The objection
God is triune. The Son is God. The Son would therefore have to be triune. Trinitarian doctrine denies the conclusion and thus seems to violate a simple logical inference.
1. The inference works only with an unchanged referent
If “God” were throughout the proper name of a fourth person and “the Son is God” an identification with this person, the inference would be compelling. But this is precisely not what Trinitarian doctrine teaches. Alongside Father, Son and Spirit there is no further divine bearer with whom each person would have to be identified.
Mooney's objection reveals an important task of clarification: We must explain what statement “is God” makes in each case rather than silently letting the word shift between different meanings.[1]
2. Triunity designates no fourth essential attribute of an individual person
Omniscience designates a divine perfection. “Triune,” by contrast, designates that the one divine being subsists in Father, Son and Spirit. It does not say that each person again has three persons within themselves. Otherwise the personal order is introduced anew in each person, and the doctrine would no longer be the asserted number three.
“The Son is God” in this context means: The Son possesses the undivided divine reality, not merely a share of it. It does not mean: The Son is Father, Son and Spirit simultaneously. The distinction between a statement of being and personal reference is also expressly a topic in Thomas.[3]
3. Language must nevertheless not become an evasion
Pointing to different kinds of statement does not settle every metaphysical question. Anyone understanding “divine” merely like “human,” as a jointly possessed kind, would still have three divine instances. The numerical unity of deity therefore belongs indispensably to the explanation.
Czepielik shows how the so-called new problem connects with existing solutions to the original Trinity problem. The conceptual requirements do not disappear; but they do not arise only through the word “triune.”[2]
4. John himself supplies the necessary distinction
The Logos is with God and is God. The evangelist thereby joins personal relationship and full deity without equating the Logos with the Father. The later confession makes this connection explicit.
The inference “therefore the Son is three persons” arises only when the deity statement is made into a complete equation of the person with the entire personal order. This additional assumption requires justification. It must not first be read into the doctrine and then presented as its contradiction.
Biblical texts in context
Sources and further study
- Justin Mooney, A New Logical Problem for the Doctrine of the TrinityReligious Studies 54/1 (2018), pp. 1–13; formulation of the Triunity Problem.
- Agnieszka Czepielik, No new problem for the Trinity: A reply to MooneyReligious Studies 62/1 (2026), pp. 197–213; connection to the original identity problem.
- Thomas Aquinas, Summa theologiaeI, q. 39, a. 4: how the designation God can stand for a person in statements.