God.

The argumentative movement

  1. 1Identify what is already actual in a subject and what remains only possible.
  2. 2Explain change as the actualization of a real potency by something already actual.
  3. 3Use the distinction to show why finite beings are limited and why God is not changeable.