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

If in physics there's something you don't understand, you can always hide behind the uncharted depths of nature. You can always blame God. You didn't make it so complex yourself. But if your program doesn't work, there is no one to hide behind. You cannot hide behind an obstinate nature. If it doesn't work, you've messed up.

The computing scientist's main challenge is not to get confused by the complexities of his own making.

The use of COBOL cripples the mind; its teaching should, therefore, be regarded as a criminal offense.

Don't compete with me: firstly, I have more experience, and secondly, I have chosen the weapons.

... as a slow-witted human being I have a very small head and I had better learn to live with it and to respect my limitations and give them full credit, rather than to try to ignore them, for the latter vain effort will be punished by failure.

APL is a mistake, carried through to perfection.