The Fount of Knowledge is divided into three categories:

  1. “Philosophical Chapters” (Kephalaia philosophika) – “With the exception of the fifteen chapters that deal exclusively with logic, it has mostly to do with the ontology of Aristotle. It is largely a summary of the Categories of Aristotle with Porphyry’s “Isagoge” (Eisagoge eis tas kategorias). It seems to have been John Damascene’s purpose to give his readers only such philosophical knowledge as was necessary for understanding the subsequent parts of the “Fountain of Wisdom”.
  2. “Concerning Heresy” (Peri aipeseon) – “Little more than a copy of a similar work by Epiphanius, brought up to date by John Damascene. The author indeed expressly disclaims originality except in the chapters devoted to Islamism, Iconoclasm, and Aposchitae. To the list of eighty heresies that constitute the “Panarion” of Epiphanius, he added twenty heresies that had sprung up since his time. In treating of Islamism he vigorously assails the immoral practices of Mohammed and the corrupt teachings inserted in the Koran to legalize the delinquencies of the prophet.”
  3. “An Exact Exposition of the Orthodox Faith” (Ikdosis akribes tes orthodoxou pisteos) – “The third book of the “Fountain of Wisdom”, is the most important of John Damascene’s writings and one of the most notable works of Christian antiquity. Its authority has always been great among the theologians of the East and West. Here, again, the author modestly disavows any claim of originality — any purpose to essay a new exposition of doctrinal truth. He assigns himself the less pretentious task of collecting in a single work the opinions of the ancient writers scattered through many volumes, and of systematizing and connecting them in a logical whole.2

In his passage on Concerning Heresies, his section on the superstition of the Ishmaelites is considerably longer than most. One reason for this attention could be his prolonged battles against iconoclasm, in which the influence of Islam was a significant factor. The following are selected sections from his passage on Islam.

Another depiction of Muhammad in hell for the sin of heresy. He is rendering his body as he rendered the Body of Christ. MS. Holkham misc. 48, p. 42, Bodleian Library in Oxford, England.

 

1. Muhammed devised his own heresy

“There is also the superstition of the Ishmaelites which to this day prevails and keeps people in error, being a forerunner of the Antichrist. They are descended from Ishmael, [who] was born to Abraham of Agar, and for this (More)