Ghosts appeared in Homer 's Odyssey and Iliad , in which they were described as vanishing "as a vapor, gibbering and whining into the earth". Homer's ghosts had little interaction with the world of the living. Periodically they were called upon to provide advice or prophecy, but they do not appear to be particularly feared. Ghosts in the classical world often appeared in the form of vapor or smoke, but at other times they were described as being substantial, appearing as they had been at the time of death, complete with the wounds that killed them. 
Joseph Conrad uses a doppelganger theme in his short story “ The Secret Sharer ”. In the story, “Laggatt”, ex-skipper of a ship, acts as a doppelganger of “The Captain”. “The Captain” discovers “Laggatt” swimming in the sea naked. He helps him come on board and gives him his clothes to wear. Both have similarities as well as dissimilarities. “Laggatt” who is full of calmness and self-confidence helps “The Captain” to get rid of his uncertainty and undue apprehensions. In fact, “Laggatt” is other self of “The Captain” that he has failed to discover until then.