What is a world? A piece of rock? A place to live? An entity? Who are we to know?
We are only seeking Man. We have no need of other worlds. We need mirrors. We don’t know what to do with other worlds. A single world, our own, suffices us; but we can’t accept it for what it is. We are seaching for an ideal image of our own world: we go in quest of a planet, of a civilisation superior to our own but developed on the basis of a prototype of our primeval past. (Stanislaw Lem 1961.)