By Heart is a series in which authors share and discuss their all-time favorite passages in literature. See entries from Claire Messud, Jonathan Franzen, Amy Tan, Khaled Hosseini, and more. Doug McLeanWilliam Butler Yeats’ “The Lake Isle of Innisfree” is about the allure of an imagined refuge. The poem’s distressed urban speaker fantasizes about fleeing the city and retreating to an idyllic Irish island; his fervid mantra is “I will arise and go.” For Billy Collins, author of Aimless Love, poetry itself is that sanctuary, a place to seek peace when times are tough.