J. Robert Oppenheimer Quote
There must be no barriers to freedom of inquiry … There is no place for dogma in science. The scientist is free, and must be free to ask any question, to doubt any assertion, to seek for any evidence, to correct any errors. Our political life is also predicated on openness. We know that the only way to avoid error is to detect it and that the only way to detect it is to be free to inquire. And we know that as long as men are free to ask what they must, free to say what they think, free to think what they will, freedom can never be lost, and science can never regress.
As quoted in "J. Robert Oppenheimer" by L. Barnett, in Life, Vol. 7, No. 9, International Edition (24 October 1949), p. 58; sometimes a partial version (the final sentence) is misattributed to Marcel Proust.