In the late fourth century, the early Christian monk and author Evagrius Ponticus wrote his magnum opus in Greek—entitled Kephalaia Gnostika (“Gnostic Chapters”)—a spiritual treatise on ascetic contemplation and unity with God. After Evagrius’ death, however, his theology attracted controversy, and many of his writings were suppressed or destroyed. As a result, complete copies of this important work principally survived only in Syriac translations and an Armenian adaptation, until the recent discovery of two Arabic copies at the so-called Monastery of the Syrians in Egypt. The present volume represents the first-ever critical edition and translation of the Kephalaia Gnostika in that language.