"It is necessary to posit something which is necessary of itself, and has no cause of its necessity outside of itself but is the cause of necessity in other things. And all people call this thing God"
About this Quote
The subtext is a quiet rebuke to two audiences at once. To skeptics, Aquinas suggests that refusing a self-necessary ground doesn’t make you rigorously rational; it makes you endlessly defer the bill. To believers, he insists that “God” isn’t primarily a character in a story but the metaphysical condition that keeps causes and explanations from collapsing into “and then…and then…and then.”
Context matters: 13th-century scholasticism is where Aristotle meets Christian doctrine under the university system’s newly sharpened tools of logic. Aquinas is building a bridge between faith and reason that can withstand professional interrogation. His language (“necessary of itself,” “cause of necessity”) is deliberately technical, not devotional. Then comes the sly pivot: “And all people call this thing God.” He smuggles the conclusion into common speech, implying the argument isn’t inventing a new entity so much as clarifying what we’re already naming when we say “God” with intellectual seriousness.
Quote Details
| Topic | God |
|---|---|
| Source | Thomas Aquinas, Summa Theologiae (Summa Theologica), Part I (Prima Pars), Question 2, Article 3 — the 'Third Way' (argument from possibility and necessity) in many English translations contains this passage. |
| Cite |
Citation Formats
APA Style (7th ed.)
Aquinas, Thomas. (2026, January 18). It is necessary to posit something which is necessary of itself, and has no cause of its necessity outside of itself but is the cause of necessity in other things. And all people call this thing God. FixQuotes. https://fixquotes.com/quotes/it-is-necessary-to-posit-something-which-is-10282/
Chicago Style
Aquinas, Thomas. "It is necessary to posit something which is necessary of itself, and has no cause of its necessity outside of itself but is the cause of necessity in other things. And all people call this thing God." FixQuotes. January 18, 2026. https://fixquotes.com/quotes/it-is-necessary-to-posit-something-which-is-10282/.
MLA Style (9th ed.)
"It is necessary to posit something which is necessary of itself, and has no cause of its necessity outside of itself but is the cause of necessity in other things. And all people call this thing God." FixQuotes, 18 Jan. 2026, https://fixquotes.com/quotes/it-is-necessary-to-posit-something-which-is-10282/. Accessed 12 Feb. 2026.











