Question 3: On the Simplicity of God
We continue our exploration of Thomas Aquinas’s monumental work, the “Summa Theologica”. In this episode, we dive into the third question: On the Simplicity of God.
Aquinas argues that God cannot be a body because He is the First Mover, devoid of potentiality, and must be of the highest nobility, transcending corporeal form. He cites John 4:24, “God is Spirit,” to support this, emphasizing God’s spiritual nature.
Regarding whether God is composed of matter and form, Aquinas dismisses this notion. He explains that attributions like soul or anger to God in Scripture are metaphorical, not literal. God, being pure act without potentiality, cannot be composed of matter and form, which would imply participated rather than essential goodness.
On the identity of God’s essence with His nature, Aquinas notes that in composite beings, essence and individual existence differ due to matter, but in God, who is pure form, there’s no such distinction; He is His essence.
Aquinas further argues that God’s essence and existence are identical. If they were separate, God would need an external cause, contradicting His role as the First Cause. Also, since God is pure actuality, His existence and essence must be one to maintain His status as the uncaused, first being.
He also asserts that God cannot be classified within any genus because He is pure actuality, His existence is His essence, and He transcends all categories, including “being” itself, which cannot be a genus.
Aquinas concludes that God has no accidents, for accidents imply potentiality, and God is pure act. Since God is the primal being, nothing can be added to or subtracted from His essence.
Lastly, he discusses the simplicity of God, arguing that God lacks composition in any form—quantitative, material, or otherwise—since He is the first cause and pure actuality.
Aquinas also refutes historical errors suggesting God is part of creation, whether as the world-soul, formal principle, or primary matter, emphasizing that God, as the first efficient cause, cannot be part of any composition or be derivative in nature.
