If truth is unattainable, the censor cannot appeal to a higher truth as the ground for foreclosing further inquiry on a subject; but the libertarian, in resisting censorship, can appeal to the demonstrated efficacy of free inquiry in enlarging knowledge. One can doubt that we shall ever attain "truth," but not that our knowledge is growing steadily.

XREF: Connects to Popperian fallibilism and pragmatic defenses of free speech; echoes Mill's argument for open inquiry in On Liberty.

Richard A. Posner, Richard A. Posner - What Ha…, loc. 76