The book “Shapeless Light”, published by Rev. Robert Boehle (O.C.D.) in 1987, is a classic work on the history of the East Syrian mystical tradition of the 7th–8th centuries. During this period in Mesopotamia, in the territory of modern South-Eastern Turkey, Iraq, South-Western Iran and Qatar, the monastic movement flourished, associated with the names of Sahdona, Dadisho of Qatar, Isaac of Nineveh, Simeon d-Taibute, John of Daliyat and Joseph Hazzayi. These mystical-ascetic writers accepted and developed the teachings of the Egyptian and Greek fathers about contemplation, deification, and the vision of divine light and formulated a number of provisions that anticipated the Palamite disputes of the 14th century. The publication is addressed to all those interested in the mystical-ascetic teachings of the Orthodox Church and Ancient Eastern Christian churches. In format PDF A4 retained publishing layout.