In Nerval’s work, for example, the fantastic or phantasmagorical powers of the imagination come to spread on the ground of the dream which is not separated by the reality, on the contrary, it continues the reality where this one cannot move forward any more. The dream has under the feather of this romantic author a medical and clinical connotation, but also an aesthetic dimension. In other words, the dream is an underground relay between illness and reason, day and night, history and fiction. In fact, we attend in the case of Aurélia or Raoul Spifame, for example, an abolishment of the borders between reality, on one hand, and dream, on the other hand. In brief, it is simultaneously a lucid and hallucinatory dream which invade reality that the lecturer can discover in Nerval’s work.