Quotes from Edsger W. Dijkstra

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

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

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

The argument against recursive procedures was always an efficiency argument: non-re-entrant code could be executed so much more efficiently. But with the advent of multiprogramming another need for felxible storage allocation has emerged. And if there are still machines in which the use of recursive routines is punished by too heavy a penalty, then I would venture the opinion that the structure of such a machine should now be called somewhat old-fashioned.

The teaching of BASIC should be rated as a criminal offence: it mutilates the mind beyond recovery.