Authorial Intent is Bostonist's wrapup of readings in the area. All events are free unless otherwise noted. Thursday, December 6 Greil Marcus, The Shape of Things to Come: Prophecy and the American Voice, Brookline Booksmith, 7:00 pm Greil Marcus goes in search of the American spirit and finds it in Philip Roth, David Lynch, David Thomas of Pere Ubu, and other unpredictable sources. The Village Voice writes that Marcus' latest "basks in the possibilities of......