F. Nietzsche is known as an opponent of the Western Platonic Christian ethical tradition. Less known is his contribution in noetics and axiology, as his commentaries on those problems remained unpublished during his lifetime, although more attention was paid by him to the problem of Truth than to that of morals. In these works Nietzsche revaluates the concept of the Absulute Truth as the ultimate source of old values, i. e. of the „ascetic ideal“. The paper shows Nietzsche’s coming to terms with the Platonic ideal as the source of the absolute morality and with some representative noetic conceptions. It deals also with his conception of relative truth, based on the fundamental probabilities and on an inspirative theory of perspectivity revived for example in Ortega у Gasset’s philosophy and in postmodernism.