And from the Son
The Filioque clause, comes from the Latin phrase which means “and from the Son” was added in the 6th century. This was not in the original creed as written in 325 in Nicaea or 381 in Constantinople. This was officially incorporated into the liturgical practice of the Latin speaking churches in the West (Centered around Rome) in 1014. Although this was not the sole reason for the East and the West to separate, it was a piece of the puzzle. Eventually, after failed attempts to unite, the East and the West schism happened in 1054. This is where we get eastern orthodoxy and western orthodoxy (known as Roman catholic). Two major arguments were made by the ‘Patriarchs’ (elders) of the east. 1) The phrase ‘and from the Son’ was not used in the original creed therefore was anti-canonical. 2) The second concern was that filioque clause has the possibility of dividing the procession of the Spirit from two separate origins, the Father, AND the Son. The first point has some validity to it if you are looking at a historical perspective, but often the 381 Constantinople Creed is used as a confession of faith not only 325 Nicene Creed. Creeds although historical are not Scripture and can be changed. The second seeks to separate the procession into two origins, however because the Son is eternally begotten of the Father he always acts in communion with him, therefore there are not two origins of procession.
Just as the title Son of God refers to the Son’s begotenness from the Father; the Spirit, who is also called the Spirit of God refers to the Spirit’s procession from the Father and the Son. The Son is the same essence of the Father, God of God, light of light and very God of very God. The Father and the Son have the same essence, the Spirit has the same essence which proceeds from the Father and the Son. This is why the Spirit of God is called the Spirit of the Lord (Is 11:2), The Spirit of the Son (Gal 4:6) and the Spirit that proceeds from the Father (John 15:26).
Procession does not mean sending, the sending of the Spirit (eg Acts 2:4) is a historical event which happens in redemptive history. The eternal procession speaks about the “ontological Trinity” focuses on who God is, and the term “economic Trinity” focuses on what God does. The eternal procession speaks not of God’s works relating to his creation or his works of redemption; it speaks of the Triune God before creation from all eternity. The same Trinity who is (ontological) relates to his creation through works, ie what he does (economic). George Smeaton, a 19th Century Scottish Theologian explains it simply, “The three Persons have natural relation to each other, both in subsistence and action, They are one in essence and in operation.” The two are related to one another so you can see the eternal procession of the Spirit shown to us in the redemptive historical actions of being sent. However, we need to understand the difference and not blur lines.