Words ought to be a little wild for they are the assaults of thought on the unthinking.
John Maynard Keynes (1883 - 1946)
The significant problems we have cannot be solved at the same level of thinking with which we created them.
Albert Einstein (1879 - 1955)
Discovery consists of seeing what everybody has seen and thinking what nobody has thought.
Albert Szent-Gyorgyi (1893 - 1986), in Irving Good, The Scientist Speculates (1962)
Avoid the crowd. Do your own thinking independently. Be the chess player, not the chess piece.
The freethinking of one age is the common sense of the next.
Matthew Arnold (1822 - 1888), 'God and the Bible,' 1875
The spirit of the age is filled with the disdain for thinking.
Albert Schweitzer (1875 - 1965)
There is nothing either good or bad, but thinking makes it so.
William Shakespeare (1564 - 1616), "Hamlet", Act 2 scene 2