Edsger Wybe Dijkstra

Table of contents

1 Edsger W. Dijkstra (1930 - 2002) 1.1 Verified 1.2 Attributed 1.3 Wrongly attributed 1.4 Web links

Edsger W. Dijkstra (1930 - 2002 )

Computer Scientist

Verified

• "The use of COBOL cripples the mind; its teaching should, therefore, be regarded as a criminal offence." (1968 )
  • Source: Used in How do we tell truths that might hurt? in Selected Writings on Computing:A Personal Perspective.

• "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." (1968 )
  • Source: Used in How do we tell truths that might hurt? in Selected Writings on Computing:A Personal Perspective.

• "FORTRAN, "the infantile disorder", by now nearly 20 years old, is hopelessly inadequate for whatever computer application you have in mind today: it is now too clumsy, too risky, and too expensive to use."
  • Source: Used in How do we tell truths that might hurt? in Selected Writings on Computing:A Personal Perspective.

• "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."
  • Source: Used in How do we tell truths that might hurt? in Selected Writings on Computing:A Personal Perspective.

• "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."
  • Source: Used in How do we tell truths that might hurt? in Selected Writings on Computing:A Personal Perspective.

• "Program testing can be used to show the presence of bugs, but never to show their absence!"
  • Source: Notes On Structured Programming, 1970, at the end of section 3, On The Reliability of Mechanisms. see EWD249 at http://www.cs.utexas.edu/users/EWD/ewd02xx/EWD249.PDF

• "Program testing can be a very effective way to show the presence of bugs, but is hopelessly inadequate for showing their absence."
  • Source: The Humble Programmer (EWD340). Same quote as above, but worded differently, and from another writing.

• "Besides a mathematical inclination, an exceptionally good mastery of one's native tongue is the most vital asset of a competent programmer."
  • Source: Used in How do we tell truths that might hurt? in Selected Writings on Computing:A Personal Perspective.

• "Simplicity is prerequisite for reliability."
  • Source: Used in How do we tell truths that might hurt? in Selected Writings on Computing:A Personal Perspective.

• "There are many different styles of composition. I characterize them always as Mozart versus Beethoven. When Mozart began to write at that time he had the composition ready in his mind. He wrote the manuscript and it was 'aus einem Guss' (casted as one). And it was also written very beautiful. Beethoven was an indecisive and a tinkerer and wrote down before he had the composition ready and plastered parts over to change them. There was a certain place where he plastered over nine times and one did remove that carefully to see what happened and it turned out the last version was the same as the first one."
  • Source: Denken als discipline a program from Dutch public TV station VPRO from April 10th, 2001 about Dijkstra, with many references, among other things Video (Broadband), Video, Transcript

• "... the question of whether Machines Can Think ... is about as relevant as the question of whether Submarines Can Swim."
  • Source: EWD898 - The threats to computing science

• "Programming is one of the most difficult branches of applied mathematics; the poorer mathematicians had better remain pure mathematicians."
  • Source: How do we tell truths that might hurt ?

• "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."
  • Source: EWD340

• "Elegance is not a dispensable luxury but a factor that decides between success and failure."
  • Source: EWD1284

Attributed

• "Computer Science is no more about computers than astronomy is about telescopes."

• "Do only what only you can do"

• "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."

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

• "The prisoner falls in love with his chains."

• "Teaching BASIC should be a criminal offense."

• "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."

• "When there were no computers programming was no problem. When we had a few weak computers, it became a mild problem. Now that we have gigantic computers, programming is a gigantic problem."

• "Why has elegance found so little following? Elegance has the disadvantage that hard work is needed to achieve it and a good education to appreciate it."

• "The required techniques of effective reasoning are pretty formal, but as long as programming is done by people that don't master them, the software crisis will remain with us and will be considered an incurable disease. And you know what incurable diseases do: they invite the quacks and charlatans in, who in this case take the form of Software Engineering gurus."

• "You must not give the world what it asks for, but what it needs."
• "We must not put mistakes into programs because of sloppyness, we have to do it systematical and with care."
• "I realized that my prior projects were just finger warm-ups. Now I have to tackle complexity itself. But it took long, before I had assembled the courage to do so."

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Wrongly attributed

• "GOTO statement considered harmful"
  • Source: From the title to a letter in CACM 11, 3 (March, 1968). However The original title of "A Case against the GO TO Statement" (EWD215, PDF here, ACM has its own copy online) was changed by the editor Niklaus Wirth, to speed up publication. Dijkstra explains it himself in EWD1308 (see near the end of the article). So not a quote, but an article title. Article by EWD, title change by Niklaus Wirth. Hope this clears things up.

Web links

• E. W. Dijkstra Archive - the manuscripts of Edsger W. Dijkstra
• Citations by Dutch public TV station VPRO
• EWDtjes -- scientific chain letters

See: list of people by name