Writer Nigel Nicolson caused a sensation with his book about his parents, “Portrait of A Marriage.” Now he’s back with a biography (for the Penguin Lives series) of Virginia Woolf, who was for a time his mother’s lover. Nicholson says Woolf invented the stream-of consciousness literary style, endured several bouts of madness, and died a suicide. And, we hear a rare clip of Virginia Woolf talking about writing.