Couple of examples:
Brian W. Kernighan {l Wrote}:Everyone knows that debugging is twice as hard as writing a program in the first place. So if you're as clever as you can be when you write it, how will you ever debug it?
Ken Thompson {l Wrote}:No amount of source-level verification or scrutiny will protect you from using untrusted code.
Dennis Ritchie {l Wrote}:When I read commentary about suggestions for where C should go, I often think back and give thanks that it wasn't developed under the advice of a worldwide crowd.
Rob Pike {l Wrote}:Object-oriented design is the roman numerals of computing.
Tom Duff {l Wrote}:Don't use hands to do things that can be efficiently done by the computer.
Everybody feel free to post more quotes.