Read the passage from "Ode on a Grecian Urn." Fair youth, beneath the trees, thou canst not leave Thy song, nor ever can those trees be bare; Bold Lover, never, never canst thou kiss, Though winning near the goal—yet, do not grieve; She cannot fade, though thou hast not thy bliss, For ever wilt thou love, and she be fair! The word from the passage that best defines the topic is