Dreams have a privileged status among all the images. They do not depend on our will and appear to give evidence of the spontaneous eruption in our life of a power that is beyond us. Their most remarkable characteristic is that they make us believe they contain a mystery, that they open a door onto the reverse side of things, revealing to us an enigma to which we must find the key. The interpretations of dreams may differ, but everyone concedes that they have a power of transcendence with regard to the world of the wake. It is through dreams that the divine power has most frequently chosen to appear to its elected. The signs of dreams (if not of the other images of night, the stars) were considered when the future was to be foretold. But dreams, certainly also, restore to us a past long since effaced from our memory, dreams betray our most secret desires, ignored even by our conscience, and it is hence on dreams that we rely to discover the hidden motivations of our aberrant behaviour. In dreams things speak to us from a distance, people absent or even dead communicate with us; how many friends and lovers, whom life has separated, find each other every night and experience what Gérard de Nerval calls a second life? We pronounce the word “dream” when we want to describe an event that has astonished us, delighted us, and fulfilled us beyond what we would have dared to hope.