Respuesta :
When the narrator mentions that "Whispering lunar incantations/ Dissolve the floors of memory/ and all its clear relations,/ Its divisions and precisions", we can deduce that he is lost in thought, because some key words indicate so. The floor of his memory and its divisions and precisions are all dissolved by the incantations, meaning they are no more, they disappeared. But, as he continues, a single phrase "Midnight shakes the memory" confirms more clearly the narrator is lost in thought.