Carl Gustav Jung (1875-1961), Swiss physician and pioneer of psychoanalysis, is one of the great thinkers of the 20th century. He remains largely unknown in France, even though his ideas have had a profound influence on our contemporary culture and even though it was him who coined many revolutionary concepts, such as synchronicity, the collective unconscious, archetypes and complexes. He is, along with Spinoza, one of the authors who have had the greatest impact on me, and he has had a decisive impact on my vision of the world and of myself. That is why I have put so much effort into making his visionary thought accessible to a wide public, bridging the gap between psychology and quantum physics, showing how much the human being needs meaning and a symbolic or spiritual life in order to develop fully and profoundly. This conviction will lead Jung away from Freud and will lead him to experience and elaborate his "individuation process" an extraordinary inner journey in which each of us learns to make our conscious and unconscious dialogue in order to become fully ourselves and to reach a feeling of unity and deep joy. It is to this fascinating journey towards oneself that I wanted to invite the reader, to the discovery of one of the thinkers who I believe has gone the furthest in the understanding of the human being and the meaning of his existence.