The doctrine of the “filioque”, a settled notion in Western theology, is the idea that in the economy of the Holy Trinity the Holy Spirit proceeds from the Father and the Son. This understanding of the Godhead is found chiefly in the writings of St. Augustine, but is also present in other Patristic writers…notably Hilary of Poitiers. Much of the reasoning behind the filioque was the preservation of the divinity of the Son against the Arian heresy. For, if the Holy Spirit proceeds from the Father and the Son, then it can’t be the case that the Son is finite (i.e. created). The Son must likewise be eternal, and therefore Divine.
This is but a bare sketch of the doctrine. The filioque, however well intentioned, is also mistaken. It is mistaken because it only confuses our understanding of the Godhead. What’s more, it’s not necessary for the refutation of Arianism. The Eastern understanding that the Son proceeds from the Father alone is a sufficient reason for rejecting the teachings of Arius.
The Eastern view is that the Father, alone, is the Source of the Godhead. In other words, the Father is the One who secures the deity of the Son and Holy Spirit by virtue of His own paternity. He is the Father because He begets the Son and sends the Holy Spirit. Those are His paternal prerogatives. They are why He is the fountainhead of Deity. But let’s take these two propositions in turn:
“He is Father because He begets the Son”
Because the Father–qua father–is eternal, there could never be a time in which He wasn’t “Father”. But what is He father of? It can’t be the case that He is Father by virtue of creation, since creation is finite. If it were the case that the Father is rightly known to be “father” by virtue of finite creation, then there was a time in which He wasn’t actually a father. That can’t be right because, as we said, the Father–qua father–is eternal. Therefore, His paternity is assured because something else is eternal– namely the Son. The Son is also God because without Him the Father is not a father. Or, as scripture says
“Whoever denies the Son does not have the Father either; he who acknowledges the Son has the Father also” (1 John 2:23)
So we see that the Father is the Father because He eternally “begets” the Son. However, we must also treat of our second proposition:
“He is the Father because He sends the Holy Spirit”
The Divine Paternity also rests on the Father having “sent” the Holy Spirit alone. To say that the Holy Spirit proceeds from the Father and the Son is to blur the distinction between the Father and the Son by ascribing the Paternity of God to both. How else are we to distinguish Father from Son otherwise? Moreover, the filioque introduces an imbalance in the Holy Trinity because it leaves little reason for affirming the deity of the Holy Spirit. If the Father is God because He begets the Son……and the Son is God because He participates with the Father in sending the Holy Spirit……whence the divinity of the Holy Spirit? The Spirit neither “sends” nor “begets”. So what distinguishes Him as Divine? If it’s simply because He is sent by the Father and the Son, then the establishment of Divinity does not require active participation in either “sending” nor “begetting”. Why should it then be required that the Son “send” in order for Him to be recognized as Divine? In other words, the filioque’s attempt to rescue the Son from the Arians leaves the Holy Spirit without the same commendation as the Son. Therefore, the Divinity of the Holy Spirit becomes doubtful. But if being “sent” is good enough to secure the Divinity of the Holy Spirit, isn’t being “begotten” by the Father enough to secure the Divinity of the Son? What’s sauce for the goose is sauce for the gander.
The Son is Divine because He was begotten of the Father from eternity. The Holy Spirit is Divine because He was sent by the Father from eternity. The Father is Divine because He, in His Paternal prerogatives, begets the Son and sends the Holy Spirit from eternity. By allowing the Father to be the Source of the Holy Trinity, the Divinity of all the Persons of the Godhead is established.