How does Aquinas’s Fourth Way use degrees of perfection in its argument for God?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

St. Thomas Aquinas Enthroned Between the Doctors of the Old and New Testaments, with Personifications of the Virtues, Sciences, and Liberal Arts, fresco by Andrea da Firenze, c. 1365; in the Spanish Chapel of the Church of Santa Maria Novella, Florence. — Thomism *St. Thomas Aquinas Enthroned Between the Doctors of the Old and New Testaments, with Personifications of the Virtues, Sciences, and Liberal Arts*, fresco by Andrea da Firenze, c. 1365; in the Spanish Chapel of the Church of Santa Maria Novella, Florence.

In his Summa Theologica, St. Thomas Aquinas presents the Fourth Way as an argument derived from the observation of varying degrees of perfection in the natural world.1

The argument functions through the following logic:

Observation of Gradation: Aquinas notes that all things in the universe exhibit greater or lesser degrees of qualities such as goodness, truth, and nobility.1
The Standard of Perfection: Because these qualities exist in varying degrees, there must logically exist a maximum or "supreme perfection" against which these lesser degrees are measured.1
Identification with God: Aquinas concludes that this supreme, paramount perfection—which all imperfect beings approach but never fully attain—is God.1

This argument is a key component of his natural theology, serving as one of the Five Ways intended to demonstrate the existence of God through the observable order of the natural world.1