Programming is one of the most difficult branches of applied mathematics; the poorer mathematicians had better remain pure mathematicians.

I mentioned the non-competitive spirit explicitly, because these days, excellence is a fashionable concept. But excellence is a competitive notion, and that is not what we are heading for: we are heading for perfection.

Simplicity is prerequisite for reliability.

About the use of language: it is impossible to sharpen a pencil with a blunt axe. It is equally vain to try to do it with ten blunt axes instead.

The ability of discerning high quality unavoidably implies the ability of identifying shortcomings.

The question of whether a computer can think is no more interesting than the question of whether a submarine can swim.

Program testing can be used to show the presence of bugs, but never to show their absence!

The lurking suspicion that something could be simplified is the world's richest source of rewarding challenges.

Elegance is not a dispensable luxury but a factor that decides between success and failure.

There should be no such thing as boring mathematics.

Mathematicians are like managers - they want improvement without change.

Programming is one of the most difficult branches of applied mathematics; the poorer mathematicians had better remain pure mathematicians.

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

Teaching to unsuspecting youngsters the effective use of formal methods is one of the joys of life because it is so extremely rewarding.

Why has elegance found so little following? That is the reality of it. Elegance has the disadvantage, if that's what it is, that hard work is needed to achieve it and a good education to appreciate it.

Computer science is no more about computers than astronomy is about telescopes.

Perfecting oneself is as much unlearning as it is learning.

The students that, like the wild animal being prepared for its tricks in the circus called "life", expects only training as sketched above, will be severely disappointed: by his standards he will learn next to nothing.

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.

The traditional mathematician recognizes and appreciates mathematical elegance when he sees it. I propose to go one step further, and to consider elegance an essential ingredient of mathematics: if it is clumsy, it is not mathematics.

APL is a mistake, carried through to perfection. It is the language of the future for the programming techniques of the past: it creates a new generation of coding bums.

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

Object-oriented programming is an exceptionally bad idea which could only have originated in California.

Aim for brevity while avoiding jargon.

It is practically impossible to teach good programming to students that have had a prior exposure to BASIC: as potential programmers they are mentally mutilated beyond hope of regeneration.

The competent programmer is fully aware of the limited size of his own skull. He therefore approaches his task with full humility, and avoids clever tricks like the plague.

Many mathematicians derive part of their self-esteem by feeling themselves the proud heirs of a long tradition of rational thinking; I am afraid they idealize their cultural ancestors.

The students that, like the wild animal being prepared for its tricks in the circus called 'life', expects only training as sketched above, will be severely disappointed: by his standards he will learn next to nothing.

Mathematicians are like managers they want improvement without change.

If debugging is the process of removing software bugs, then programming must be the process of putting them in.

If we wish to count lines of code, we should not regard them as lines produced but as lines spent.

As I say, there was this movement to try to bring philosophers and mathematicians together into an organization where they would talk to each other. An organization wasn't effective unless you had a journal. That's about all I know.

Mathematicians are born, not made.

As far as I know, only a small minority of mathematicians, even of those with Platonist views, accept the idea that there may be mathematical facts which are true but unknowable.

Therefore I would not have it unknown to Your Holiness, the the only thing which induced me to look for another way of reckoning the movements of the heavenly bodies was that I knew that mathematicians by no means agree in their investigation thereof.

Mathematicians may flatter themselves that they possess new ideas which mere human language is as yet unable to express.

It may be true, that men, who are mere mathematicians, have certain specific shortcomings, but that is not the fault of mathematics, for it is equally true of every other exclusive occupation.

Mathematicians aren't satisfied because they know there are no solutions up to four million or four billion, they really want to know that there are no solutions up to infinity.

The greatest mathematicians, as Archimedes, Newton, and Gauss, always united theory and applications in equal measure.

Pure mathematicians just love to try unsolved problems - they love a challenge.

The greatest problem for mathematicians now is probably the Riemann Hypothesis.

Mathematics is written for mathematicians.

First rate mathematicians choose first rate people, but second rate mathematicians choose third rate people.

Abel has left mathematicians enough to keep them busy for 500 years.

Mathematicians have tried in vain to this day to discover some order in the sequence of prime numbers, and we have reason to believe that it is a mystery into which the human mind will never penetrate.

Mathematicians are like managers - they want improvement without change.

The truth has never been of any real value to any human being - it is a symbol for mathematicians and philosophers to pursue. In human relations kindness and lies are worth a thousand truths.

For example, the philosophers who were interested in logic were probably rather logical for mathematicians. But the ASL got us together, so we could talk to each other and publish in the same journal.

The only thing that might have annoyed some mathematicians was the presumption of assuming that maybe the axiom of choice could fail, and that we should look into contrary assumptions.