This week is the last post in the series on Isidore of Seville and his work on the many names of the God the Father, God the Son, God the Holy Spirit and the Trinity taken from his work titled “The Etymologies.” Once again, this work can be found completely free online here.
iv. The Trinity (De Trinitate)
The Trinity (Trinitas) is so named because from a certain three (tres) is made one (unum) whole, as it were a ‘Tri-unity’ (Triunitas) – just like memory, intelligence, and will, in which the mind has in itself a certain image of the divine Trinity. Indeed, while they are three, they are one, because while they persist in themselves as individual components, they are all in all. Therefore the Father, Son, and Holy Spirit are a trinity and a unity, for they are both one and three. They are one in nature (natura), three in person (persona). One because of their shared majesty, three because of the individuality of the persons. For the Father is one person, the Son another, the Holy Spirit another – but another person (alius), not another thing (aliud), because they are equally and jointly a single thing (simplex), immutable, good, and coeternal. Only the Father is not derived from another; therefore he is called Unbegotten (Ingenitus). Only the Son is born of the Father; therefore he is called Begotten (Genitus). Only the Holy Spirit proceeds from the Father and the Son; therefore it alone is referred to as ‘the Spirit of both the others.’
For this Trinity some names are appellative (appellativus), and some are proper (proprius). The proper ones name the essence, such as God, Lord, Almighty, Immutable, Immortal. These are proper because they signify the very substance by which the three are one. But appellative names are Father and Son and Holy Spirit, Unbegotten and Begotten and Proceeding. These same are also relational (relativus) because they have reference (referre, ppl. relatus) to one another. When one says “God,” that is the essence, because he is being named with respect to himself. But when one says Father and Son and Holy Spirit, these names are spoken relationally, because they have reference to one another. For we say ‘Father’ not with respect to himself, but with respect to his relation to the Son, because he has a son; likewise we speak of ‘Son’ relationally, because he has a father; and so ‘Holy Spirit,’ because it is the spirit of the Father and the Son. This relationship is signified by these ‘appellative terms’ (appellatio), because they have reference to one another, but the substance itself, in which the three are one, is not thus signified.
Hence the Trinity exists in the relational names of the persons. Deity is not tripled, but exists in singleness, for if it were tripled we would introduce a plurality of gods. For that reason the name of ‘gods’ in the plural is said with regard to angels and holy people, because they are not his equal in merit. Concerning these is the Psalm (81:6 Vulgate), “I have said: You are gods.” But for the Father and Son and Holy Spirit, because of their one and equal divinity, the name is observed to be not ‘gods’ but ‘God,’ as the Apostle says (I Corinthians 8:6): “Yet to us there is but one God,” or as we hear from the divine voice (Mark 12:29, etc.), “Hear, O Israel: the Lord thy God is one God,” namely inasmuch as he is both the Trinity and the one Lord God.
This tenet of faith concerning the Trinity is put in this way in Greek: ‘one οὐσία,’ as if one were to say ‘one nature’ (natura) or ‘one essence’ (essentia); ‘three ὑποστάσεις,’ which in Latin means “three persons” (persona) or “three substances” (substantia). Now Latin does not speak of God properly except as ‘essence’; people say ‘substance,’ indeed, but metaphorically, for in Greek the term ‘substance’ actually is understood as a person of God, not as his nature.