This article deals the process of the philosophical development and transformation of ideas of Semyon Frank (1877–1950). At the beginning of the 20th century Frank, inspirited by Nietzsche, Neo-Kantians and Wilhelm Schuppe, claimed that metaphysics is not theoretical discipline, but only an expression of sentiments and passions. According to early Frank the object of metaphysics is not the world, but s e l f - c o n s c i o u s n e s s. Since 1908 Frank was influenced by Goethe and Bergson. In this connection he began to stress the value of intuition (or faith) in the process of cognition. As a consequence he elaborated a conception of All-unity (Absolute) contained all beings including subject of cognition. Contrary to Neo-Kantians the Russian philosopher in the latter period of his creation learnt about real existence of the object of cognition. The concluding paragraph compares epistemological views of Frank and Nicolai Hartmann.