Chapter 3 of Charles Dickens's A Tale of Two Cities (1859) is entitled 'The Night Shadows' and opens with reflections on night, sleep and its secrets:
'A wonderful fact to reflect upon, that every human creature is constituted to be that profound secret and mystery to every other. A solemn consideration, when I enter a great city by night, that every one of those darkly clustered houses encloses its own secret; that every room in every one of them encloses its own secret; that every beating heart in the hundreds of thousands of breasts there, is, in some of its imaginings, a secret to the heart nearest it! Something of the awfulness, even of Death itself, is referable to this. No more can I turn the leaves of this dear book that I loved, and vainly hope in time to read it all. No more can I look into the depths of this unfathomable water, wherein, as momentary lights glanced into it, I have had glimpses of buried treasure and other things submerged. It was appointed that the book should shut with a a spring, for ever and for ever, when I had read but a page. It was appointed that the water should be locked in an eternal frost, when the light was playing on its surface, and I stood in ignorance on the shore. My friend is dead, my neighbour is dead, my love, the darling of my soul, is dead; it is the inexorable consolidation and perpetuation of the secret that was always in that individuality, and which I shall carry in mine to my life's end. In any of the burial-places of this city through which I pass, is there a sleeper more inscrutable than its busy inhabitants are, in their innermost personality, to me, or than I am to them?
Picture credits: Sleeping Beauty by Edward Burne-Jones (top); photo titled 'Sleeping Dancer' sourced from here. Unfortunately I don't know anything more about the photographer, who seems to be called Matilde, but check out the site for some good pictures.