Gen X underdog heartthrob, graphic novelist, Shakespearean actor, foil to Julie Delpy, and muse to Richard Linklater—Ethan Hawke wears many hats. Whether coming of age in “Dead Poets Society,” fighting to stay on the straight and narrow in “Training Day,” or aging before our eyes in “Boyhood,” Hawke is an inveterate entertainer. In last year’s “Blue Moon,” his ninth movie with Linklater, which earned him his fifth Academy Award nomination, he plays the lyricist Lorenz Hart, embodying a bitter and jealous endurer of humiliations, in a performance that Richard Brody called “exalted and startling.” He now stars in the TV crime drama “The Lowdown,” and a new film, “The Weight,” co-starring Russell Crowe, about a Depression-era road gang. He spoke with Emily Nussbaum, the magazine’s theatre critic, at the twenty-seventh annual New Yorker Festival.