Courage and overcoming setbacks
If a marker were to be erected today, it might read, in homage to his scientific courage: ‘He preferred the hard truth to his dearest illusions.’
— Carl Sagan (1934–1996), Cosmos (1980), On the character of Johannes Kepler, p. 67

Courage and overcoming setbacks

What it means

Sagan honours Kepler for accepting an uncomfortable truth over a beloved theory. Intellectual courage means following the evidence.

“His” is Johannes Kepler: the line closes Sagan’s account of how Kepler abandoned his own cherished model of the planets when it disagreed with the observations.

About the author

Carl Sagan — American scientist and science communicator (1934–1996).

Source and verification

Source
Cosmos (1980), On the character of Johannes Kepler, p. 67
Reference
Carl Sagan on Wikiquote
Checked
Wording and source taken from the sourced section of the author’s Wikiquote page, which cites the work given here (accessed 2026-10-11).
Copyright
Short quotation from a work that is still in copyright, reproduced briefly for commentary with full attribution. Rights remain with the author or their estate.

The explanation above is ToDoMatriX’s own reading of the quote, not the author’s words.

More on courage and overcoming setbacks

“Do not worry about your difficulties in Mathematics. I can assure you mine are still greater.”

Albert Einstein

“In short, in life, as in a football game, the principle to follow is: Hit the line hard; don't foul and don't shirk, but hit the line hard!”

Theodore Roosevelt

“I have never in my life envied a human being who led an easy life; I have envied a great many people who led difficult lives and led them well.”

Theodore Roosevelt