(Interview with Kent Beck by Niclas Nilsson, Floyd Marinescu on 25/01/2008)
programmers communicate with other people with their code, so it's not enough to just instruct a machine to do something that you need also to think about what will people read in what I write here, so it's programming more like a writer would write, than just thinking of a set of instructions for a machine.
the easy part of XP is practice related, but there is 3 legs on the stool: practices, values and principles... This gets back a little bit to some of my disenchantment with the direction of agile development in general, people are now asking the question: "How am I going to do agile development?" and agile development isn't a thing you do, it's an attitude, it's a set of personal values about responding to the real world, being open to the information that is there and being willing to do something about it.