We know that the only way to avoid error is to detect it, that the only way to detect it is to be free to enquire.

From "Encouragement of Science" by Robert Oppenheimer, (Address at Science Talent Institute, 6 Mar 1950), Bulletin of the Atomic Scientists, v.7, #1 (Jan 1951) p. 6-8

We do not believe any group of men adequate enough or wise enough to operate without scrutiny or without criticism. We know that the only way to avoid error is to detect it, that the only way to detect it is to be free to enquire. We know that the wages of secrecy are corruption. We know that in secrecy error, undetected, will flourish and subvert.

Oppenheimer had expressed a similar sentiment a couple of years earlier, as quoted in "J. Robert Oppenheimer" by L. Barnett, in Life, Vol. 7, No. 9, International Edition (24 October 1949), p. 58.

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.

That is what makes the trends in universities and government agencies so alarming. The Department of Justice, the FBI and the IRS all appear to have been suborned into suppressing speech and opinions. Our universities seem to have devolved into playpens for cognitive dwarves where no thought is to be expressed if there is a risk that someone might take offense. These are alien behaviors and creeds. We need to reclaim, and with conviction, the principles of freedom, especially freedom of speech and belief.