Best of Rationality Quotes
"Science is what we understand well enough to explain to a computer. Art is everything else we do. ... Science advances whenever an Art becomes a Science. And the state of the Art advances too because people always leap into new territory once they have understood more about the old."
-- Donald Knuth
"One can measure the importance of a scientific work by the number of earlier publications rendered superfluous by it."
-- David Hilbert
There is a mathematical style in which proofs are presented as strings of unmotivated tricks that miraculously do the job, but we found greater intellectual satisfaction in showing how each next step in the argument, if not actually forced, is at least something sweetly reasonable to try. Another reason for avoiding [pulling] rabbits [out of the magicians's hat] as much as possible was that we did not want to teach proofs, we wanted to teach proof design. Eventually, expelling rabbits became another joy of my professional life.
-- Edsger Dijkstra
Edit: Added context to "rabbits" in brackets.
According to an old story, a lord of ancient China once asked his physician, a member of a family of healers, which of them was the most skilled in the art.
The physician, whose reputation was such that his name became synonymous with medical science in China, replied, "My eldest brother sees the spirit of sickness and removes it before it takes shape and so his name does not get out of the house."
"My elder brother cures sickness when it is still extremely minute, so his name does not get out of the neighborhood."
"As for me, I puncture veins, prescribe potions, and massage skin, so from time to time my name gets out and is heard among the lords."
-- Thomas Cleary, Introduction to The Art of War
Testing shows the presence, not the absence of bugs.
-- Edsger Dijkstra
Take the thoughts of such an one, used for many years to one tract, out of that narrow compass he has been all his life confined to, you will find him no more capable of reasoning than almost a perfect natural. Some one or two rules on which their conclusions immediately depend you will find in most men have governed all their thoughts; these, true or false, have been the maxims they have been guided by. Take these from them, and they are perfectly at a loss, their compass and polestar then are gone and their understanding is perfectly at a nonplus; and therefore they either immediately return to their old maxims again as the foundations of all truth to them, notwithstanding all that can be said to show their weakness, or, if they give them up to their reasons, they with them give up all truth and further enquiry and think there is no such thing as certainty.
-- John Locke, Of the Conduct of Understanding
"Muad'Dib learned rapidly because his first training was in how to learn. And the first lesson of all was the basic trust that he could learn. It's shocking to find how many people do not believe they can learn, and how many more believe learning to be difficult. Muad'Dib knew that every experience carries its lesson."
-- Frank Herbert, Dune