Plotinus (205-270) is the most intense and powerful thinker in the context of late antique philosophy with a historically far-reaching influence. This book deals with some questions and solutions that are central to Plotin's philosophical theory: the spirit (nus) as an absolute reflection of being, in which truth, wisdom and beauty are founded in an absolute sense, the "true self" of man as the goal of his self-ascertainment, and the One itself, which proves to be the very ground for this movement.