"La Belle Dame sans Merci" is one of Keats's most beloved poems and one of the few important works that seems to evade the kind of critical argumentation invoked by the odes and long poems. Typical of critics' magnanimity toward the ballad is T. Hall Caine's 1882 assessment of the poem as the "loveliest [Keats] gave us." He writes that the ballad is "wholly simple and direct, and informed throughout by a reposeful strength. In all the qualities that rule and shape poetry into unity of form, this little work strides, perhaps, leagues in advance of 'Endymion,'" one of Keats's most noted poems. Caine further argues that the ballad's strength comes from the poet's ability to "(move) through an atmosphere peculiar to poetry, lacing and interlacing . . . combinations of thought and measure, (and) incorporating . . . meaning with . . . music." In a 1913 essay, Mary de Reyes notes Keats's fascination with...