Edsger Dijkstra Quotes

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

The question of whether computers can think is like the question of whether submarines can swim.

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

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

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

The purpose of abstraction is not to be vague, but to create a new semantic level in which one can be absolutely precise.

Simplicity and elegance are unpopular because they require hard work and discipline to achieve and education to be appreciated.

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

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

Teaching COBOL ought to be regarded as a criminal act.

Perfecting oneself is as much unlearning as it is learning.

Too few people recognize that the high technology so celebrated today is essentially a mathematical technology.

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.

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

Besides a mathematical inclination, an exceptionally good mastery of one's native tongue is the most vital asset of a competent programmer.

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

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

We must be very careful when we give advice to younger people; sometimes they follow it!

Beware of "the real world". A speaker's apeal to it is always an invitation not to challenge his tacit assumptions.

Mathematicians are like managers - they want improvement without change.

Programming in Basic causes brain damage.

Are you quite sure that all those bells and whistles, all those wonderful facilities of your so called powerful programming languages, belong to the solution set rather than the problem set?

When building sand castles on the beach, we can ignore the waves but should watch the tide.

If you want more effective programmers, you will discover that they should not waste their time debugging, they should not introduce the bugs to start with.

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

Testing shows the presence, not the absence of bugs.

Probably I am very naive, but I also think I prefer to remain so, at least for the time being and perhaps for the rest of my life.

Thanks to the greatly improved possibility of communication, we overrate its importance. Even stronger, we underrate the importance of isolation.

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

It used to be the program's purpose to instruct our computers; it became the computer's purpose to execute our programs.

I don't need to waste my time with a computer just because I am a computer scientist.

Production speed is severely slowed down if one works with half-time people who have other obligations as well. This is at least a factor of four; probably it is worse.

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

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.

A programming language is a tool that has profound influence on our thinking habits.

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.

I would therefore like to posit that computing's central challenge, how not to make a mess of it, has not yet been met.

APL is a mistake, carried through to perfection.

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

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.

Beauty is our business.

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

Aim for brevity while avoiding jargon.

There should be no such thing as boring mathematics.

Thank goodness we don't have only serious problems, but ridiculous ones as well.

The art of programming is the art of organizing complexity.

In the good old days physicists repeated each other's experiments, just to be sure. Today they stick to FORTRAN, so that they can share each other's programs, bugs included.

Much of the excitement we get out of our work is that we don't really know what we are doing.

Industry suffers from the managerial dogma that for the sake of stability and continuity, the company should be independent of the competence of individual employees.

The tools we use have a profound and devious influence on our thinking habits, and therefore on our thinking abilities.