From Robert Silverberg’s “Earthmen and Strangers” anthology, 1966: Damon Knight is a slender, soft-spoken man with a deceptively mild smile. He seems gentle and relaxed, but behind the tranquil exterior there seethes a fiercely active mind. Knight has served science fiction as an editor of magazines and anthologies, as a feared and respected critic, as a translator from the French, and as a lea...