 According to Simon, dreams are produced by the common sense from images (idola) sent to it by the phantasia. Dreams, however, have different origins, stemming either from the human being himself or from celestial bodies. If from the human being, they either stem from his body or soul. Dreams stem from someone’s body when the powers of a bodily organ are affected by the choleric or phlegmatic humors (two of the four bodily fluids in Hippocratic medical doctrine). When the organs are thus affected, the phantasia forms images that are in agreement with those fluids and sends them to the common sense. A person can then dream that she is on fire, for example, if the choleric humor is dominant. Dreams stem from someone’s soul when during sleep the soul is affected by a memory, e.g., of a friend who is far away. A person can then have a melancholic dream about her friend.