Pavel Florensky - certainly the greatest Russian theologian of the last century - is now recognized as one of Russia's greatest polymaths. This volume is the first English translation of his rich and fascinating defense of Russian Orthodox theology. Originally published in 1914, the book is a series of twelve letters to a "brother" or "friend" who may be understood symbolically as Christ. Central to Florensky's work is an exploration of the various meanings of Christian love. He is perhaps the first modern writer to explore so-called "same-sex unions" as he describes the ancient Christian rites of the adelphopoiesis - the joining of male friends in chaste bonds of love. In addition, Florensky is one of the first thinkers of the twentieth century to develop the idea of the Divine Sophia, who has become one of the central concerns of feminist theologians.