John Calvin gained quite a bit of attention in regards to his trinitarianism (or lack thereof) during his lifetime due to his innovative assertion that the person of the Son is “autotheos”. “Autotheos” is a Greek term that means ‘God of Himself’, and indicates self-causality. Historically, this term had been applied to the person of the Father exclusively, and denied to the other persons of the Trinity, on the basis of Their being not ‘of themselves’ or ‘self-originated’ rather ‘of the Father’, as He is the cause of Their existence, of the Son by eternal generation and of the Holy Spirit by eternal procession.
Being “autotheos” has sometimes historically been distinguished from the attribute of aseity, which refers to self-existence, on the basis that while the scriptures teach that the Father alone is without Cause and is the Cause of His Son and Spirit, the Son and Spirit, in having the same divine nature as the Father, have self-sustained existence, just as He does.
That much at least can be shown from scripture, as it teaches on the one hand that the existence of all creation is perpetually upheld and sustained through the Son: “Who being the brightness of his glory, and the express image of his person, and upholding all things by the word of his power, when he had by himself purged our sins, sat down on the right hand of the Majesty on high:” (Hebrews 1:3 KJV) while the Son, on the other hand, does not have His existence upheld by the Father, but rather has “life in Himself” just as the Father does: “For as the Father hath life in himself; so hath he given to the Son to have life in himself;” (John 5:26 KJV).
So the Son, like the Father, has self-sustained existence; at the same time, the same verse from which we see this point of doctrine proved also proves that the Son does not have this self-sustained existence original to Himself, but from the Father. He has ‘life in Himself’, but not ‘life of Himself’, but rather of the Father in His eternal generation.
Along these same lines of thinking then, from the patristic era onward, theologians have acknowledged both the Son and Father to each have “life in Himself”, and yet have acknowledged that he Son has life “of the Father”- both of which are biblical assertions. They have also historically gone a step beyond this by saying that while the Son has life not ‘of Himself’, but rather ‘of the Father’ that the Father does have life ‘of Himself’. He, they have asserted, is God of Himself, ‘autotheos’. And since the Son is from Him as His cause, it is absurd to say that the Son is autotheos.
While I would agree that it is wrong to call the Son autotheos, I believe it is actually a mistake to ascribe this to the Father either. First lets briefly examine the Son: He is begotten of the Father, and has His being and essence from the Father. He is not self-caused, but caused by the Father. Therefore, it is false and clearly contrary to scripture to assert that the Son is autotheos, as it ultimately amounts to a denial of eternal generation and tries make the Son equal to the Father not only in respect to His divine nature, but also His ‘personal properties’, the incommunicable properties that belong to the Father alone, and thus effectively makes the Son out to be a second God.
While I stand in agreement with nearly all Christian thought on this matter prior to Calvin in respect to the Son being ‘autotheos’, I would stand at odds with the same in respect to my denial that the Father is autotheos. My reason: I believe there is a significant conceptual difference between being ‘uncaused’ and being ‘self-caused’, and that these two ideas have usually been blended together and treated as equivalent in Christian theology, at least much of what I have seen.
There is however, and significant difference to be drawn between these two ideas. To be uncaused, involves having no origin, source, beginning, or cause whatsoever. It is to be unbegotten, uncreated, unproceeding, and otherwise entirely unoriginate. There is much attestation to the scriptural truth that the person of the Father is all these things in the early church fathers. And scripture attests to same: see Why There is Only One God: One Supreme Cause for more on this.
However, where does scripture ever speak of God as self-caused? There is no place I am aware of. The closest thing to that would be the assertion that all things are from Him in 1 Corinthians 8:6; yet by the same logic that would allow us to say that although all things are “through” the Son, the Son Himself is excluded, we can understand that this is not meant in such an absolute way as to indicate self-causality. Rather, God simply “is” without cause, while He Himself is the cause of all else, even of His Son and Holy Spirit eternally, through Whom He created all things.
There is a value in distinguishing between self-causality and uncausality, however, not just for sake of understanding this distinction itself, and that the Father is uncaused, not self-caused, but also for sake of its implications to the rest of theology, which I would suggest are actually quite vast. This is because self-causality is a positive property, while uncausality is a negative property. When we say God is uncaused, we say something about what He is not. But when someone says God is self-caused, they are saying something about what he is.
Why is this difference important? Because we understand from scripture that God is simple in His nature: He is what He is. His attributes aren’t just something external to Himself which he possesses- they are what He is. God is the very definition of all He is. Thus we say, with scripture, not merely that God is loving, but that God is love, because He is what He is, and so is in His nature the very definition of all His attributes.
These attributes, however, which are in view when we speak of simplicity do not include relative attributes such as being Father, nor being uncaused. This is because these things are not the “what” of Who God is. In a similar way, Adam was unbegotten, yet He is the same thing, that is, has the same nature, as His Son Seth who was born of Him. It is not proper to Adam’s essence to be unbegotten, nor to be a father, or else we would say that his human nature was altered when he had children. So we view these relative relational properties among the persons of the Trinity, such as being unbegotten and uncaused in the case of the Father, and begotten in the case of the Son, as relative personal properties which must be distinguished from what God and His Son are in Their nature. For this reason, we can say that although the Son is not unbegotten like the Father, He is still God in that He has the same divine nature as the Father. Since being uncausality is not an essential attribute, the Son lacking this property does not in any was cause a difference in the nature of the Son from that of the Father, but rather the divinity of the Son is exactly identical to that of the Father.
But self-causality, on the other hand, as a positive attribute describing what God is, would indeed be an essential attribute, in light of the simplicity of the divine nature. God being what He is, He would be self-existence. The problem: the Son and Holy Spirit do not possess the attribute of self-causality, as They are caused by the Father. This would then logically lead to the Son and Spirit not having the same divine nature as the Father. They would ultimately be excluded from the Father’s divinity.
The Son and Holy Spirit however, as we have noted, have the same divine nature as the Father, and with that, all the same essential attributes as the Father. Therefore, either the Son and Spirit must also be self-caused with the Father, or else the Father is not self-caused. If the Son and Spirit were self-caused, then They are not truly either Son nor Spirit, and They would constitute two additional Gods alongside the Father, as there would then be three equal ultimate causes. This obviously is not the case. It is proven then, that the Father is not self-caused.
The difference then between the Father being uncaused or self-caused, when each is carried out consistently to its logical implications, is the difference between homoousian trinitarianism and arianism.