A nation that silences or intimidates original minds is left only with unoriginal minds and cannot hope to hold its own in the competition of peace or of war.

Henry Steele Commager (1902-1998) American historian, writer, activist

Essay (1953-02-21), “Is Freedom Really Necessary?” Saturday Review
    (Source)

Based on a discussion by the American Round Table, New York City (1951). Collected as "Free Enterprise in Ideas," Freedom, Loyalty and Dissent (1954).