“On Principles” is the first part of the “Experience of Christian Metaphysics” conceived by the author. “On Principles” is Karsavin’s central book, where he gives the basis of his system. The title, which coincides with the title of Origen's main work, helps to understand the nature of the book. Karsavin always wanted to develop his philosophy in the late antique and medieval tradition, hence the constant stylization of Karsavin’s texts as medieval. But the tradition that Karsavin has in mind is not the main path of Christian theology, but its marginal branches - the Christian Gnosticism of the Alexandrians, the free philosophizing of Gregory of Nyssa and Maximus the Confessor, the successors of this tradition in the West - Kuzanets, Boehme.