"I mean the word proof not in the sense of the lawyers, who set two half proofs equal to a whole one, but in the sense of a mathematician, where half proof = 0, and it is demanded for proof that every doubt becomes impossible"
About this Quote
The mathematician’s equation, “half proof = 0,” reads like a provocation, but it’s also a statement about what mathematics is for: not to convince, but to compel. The subtext is that proof isn’t a social contract. It’s a machine that, when properly built, leaves no daylight for interpretation. “Every doubt becomes impossible” is deliberately absolutist, a rhetorical flourish that sells the aspiration of rigor even if working mathematicians live amid conjecture, heuristics, and informal argument most of the time.
Context matters: Gauss is writing from an era when mathematics is professionalizing and tightening its standards, when “proof” is becoming the badge of the discipline’s authority. His definition is also a power move: it polices boundaries, declaring which kinds of reasoning count as knowledge and which are merely plausible stories. The line still stings because modern life runs on “half proofs” everywhere - statistics, policy, punditry - and Gauss reminds you that certainty is not a volume knob you turn up; it’s a different device entirely.
Quote Details
| Topic | Reason & Logic |
|---|---|
| Source | Later attribution: Fundamental Mathematical Analysis (Robert Magnus, 2020) modern compilationISBN: 9783030463212 · ID: 5hvxDwAAQBAJ
Evidence:
... I mean the word proof not in the sense of the lawyers , who set two half proofs equal to a whole one , but in the sense of a mathematician , where half proof = 0 , and it is demanded for proof that every doubt becomes impossible . C. F. ... |
| Cite |
Citation Formats
APA Style (7th ed.)
Gauss, Carl Friedrich. (2026, February 10). I mean the word proof not in the sense of the lawyers, who set two half proofs equal to a whole one, but in the sense of a mathematician, where half proof = 0, and it is demanded for proof that every doubt becomes impossible. FixQuotes. https://fixquotes.com/quotes/i-mean-the-word-proof-not-in-the-sense-of-the-46568/
Chicago Style
Gauss, Carl Friedrich. "I mean the word proof not in the sense of the lawyers, who set two half proofs equal to a whole one, but in the sense of a mathematician, where half proof = 0, and it is demanded for proof that every doubt becomes impossible." FixQuotes. February 10, 2026. https://fixquotes.com/quotes/i-mean-the-word-proof-not-in-the-sense-of-the-46568/.
MLA Style (9th ed.)
"I mean the word proof not in the sense of the lawyers, who set two half proofs equal to a whole one, but in the sense of a mathematician, where half proof = 0, and it is demanded for proof that every doubt becomes impossible." FixQuotes, 10 Feb. 2026, https://fixquotes.com/quotes/i-mean-the-word-proof-not-in-the-sense-of-the-46568/. Accessed 12 Feb. 2026.
