A necessary and sufficient condition for being a universalist is that you maintain UNIVERSAL. According to UNIVERSAL, every being that could have salvific union with God will have salvific union with God. However, universalists differ with respect to (i) the scope, (ii) modal register, and (iii) metaphysical account of UNIVERSAL. Thus, as I will illustrate below, depending on your views regarding (i)-(iii), your answer to the question, “Who will have salvific union with God?,” will change. There is also a question about (iv) the semantics of ‘will have,’ but we will not discuss that here.
(i) Scope
We can ask, what is the scope of the quantifier present in UNIVERSAL? is it restricted or unrestricted? Call a quantifier ‘unrestricted’ if it ranges over absolutely all objects. In ordinary discourse, our quantifiers are often restricted to some contextually salient domain. For instance, suppose that someone asserts ‘Everyone came to the party’. Ordinarily, we would not take this assertion to imply that everyone in the entire world came to the party. We would interpret the quantifier as being restricted to some contextually relevant class of people, i.e. everyone who was invited to the party. Now, are our quantifiers always restricted in this way? Prima facie, the answer appears to be ‘no’. There are various contexts where it would be natural to take the quantifiers to be unrestricted. For instance, when a philosopher asserts ‘Everything is self-identical’ or ‘There are no abstract objects’, we typically take the quantifiers to range over all objects whatsoever. So, is UNIVERSAL restricted to some contextually salient domain? or is it unrestricted in scope? If it is restricted, what are we ranging over? According to some universalists, we are only ranging over human persons. According to others, we are ranging over all of the creation.
(ii) Modal Register
We can ask, is UNIVERSAL necessarily true or contingently true? If we were to suppose that UNIVERSAL were necessarily true, then we get NEC-UNIVERSAL. According to NEC-UNIVERSAL, necessarily every being that could have salvific union with God will have salvific union with God. To be more precise, we have: □(∀x) Sx → Hx. Let ‘S’ be the property of being the kind of being that could have salvific union with God, and let ‘H’ be the property of eventually having salvific union with God. According to this view, there is no possible world where some being that could have salvific union with God does not have salvific union with God. Thus, depending on your view regarding the scope of UNIVERSAL, it could necessarily be the case all beings capable of being in salvific union with God are in salvific union with God. If, however, we were to suppose that UNIVERSAL were only contingently true, then we get POS-UNIVERSAL. According to POS-UNIVERSAL, possibly every being that could have salvific union with God will have salvific union with God. To be more precise, we have: ◊(∀x) Sx → Hx. According to this view, there are possible worlds where all beings that could have salvific union with God do not have salvific union with God, but there are some possible words where all beings that could have salvific union with God are in salvific union with God. Thus, depending on your view regarding the scope of UNIVERSAL, it is only contingently the case that all beings capable of being in salvific union with God are in salvific union with God.
(iii) Metaphysical Accounts
The central metaphysical question any universalist thesis must be supplemented with is, in virtue of what does salvific union with God obtain? Answers to this question are metaphysical accounts of UNIVERSAL—coherent stories in which salvific union with God is explained in universalist-friendly terms. For the sake of brevity, I will not outline every metaphysical account of UNIVERSAL, but this is just one particularly interesting view which has odd implications regarding the salvific state of persons. This view is universalist since it affirms UNIVERSAL. According to quasi-universalism, for every person P who enjoys union with God at granted time t, there is another person P+ who will not enjoy union until t+1. So no matter how many souls get saved, there is some soul that does not get saved. It follows that, no matter what the time, some soul is not saved. Thus, supposing that for every person P who enjoys union with God at granted time t, there is another person P+ who will not enjoy union until t+1, then there will be no end to the number of people and there may be persons who never realize their salvific union with God. For more accounts of UNIVERSAL, I would recommend reading the work of Origen, Gregory of Nyssa, Eric Reitan, John Kronen, and Thomas Talbott.
Another issue about scope that might be worth thinking about: are only actual individuals relevant, or are possible and perhaps even impossible individuals relevant too?
I kept modal realists in mind and did not characterize UNIVERSAL as the thesis that every actual being that could have salvific union with God, will have salvific union with God. For modal realists, all actual human beings and all of their counterparts and duplicates—alongside any other beings satisfying the formula ‘(x)Sx)—go to (counterpart) heaven.
So, given modal realism, you’re going to have a lot of concrete, non-actual beings going to (counterpart) heaven, along with all the actual ones.
A universalist could think that only all actual individuals go to heaven, maybe especially if they are a meinongian or a possibilist who is not a modal realist.
That seems right. A Meinongian or possibilist universalist would have to offer a pretty comprehensive view in which Meinongian individuals or merely possible individuals are the kinds of beings that could have salvific union with God. Otherwise, the inclusion of these individuals would appear to be ad hoc.
Hello, pilgrim from Twitter here. I have three thoughts.
(i) seems to be a bit too general, if we are logically precise. Consider the formula ∀x ∈ S.H(x), where H has your definition and S is an arbitrary set. Formally, this is the sentence ∀x.(x ∈ S → H(x)), which shows why your suggestion is too general. You can just adjust the definition of S however you want, and get eschatologies which are not universalist at all! Calvinists could affirm this formula, as well as even those who believe that no one will be saved, in which case S would be the empty set.
I am not concerned about the logical coherence of UNIVERSAL. In my opinion, it is the only possible option, given that a good God exists. What bothers me are certain confessional epistemic issues with accepting Universalism. For example, it is a fact of history that universalism was always the minority position. Is there any plausibly correct Christian denomination which can incorporate this fact into its own ecclesiology while remaining coherent? Coming from a Catholic background, I can assure you that the above fact has very problematic implications for Catholic ecclesiology, for example.
Thirdly, I would like to warn you about quantified modal logic. There is no agreed-upon semantics of this system, so the two quantified modal formulas you write down have no standard meaning. In fact, there are multiple cogent ways to develop a semantics of quantified modal logic, unlike basic propositional modal logic, and that is why it is not as widely used. For more information, see section 15 in the SEP entry on modal logic:
https://plato.stanford.edu/entries/logic-modal/
I wish you a blessed 2023!