One can even conjecture that Lisp owes its survival specifically to the fact that its programs are lists, which everyone, including me, has regarded … - John McCarthy

Program designers have a tendency to think of the users as idiots who need to be controlled. They should rather think of their program as a servant, whose master, the user, should be able to control it. If designers and programmers think about the apparent mental qualities that their programs will have, they'll create programs that are easier and pleasanter — more humane — to deal with.

Whenever we write an axiom, a critic can say that the axiom is true only in a certain context. With a little ingenuity the critic can usually devise a more general context in which the precise form of the axiom doesn't hold. [...] There simply isn't a most general context.

He who refuses to do arithmetic is doomed to talk nonsense.