Piercing incisively and deeply into the nature of the overlapping of the material and mental realms. Aage Petersen uncovers the reciprocal relations between quantum physics and the concepts of metaphysics and epistemology, assessing the extent to which each has influenced the other. The author is eminently qualified to undertake this important work, which grew out of his close contact with Neils Bohr and his Copenhagen school during the years 1952-1962...