Albert Guérard, The Testament of a Liberal (1956):
[R]oughness, for all its bluff vigor, can be the most insidious enemy of thought. Never speak roughly, and above all strive never to think roughly. There is more peril in a rough truth than in a refined delusion. For a refined delusion, carried to the extreme point of refinement, is self-refuting. A rough truth tends to get rougher, more hopelessly entangled with errors and lies; and its core of rightness breeds self-righteousness, which drugs the intellect and perverts the will. A rough truth is bound to seek the support of rough force: in the vernacular, to get tough and crack down on its opponents. A rough truth roughly enforced means fanaticism, the never-failing source of most human ills.