Quotes About Dijkstra

Seibel: There's a Dijkstra quote about how you can't prove by testing that a program is bug-free, you can only prove that you failed to find any bugs with your tests. But it sort of sounds the same way with a proof-you can't prove a program is bug-free with a proof-you can only prove that, as far as you understand your own proof, it hasn't turned up any bugs.

I don't know how many of you have ever met Dijkstra, but you probably know that arrogance in computer science is measured in nano-Dijkstras.

Mentally mutilated potential programmers beyond hope of regeneration.

Dijkstra once said, "Testing shows the presence, not the absence, of bugs." In other words, a program can be proven incorrect by a test, but it cannot be proven correct. All that tests can do, after sufficient testing effort, is allow us to deem a program to be correct enough for our purposes.

Dijkstra realized that these "good" uses of goto corresponded to simple selection and iteration control structures such as if/then/else and do/while. Modules that used only those kinds of control structures could be recursively subdivided into provable units.

The problem that Dijkstra recognized, early on, was that programming is hard, and that programmers don't do it very well.

I don't know how many of you have ever met Dijkstra, but you probably know that arrogance in computer science is measured in nano-Dijkstras.

In the software business there are many enterprises for which it is not clear that science can help them; that science should try is not clear either.

A popular saying at King Vizimir's court held that if Dijkstra states it is noon yet darkness reigns all around, it is time to start worrying about the fate of the sun.

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

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

the automatic computer confronts us with a radically new intellectual challenge that has no precedent in our history. Of course software has become even more complex since 1989, and Dijkstra's ratio of 1 to 109could easily be more like 1 to 1015 today.

Dijkstra pointed out that no one's skull is really big enough to contain a modern computer program (Dijkstra 1972), which means that we as software developers shouldn't try to cram whole programs into our skulls at once; we should try to organize our programs in such a way that we can safely focus on one part of it at a time.