Not sure whether this is the right place to discuss computers and programming in general: But Dijkstra's metaphor is suggesting, that while Beethoven learned by experiment and debugging compositions, Mozart did not have a need for reflection while writing down music ? The observation above sounds to me more as a difference between youthful enthousiasm (= allows few time for reflection but a lot for action) and old wisdom (= no risk taking but few action for the young). Also this difference has already been documented in Aristotele's Rethorics. It is of course difficult to transmit the characteristics of old age to young age, or vice versa. Furthermore about Dijkstra's quote on computers and telescopes which I like more. Telescopes are indeed not saying anything at all about the laws of the universe, as computers themselves don't say anything at all about complexity. But I wonder if we would have concepts as gravity or general relativity if we would have never had observed the movement of planets and light with telescopes. Equally, what can parallelity in computers teach us about the concept of monad ? I also find the approach of the designers of telescopes (= computer architects) interesting to understand parallel processes: http://view.eecs.berkeley.edu/wiki/Main_Page I think they use the name "dwarfs" for monads. PS I like the idea of a book "Hakell for Hackers" ___________________________________________________________ Telefonate ohne weitere Kosten vom PC zum PC: http://messenger.yahoo.de