St Gregory Palamas, a fourteenth-century Byzantine saint and Church Father, incorporated traditional Eastern monastic spirituality into a comprehensive theological vision. His understanding of hesychasm, the monastic movement centered on solitude and unceasing prayer, is grounded in an incarnational theology: When spiritual joy comes to the body from the mind, it suffers no diminution by this communion with the body, but rather transfigures the body, spiritualizing it rejecting all evil desires of the flesh, it no longer weighs down the soul but rises up with it, the whole man becoming spirit, as it is written: 'He who is born of the Spirit is spirit' (John 3:6-8). Triads 11, 2.9 This richly documented and lavishly illustrated study of Orthodox spirituality traces the development of 'Orthodox mysticism' from the desert fathers through the patristic tradition to Byzantine hesychasm and its heritage in Russian monasticism. It shows how the work of Palamas transcends the limits of one school of spirituality and renews in its deepest essence the life of the Christian Mystery.