Q0327
“Prudence is right reason applied to action.” — Thomas Aquinas (Summa Theologiae II-II, q.47, a.2)
Verified English quotation. Primary source: Summa Theologiae II-II, q.47, a.2. Theme: wisdom.
English
Prudence is right reason applied to action.
Source and attribution
The archive attributes this English wording to Summa Theologiae II-II, q.47, a.2 and files it under Scholasticism. That locator distinguishes the passage from loose internet attributions: readers can return to the named work or section to check translation, surrounding argument, and edition-specific wording.
About Thomas Aquinas
Thomas Aquinas (1225–1274) was the Dominican scholastic who synthesized Aristotelian philosophy with Christian theology in the Summa Theologiae and Summa contra Gentiles. Educated at Naples, Paris, and Cologne under Albert the Great, he taught in Paris and Italian studia.
Interpretation
Aquinas's definition places prudence among the intellectual virtues while making it about action. Prudence is not caution; it is right reasoning about what to do here, which requires both a correct end and correct perception of circumstances. This is why he calls it right reason applied to action rather than knowledge of general rules — no general rule settles a particular case. It is, on his account, the virtue the others depend on.
Why it matters
It explains why good intentions and sound principles are not sufficient: something has to bridge from the general to this situation, and that bridge is the skill in question.
Concepts in this quote
- Wisdom
- Wisdom is practical insight under uncertainty: knowing what matters, what one does not know, and how to act without false certainty.
- Reason
- Reason is the capacity to give and assess reasons—central to logic, science, ethics, and public argument.
- Action
- Action concerns agency: what it is to do something intentionally, and how thought becomes practice.
How to cite this quotation
APA: Thomas Aquinas. (n.d.). Prudence is right reason applied to action. In Philosophy Blind Box. https://www.philosophydef.com/quotes/q0327
MLA: Thomas Aquinas. “Prudence is right reason applied to action..” Philosophy Blind Box, https://www.philosophydef.com/quotes/q0327.
Chicago: Thomas Aquinas. “Prudence is right reason applied to action..” Philosophy Blind Box. Accessed 2026. https://www.philosophydef.com/quotes/q0327.
Frequently asked questions
What is the source of the quotation “Prudence is right reason applied to action.”?
The passage is attributed to Thomas Aquinas, Summa Theologiae II-II, q.47, a.2. The archive attributes this English wording to Summa Theologiae II-II, q.47, a.2 and files it under Scholasticism. That locator distinguishes the passage from loose internet attributions: readers can return to the named work or section to check translation, surrounding argument, and edition-specific wording.
What does Thomas Aquinas mean by wisdom?
Unlike mere information, wisdom concerns judgment. Ancient schools linked it to virtue, moderation, and the right relation to desire. This passage enters that discussion through wisdom, reason, action.