In his 72 years, Judge J. Harvie Wilkinson III of the U.S. Court of Appeals for the Fourth Circuit, who was raised in segregated Richmond, Virginia, acknowledges that he has seen much change, often for the better, including advances in the 1960s. But in his elegant new memoir, “All Falling Faiths: Reflections on the Promise and Failure of the 1960s,” he explains why today’s distemper was incubated in that “burnt and ravaged forest of a decade.”