Everyone knows that the light of the stars needs a very long time to reach us; sometimes we perceive it after the star itself has disappeared. This gap between the star as a virtual source and its perception by us, this non-simultaneity, is an inescapable part of the illusion of the world, the absence at the heart of the world that constitutes the illusion. And again, this distortion is beneficial. For the simultaneous perception of the light of all the stars would be equivalent to an absolute daylight, and this would be unbearable for us. All the energy of life proceeds from this vital alternation of day and night, and more generally, from this vital mediation. Illusion is the general rule of the universe; reality is but an exception.