The ultimate measure of a man is not where he stands in moments of comfort and convenience, but where he stands at times of challenge and controversy.
— Martin Luther King, Jr.

When a thing ceases to be a subject of controversy, it ceases to be a subject of interest.
William Hazlitt controversy quote

The dust of controversy is merely the falsehood flying off.
— Thomas Carlyle

Change is one thing, progress is another. Change is scientific, progress is ethical; change is indubitable, whereas progress is a matter of controversy.
— Bertrand Russell

No sane person should believe that something is subjective merely because it cannot be settled beyond controversy.
— Hilary Putnam