is the Logos, or reason, of God, one is certainly elevating a mode of relation to Personhood.How is The Logos "a mode of relation"?
Logos does not mean "reason of God". And even if it did, wouldn't it be an attribute rather than a personified "mode of relation"?
The well known Theologian who introduced us to the Logos wrote:
"In the beginning was the Logos, and the Logos was with God and the Logos was God....." (John 1:1)
How is he describing "a mode of relation"? He is actually describing the relationship between the Logos and God (which he certainly does not personify).
The word 'logos' means 'Principle of order and knowledge' in the Greek of the day.
Since God is one simple divine essence, distinguishing marks within Him are only by opposite modes of relation. For example, the Father has a relation to the Son, and He has a relation to the Spirit. However, He does not have opposite relations to these. If He did, the Father would be two persons, whereas He is one person. He has the same mode of relation to the Son as He has to the Spirit: That both the Son and the Spirit are related to Him as being produced by Him.
Three distinguishing marks characterize any act of production: Efficient cause (that which produces), material cause (the matter out of which the product is produced), and formal term (the form it takes upon production).
The Son and the Spirit are not distinguished from one another by material cause, because they have no matter. Nor are they distinguished from one another by formal term, because they have the same form: The Divine Essence. Therefore, they are distinguished by efficient cause. Both are produced by the Father, so in order to be distinguished by efficient cause one of them must be produced by both the Father and another person of the Trinity.
There are three modes of relation within a living being: The sensible principle, by which matter act upon it, The appetitive principle, by which it is drawn towards its natural good, and the rational principle, by which it produces a similitude in the mind of being (this similitude being knowledge).
God has no sensible principle, because matter cannot act on Him.
The opposite mode of relation which distinguishes Father from Son is that of the rational principle: Paternity-Filiation.
This leaves the appetitive principle as the remaining opposite mode of relation to distinguish Spirit from Father and Son. The opposite relations here are Spiration-Procession.
Both knowledge and appetite are rooted in being, and it is therefore correct to say that the Spirit proceeds From the Father
It is through knowledge that the knower desires what is known, and it is therefore also correct to say that the Spirit proceeds From the Father through the Son
One must have knowledge of a thing in order to desire it (Bill cannot spirate a desire for Hamburgers, and a desire for Hamburgers cannot proceed from him, if Bill has no conception of what a Hamburger is). For this reason the Spirit cannot be distinguished from the Father and the Son simply, but only from the Father and the Son collectively, and it is therefore also correct to say that the Spirit proceeds From the Father and the Son
Re Peter J: Aquinas' 'Treatise on the Most Holy Trinity' in the Summa Theologiae