“Triage,” Claudia Rankine’s new book, opens at a scene of inquisition. At a podium, under a spotlight, a theorist is asked a gloomy question by someone in the audience. “Toomuchness” is endemic to the times: “We were all struggling with varying degrees of powerlessness and capitulation,” Rankine writes. “I’d thought to take one of the floating mics and have the spotlight find me in the back of the auditorium,” Rankine writes. The theorist values speech, equating it with action; the narrator values quiet, viewing it as “a portal to the mystery of an interior life.”