In Wanderlust, I wrote, “This history of walking is an amateur history, just as walking is an amateur act. To use a walking metaphor, it trespasses through everybody else’s field—through anatomy, anthropology, architecture, gardening, geography, political and cultural history, literature, sexuality, religious studies—and doesn’t stop in any of them on its long route. For if a field of expertise can be imagined as a real field—a nice rectangular confine carefully tilled and yielding a specific crop—then the subject of walking resembles walking itself in its lack of confines.”
http://believermag.com/issues/200909/?read=interview_solnit