“The most tremendous thing granted to humanity is choice, freedom”: so writes Kierkegaard in his Journal, and such also is the central conviction that inspires this present book. Its theme is “the glorious liberty of the children of God” (Rom. 8:21)—a liberty only to be attained through asceticism. Christos Yannaras has not attempted to write a systematic treatise on ethics, for he believes that it is impossible, within a genuinely Orthodox context, to provide a “system” of moral conduct.