St Isaac of Nineveh (7th c.), or Isaac the Syrian, is renowned for his spiritual writings. After only five months as bishop of Nineveh, he returned to a life of solitary stillness in the desert of modern-day Iran. His Spiritual Homilies (homilies 1-6 in PPS 11) quickly became treasured throughout the Christian world, not only inspiring monastic and spiritual life through the ages, but influencing culture more broadly, as in the works of Dostoevsky. Yet...