Sapiens nihil affirmat quod non probat
“A wise person states nothing they cannot prove.”
Latin maxim
What does “Sapiens nihil affirmat quod non probat” mean?
Sapiens nihil affirmat quod non probat translates as “A wise person states nothing they cannot prove.”
Speak only about what you can back up. A motto of science and critical thinking.
“Sapiens nihil affirmat quod non probat” word by word
| Latin | English | Grammar |
|---|---|---|
| Sapiens | a wise person | nominative singular of the adjective sapiens, “wise”, used as a noun; masculine in form, so “a wise man”, though it covers any wise person |
| nihil | nothing | indeclinable noun, here the direct object (accusative) of affirmat |
| affirmat | states, affirms | third person singular present indicative active of affirmo, “to assert” |
| quod | that which | relative pronoun, neuter accusative singular, object of probat; refers back to nihil |
| non | not | adverb of negation, placed before probat |
| probat | proves, can prove | third person singular present indicative active of probo, “to test, to prove” |
How to pronounce “Sapiens nihil affirmat quod non probat”
The main difference is nihil: classical NIH-hil, church NEE-keel (the h is often sounded like a k in Church Latin). Stress falls on pi in sapiens, on the first syllable of nihil, on fir in affirmat and on the first syllable of probat.
The story behind it
Word for word the line says “a wise person affirms nothing which he does not prove”. The Latin is compact: nihil quod non probat means “nothing that he does not prove”.
It is a traditional maxim of scholarly caution, usually dated to the Middle Ages, and we do not have a named author for it. It belongs to the habit of testing claims by argument and evidence before accepting them.
Today it is quoted as a motto for science, journalism and critical thinking, a short way of saying that confidence should match the proof you can offer.
How to use “Sapiens nihil affirmat quod non probat”
It suits a science or philosophy classroom, a research group or lab motto, a signature line for a writer or fact-checker, or a tattoo for someone who values evidence over opinion.
- Latin
- Sapiens nihil affirmat quod non probat
- English
- A wise person states nothing they cannot prove.
- Source
- Latin maxim
- Era
- Middle Ages (maxim)
- Theme
- Wisdom
Common mistakes
- It does not say a wise person never speaks. It says they claim nothing they cannot back up.
- Sapiens is masculine in form but works for any wise person. Changing it to a feminine form (sapiens stays the same in the nominative) is unnecessary.
- Do not turn it into “nothing is true unless proven”. The maxim is about what the speaker asserts, not about what is true.
- It is a maxim, not a quote from a famous author, so do not credit it to Cicero or another classical writer.
Questions about “Sapiens nihil affirmat quod non probat”
What does “Sapiens nihil affirmat quod non probat” mean literally?
“A wise person affirms nothing that he does not prove.” In plain English: a wise person claims only what they can prove.
Who said “Sapiens nihil affirmat quod non probat”?
No author is known. It is a traditional Latin maxim of scholarly caution, usually placed in the Middle Ages.
How do you pronounce “Sapiens nihil affirmat quod non probat”?
Classical: sah-PEE-ens NIH-hil af-FIR-maht kwod nohn PROH-baht. In Church Latin nihil becomes NEE-keel; the rest sounds much the same.
Is “Sapiens nihil affirmat quod non probat” correct Latin for a tattoo?
Yes, the grammar is sound. The word sapiens is masculine in form but is used for any wise person, so it works for anyone.
More to explore
Translation and grammar checked by Latin Quoter · last reviewed November 2026
One Latin line. Every Monday.
A quote, its translation and the story behind it, free in your inbox.