What is the theme in The Portable Beat Reader by Various?

Spontaneity is a theme in the book. The Beats pride themselves on being spontaneous and see spontaneity as part of a person being true to who they really are. For a person not to act on his spontaneous desires is to give in to the rules of society and become "square." Commenting on the Beat Generation, Norman Mailer writes that their morality consisted purely in doing what they wanted to do when they wanted to do it, which is precisely what the Beats thought of as being spontaneous.