"To know that we know what we know, and to know that we do not know what we do not know, that is true knowledge"
About this Quote
The historical context sharpens the edge. Copernicus didn’t just propose that the Earth moves; he proposed that inherited “common sense” and centuries of sanctioned astronomy could be wrong. In that world, confidence wasn’t just a personality trait, it was institutional glue. So the quote functions as preemptive defense: if you can name your unknowns, you’re not reckless or heretical, you’re rigorous. He’s quietly repositioning skepticism as a virtue rather than a threat.
The subtext is aimed at two targets. One is the pompous expert who mistakes tradition for proof: you may know many things, but you don’t know what you don’t know, and that blind spot is where error breeds. The other is the anxious novice: admitting ignorance isn’t failure; it’s the start of real inquiry. “True knowledge” here isn’t a hoard of facts, it’s epistemic self-control - the posture that made a heliocentric universe imaginable, and survivable, in a culture invested in the opposite.
Quote Details
| Topic | Knowledge |
|---|---|
| Source | Help us find the source |
| Cite |
Citation Formats
APA Style (7th ed.)
Copernicus, Nicolaus. (2026, January 15). To know that we know what we know, and to know that we do not know what we do not know, that is true knowledge. FixQuotes. https://fixquotes.com/quotes/to-know-that-we-know-what-we-know-and-to-know-33378/
Chicago Style
Copernicus, Nicolaus. "To know that we know what we know, and to know that we do not know what we do not know, that is true knowledge." FixQuotes. January 15, 2026. https://fixquotes.com/quotes/to-know-that-we-know-what-we-know-and-to-know-33378/.
MLA Style (9th ed.)
"To know that we know what we know, and to know that we do not know what we do not know, that is true knowledge." FixQuotes, 15 Jan. 2026, https://fixquotes.com/quotes/to-know-that-we-know-what-we-know-and-to-know-33378/. Accessed 12 Feb. 2026.










