Heine’s poem ‘Still ist die Nacht, es ruhen die Gassen’ (‘The night is still, the streets are dumb’), written in the early 1820s, describes a nocturnal encounter between the poet and his double. The poet returns to stand under the window of the house where his beloved once lived, only to find his double on duty in his place. To the poet, the double’s sighs and hand-wringing seem to be a mocking...