A controversial issue of public debate during the recent years, esotericism can be described as the search for an absolute but hidden knowledge that people claim to access through mystical vision, the mediation of higher beings, or personal experience. In Western cultural history these claims often led to conflicts with more established forms of scriptural religions and with reductionist interpretations in science and philosophy. In this highly readable book Kocku von Stuckrad describes the impact of esoteric currents from antiquity to the present and pursues the continuities and breaks in a tradition that significantly influenced the formation of modernity. When Hermes Trismegistos reveals wisdom of an absolute quality, the unveiling of hidden knowledge in Jewish Kabbalah is transformed by Christians, Renaissance thinkers speak of an 'eternal philosophy,' or when in the 'New Age' people try to get in contact with a source of superior understanding--in every case the dynamic of concealment and revelation is at stake and the ways this hidden knowledge can be made accessible for human curiosity.