“It was thought in the Middle Ages that people simply make many observations, and the observations themselves suggest the laws. But it does not work that way. It takes much more imagination than that.So the next thing we have to talk about is where the new ideas come from. Actually, it does not make any difference, as long as they come.”

“In general, we look for a new law by the following process: First we guess it; then we compute the consequences of the guess to see what would be implied if this law that we guessed is right; then we compare the result of the computation to nature, with experiment or experience, compare it directly with observation, to see if it works. If it disagrees with experiment, it is wrong. In that simple statement is the key to science. It does not make any difference how beautiful your guess is, it does not make any difference how smart you are, who made the guess, or what his name is — if it disagrees with experiment, it is wrong.”

“How much does one imagine, how much observe? One can no more separate those functions than divide light from air, or wetness from water.”

“In the twentieth century, one encounters artworks that seek to cancel the difference between a real and an imagined reality by presenting themselves in ways that make them indistinguishable from real objects. Should we take this trend as an internal reaction of art against itself? … No ordinary object insists on being taken for an ordinary thing, but a work that does so betrays itself by this very effort. The function of art in such a case is to reproduce the difference of art. But the mere fact that art seeks to cancel this difference and fails in its effort to do so perhaps says more about art than could any excuse or critique.”

“First comes thought; then organization of that thought, into ideas and plans; then transformation of those plans into reality. The beginning, as you will observe, is in your imagination.”

“To produce a valuable observation, one has first to have an idea of what to observe, a preconception of what is possible. Scientific advances often come from uncovering a hitherto unseen aspect of things as a result, not so much of using new instruments, but rather of looking at objects from a different angle. This look is necessarily guided by a certain idea of what this so-called reality might be. It always involves a certain conception about the unknown, that is, about what lies beyond that which one has logical or experimental reasons to believe.”