What would the Astronomer say to the doctrine that the planets moved (not) according to the law of gravitation, but from the Creator having willed each separate planet to move in its particular orbit?
— Charles Darwin, 1842
[People say] "But evolution is only a theory!", which is true, I mean it is a theory and it's good they say that, I think, because it gives you hope, doesn't it? That they feel the same way about the theory of gravity and they might just float the fuck away...
I don't know, lately I get the feeling that I'm not so much being pulled down as I am being pushed.
— Phoebe, Friends
All political philosophies have to decide when their arguments are turning into the questioning of gravity.
— The Blank Slate: The Modern Denial of Human Nature by Steven Pinker