All new ideas begin in a non-conforming mind that questions some tenet of the conventional wisdom.
Hyman RickoverTo doubt one's own first principles is the mark of a civilized man. Don't defend past actions; what is right today may be wrong tomorrow. Don't be consistent; consistency is the refuge of fools.
Hyman RickoverGood ideas are not adopted automatically. They must be driven into practice with courageous impatience. Once implemented they can be easily overturned or subverted through apathy or lack of follow-up, so a continuous effort is required.
Hyman Rickover