The objection
If the Father is source of the Son and Spirit, he possesses something they lack. Only he then seems to be the highest God; Son and Spirit would be derived and subordinate divine beings.
1. Distinctiveness is not imperfection
The Father is not Son, and the Son is not Father. It does not follow that either lacks a divine perfection. Being Father is no higher quantity of deity. It designates a personal relationship. If it were a perfection required for full deity, the Son indeed could not be fully God. But precisely this premise is false.
Conversely, the Father lacks no divine perfection because he is not Son. The relationships differ; being, power and glory are not distributed by ranks.
2. “Source” must not silently mean “Creator”
In classical language about the Father's monarchy, source designates the order of personal relationships. Thomas explains in I, q. 33, a. 1 that this asserts neither temporal priority nor an inferior nature of the one from the Father. He precisely avoids a meaning of cause suggesting separate substances and creaturely dependence.[1]
A chain “highest God—lower god—still lower being” would not interpret the Trinity but replace it with graded deities. Anyone deriving such gradation from the word source must first show that the concept of origin used actually contains this meaning.
3. John connects order and equal divine honor
John 5 names the Father as the one who sends and gives the Son authority to judge. The same context says that the Son gives life to whom he wills and that all are to honor him as they honor the Father (5,21–23). The order of mission does not abolish equal divine honor.
John 16,14–15 describes the Spirit as the one who glorifies Christ and takes from what is his. Jesus adds that everything the Father has is his. The missions disclose the persons' fellowship. They do not permit turning every direction of giving into a rank of inferior deity.
4. No person possesses a greater deity
Thomas grounds the persons' equality in the fact that the one divine being permits no more and less. A greater deity of the Father and a smaller one of the Son would precisely not be the same undivided deity.[2]
Christian traditions do not explain relationships of origin, and particularly the Spirit's procession, identically in every respect. These differences must be distinguished from the shared boundary: Son and Spirit are neither creatures nor lesser gods. “Monarchy” is a Trinitarian statement only if it preserves this boundary. It designates no rule of one divine individual over two inferior fellow gods.
Biblical texts in context
Sources and further study
- Thomas Aquinas, Summa theologiaeI, q. 33, a. 1: origin without temporal priority or diminishment of being.
- Thomas Aquinas, Summa theologiaeI, q. 42, a. 1–2: equal deity, power and eternity.