I came across a book which discusses U2’s philosophy in the framework of postmodernism. It talks about U2 being a band trying to make sense of living in a hopeless world, and explained in terms of philosophical arguments. As for people who run away at the very mention of philosophy, this is a must read as it deconstructs and shatters your image of what philosophy stands for.
U2 and Philosophy – how to decifer an atomic band
Edited by Mark A. Wrathall