“All intelligent thoughts have already been thought;
what is necessary is only to try to think them again.”

Source: Tractatus Logico-Philosophicus

Spark (2014)

Scènes de la vie future (1930), p. 52

Torvalds to his mother, about his sister
2000s, (2001)

Quote in Jorn's letter to anthropologist Francis Huxley (1970) - on the magical character of thinking and images
1959 - 1973, Various sources

Global Ideas from Pluto's Challenger (May 21, 2009)
Context: Creativity is seeing what everyone else sees, but then thinking a new thought that has never been thought before and expressing it somehow. It could be with art, a sculpture, music or even in science. The difference, however, between scientific creativity and any other kind of creativity, is that no matter how long you wait, no one else will ever compose "Beethoven's Ninth Symphony" except for Beethoven. No matter what you do, no one else will paint Van Gogh's "Starry Night." Only Van Gogh could do that because it came from his creativity.Whereas in science, you can't just make stuff up and presume that it is a proper account of nature. At the end of the day, you have to answer to nature. Since everyone has nature to answer to, your creativity is simply discovering something about the natural world that somebody else would have eventually discovered exactly the same way. They might have come through a different path, but they would have landed in the same place.Even though we name theorems and equations after the people who discover them — Newton's laws of gravity, Kepler's laws of planetary motion — somebody else would have discovered them afterward. It's that simple. Your creativity is not a boundless creativity.

Man's Unconquerable Mind (1954)

Source: Anna Karenina