"I cannot give any scientist of any age better advice than this: The intensity of a conviction that a hypothesis is true has no bearing over whether it is true or not"
About this Quote
The intent is almost parental: a senior scientist talking to younger ones about how self-deception scales with ambition. “Intensity” is doing a lot of work here. It captures the lab’s quiet drama - late nights, reputations on the line, the intoxicating coherence of a theory that suddenly makes the world feel legible. Medawar’s subtext is that conviction is not merely irrelevant to truth; it can actively interfere with the machinery that gets you there. If you need your idea to be true, you will start negotiating with the data: overfitting, cherry-picking, inventing ad hoc fixes that preserve the story and postpone embarrassment.
Context matters: Medawar helped shape modern thinking about scientific method and its psychological pitfalls, pushing back on the romantic myth that science advances by pure, heroic induction. This sentence aligns with Popper-era humility but keeps its edge: nature doesn’t bargain. Reality is not impressed by sincerity, only by tests that can break your favorite thought.
Quote Details
| Topic | Reason & Logic |
|---|---|
| Source | Peter Medawar — attributed in his entry on Wikiquote; phrasing matches the line commonly cited from his essay collection 'Advice to a Young Scientist'. |
| Cite |
Citation Formats
APA Style (7th ed.)
Medawar, Peter. (2026, February 17). I cannot give any scientist of any age better advice than this: The intensity of a conviction that a hypothesis is true has no bearing over whether it is true or not. FixQuotes. https://fixquotes.com/quotes/i-cannot-give-any-scientist-of-any-age-better-161631/
Chicago Style
Medawar, Peter. "I cannot give any scientist of any age better advice than this: The intensity of a conviction that a hypothesis is true has no bearing over whether it is true or not." FixQuotes. February 17, 2026. https://fixquotes.com/quotes/i-cannot-give-any-scientist-of-any-age-better-161631/.
MLA Style (9th ed.)
"I cannot give any scientist of any age better advice than this: The intensity of a conviction that a hypothesis is true has no bearing over whether it is true or not." FixQuotes, 17 Feb. 2026, https://fixquotes.com/quotes/i-cannot-give-any-scientist-of-any-age-better-161631/. Accessed 21 Feb. 2026.






