With the terms «visionary» and «despot», the author seeks to circumscribe the multilayered personality of Gustav Mahler. Opening up a terra incognita, he draws a comprehensive map of the various aspects of Mahler's inner biography: his unshakable belief in the «sacredness of musical art» and strongly developed sense of mission, his double life as conductor and composer, his inexorability and refusal to compromise vis-à-vis himself and others, his discomfort with the world in which he lived, the complex facets of his psyche and his enormous energy potential. The result is the disclosure of new and unexpected connections between Mahler's personality and his oeuvre.