Abstract
Tertullian was the first to coin the Latin term trinitas for the description of the three divine entities in his doctrine of the Trinity. He translated the Greek term trias which was used in describing the Christian triad. Before Tertullian, Justin Martyr developed the Logos Christology and described the Christian Triad in terms of rank or order of its members. The term goes back to Pythagoras and can be found in many cultures as representing groupings of three divinities. Tertullian’s innovation was that he developed the concept of a triune God applied to the Christian myth and changed the meaning of the original term trias. Tertullian shows in his writings enormous erudition and knowledge of cultures and literatures of his time, a familiarity with Egyptian religion, and mystery religions, Greek as well as Egyptian. He found useful the Egyptian concept of the trinity for interpretation of the Christian biblical mythology and, at the same time, he explained it in metaphysical terms using the Middle Platonic Logos doctrine and the Stoic logical categories. His theory is based on the assumption of unity and unchangeability of the substance i.e., the spirit as the substance of God and the relative distinctiveness of the three members of the divinity.