In passing I draw attention to another English expression which often occurs in Dutch texts: "the real world". In Dutch - and I am afraid not in Dutch alone - its usage is almost always a symptom of a violent anti-intellectualism.

Progress is possible only if we train ourselves to think about programs without thinking of them as pieces of executable code.

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.

Testing shows the presence, not the absence of bugs.

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

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

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.