Some consider the puzzles that are created by their omissions as spicy challenges, without which their texts would be boring; others shun clarity lest their work is considered trivial.

The effective exploitation of his powers of abstraction must be regarded as one of the most vital activities of a competent programmer.

In their capacity as a tool, computers will be but a ripple on the surface of our culture. In their capacity as intellectual challenge, they are without precedent in the cultural history of mankind.

I mean, if 10 years from now, when you are doing something quick and dirty, you suddenly visualize that I am looking over your shoulders and say to yourself "Dijkstra would not have liked this," well, that would be enough immortality for me.

John von Neumann draws attention to what seemed to him a contrast. He remarked that for simple mechanisms, it is often easier to describe how they work than what they do, while for more complicated mechanisms, it is usually the other way around.

APL is a mistake, carried through to perfection.

There is very little point in trying to urge the world to mend its ways as long as that world is still convinced that its ways are perfectly adequate.