Billy Collins on his selection: I chose poems from William Matthews (1942-1997) and Thomas Lux (1946-2017) because I wanted to honor two fallen soldiers who fought for an increase of beauty and truth in the world, who also knew that a good poem must at least be a series of good lines—that is, they found their way to the end of a poem one line at a time. In their own different ways and with highly different voices, they both understood the importance of broad humor and subtle ironies in freeing a poem from the claustrophobia of purely autobiographical designs. All poems are autobiographical in that it takes a human being to write one. But these two faced the world, not the mirror, when they wrote, and thus followed the advice that “poems should at least be interesting.” Plus, it’s no secret that they were both irreplaceable pals of mine—as well as teachers by the distinctive example of their best work.