Three "Apologetic Treatises against those Decrying the Holy Images" – These treatises were among his earliest expositions in response to the edict by the Byzantine Emperor Leo III, banning the worship or exhibition of holy images.
Fountain of Knowledge" or "The Fountain of Wisdom", is divided into three parts:
"Philosophical Chapters" (Kephalaia philosophika) – Commonly called 'Dialectic', deals mostly with logic, its primary purpose being to prepare the reader for a better understanding of the rest of the book.
"Concerning Heresy" (peri haireseon) – The last chapter of this part (Chapter 101) deals with the Heresy of the Ishmaelites. Differently from the previous 'chapters' on other heresies which are usually only a few lines long, this chapter occupies a few pages in his work. It is one of the first Christian polemical writings against Islam, and the first one written by a Greek Orthodox/Melkite.
"An Exact Exposition of the Orthodox Faith" (Ekdosis akribes tes orthodoxou pisteos) – a summary of the dogmatic writings of the Early Church Fathers, this third section of the book is known to be the most important work of John de Damascene, and a treasured antiquity of Christianity.