Convictions are more dangerous enemies of the truth than lies.
Friedrich Nietzche

The Great enemy of the truth is very often not the lie-deliberate, contrived, and dishonest-but the myth-persistent, persuasive and unrealistic. . . .
We subject all facts to a prefabricated set of interpolations. We enjoy the comfort of opinion without the discomfort of thought.
John F Kennedy, Commencement address Yale University, 1962