In the article one of the major aspects of ontology of Paul Tillich (1886- 1965), an outstanding German-American philosopher and theologian, the founder of current neo-liberal theology, philosopher of culture, - the problem of existence as an alienation is analyzed. The concept of alienation, which is dominant in the world, is described by the majority of trends of modern philosophy and Christian anthropology to both of which Tillich belonged. The majority of religious thinkers of XX century (not only Christian thinkers) have apprehended philosophical concept of alienation as a correlate of theological concepts of God-abandonness, creatureness and sinfulness.
The book is devoted to consideration in a popular form of evolution of one of the most debatable creations of the Western European metaphysics – the ontological evidence for God's existence or ontological argument. The idea of classical and non-classical arguments has allowed the author to analyses argument development as process of formation of the reflexive methodology, which is adequate for knowledge of the systems including free activity of the person. These are the problems constantly facing modern social sciences; therefore, despite the historical and philosophical direction of the book, the problems that are relevant to modern social and human sciences are under continued discussion. The book is primarily addressed to specialists in the field history of philosophy and methodology of social knowledge, philosophy and sociology of religion, and also to all who are interested in fundamental questions of classical metaphysics.