Just One Necessary Being
A necessary being is one that must exist no matter what.
When speaking of a necessary being (to differentiate from abstracta) we mean an entity which possibly causes something (is concrete) and exists through its nature (is uncaused). Much research has been conducted on whether we should admit a necessary being into our ontology.[1] More research is needed to answer the question of how many necessary beings there are and why. This article suggests the following: necessarily, there can be just one necessary being.
Reasons for Just One Necessary Being
Imagine two necessary beings. For these being to not be the self-same reality, there must be some difference between them; some additional feature, as it were, atop their necessary nature which they have in common. However, if the difference is contingent, then the being is composite and requires a cause, contradicting its necessary nature. Alternatively, if the differences are necessary to each, then each lacks some essential feature that some other thing has on account of having a necessary nature, and so is not necessary and we encounter another contradiction. From this consideration it seems we may be constrained in the number of necessary realities – if there are any truly necessary realities at all – being just one.
A similar conclusion can be reached from the neo-Platonic tradition, which maintains that nothing composite exists through itself (which a necessary being must) since every composite entity exists through its parts.[2] So, whatever exists of metaphysical necessity must be distinctively simple or incomposite – something that has no parts, physical or metaphysical.[3] If correct, we can ask if there could be more than one simple being. However, thinking through this returns the same result as before: Imagine two simple beings. For these simple beings to not be the self-same reality, there must be some difference between them. But whatever that differentiating feature is, it would be something in addition to the simple reality (namely, a part), which reintroduces compositeness and contingency. So, if a necessary being must be a simple being, and if a simple being cannot be multiplied, then neither can a necessary being be. Hence, there can be just one.
Perhaps someone is skeptical of the notion that every composite thing requires a cause, is contingent. Nevertheless, Thomas Aquinas maintains at least that whatever a necessary being is, it cannot be metaphysically composite in the sense of having an essence (or nature) that is really distinct from its existence.[4] For Aquinas, if something’s essence is really distinct (even if inseparable for as long as it exists) from its existence, that being is contingent.[5] It could lose its existence, as we often experience. Thus, for Aquinas, if there is a necessary being, its essence must be identical to its existence.
From there, Aquinas claims there could be just one such entity, for reasons like before.[6] Namely, to have multiple instances of “that which just is its existence” requires some feature different from “that which just is its existence.” But this introduces contingency, since if something is really different or distinct from “that which just is its existence” then that something must receive existence from another. As well, if the essence of some entity Y is identical with its existence, it must be unique, since there could be nothing else that shared Y’s essence and was identical to Y’s existence without being identical to Y. So, on Aquinas’s essence-existence metaphysics there could only be one necessary being, as well.[7]
To come at this from another (more metaphysically neutral) angle, let’s say this. The necessary reality must be essentially (that is, in virtue of its nature) active. If it wasn’t, then it would need to be activated (caused), which contradicts its necessary nature. As well, it if weren’t active through itself, then something else would be making it active, which contradicts its necessary nature. Either way, such an entity could not be multiplied since it would not be susceptible to differentiating features. Why? Notice: anything really different from that which is actual through itself must be either 1) not actual (in need of a cause) or 2) not actual through itself (being caused), either of which results in our positing contingency into the nature of this necessary reality = contradictory. Even more, there can be no potential (something that could be but is not already) part in this necessary reality, because that potential itself would have to be activated (caused) and then we are once again talking about a contingent-necessary reality = contradictory.
So far, it seems however we slice it, we cannot make sense of multiple instances of any truly necessary being. By truly necessary I mean something that is active entirely through itself. Ostensibly, one might hold to a sort of lesser “necessary” being that is always existing because of (say) the causal activity of the more fundamental necessary being, but such hypothetically lesser necessary beings are not necessary in the sense we’re investigating. Though they may always be there, they are still necessary through (dependent upon) another, and therefore not strictly necessary in their existence.
I finish by listing some “suggestive” (indicative but not decisive) reasons philosophers have thought that if there is a truly necessary being, there is just one.
First, is basic parsimony. Unless there is reason to believe there is (or must be) more than one necessary being, why posit more? One may take parsimony considerations as motivation to adopt whatever paradigm posits some reality capable of satisfying the criteria of a necessary being and is metaphysically robust enough to account for contingency (since, presumably, the reason anybody wants to include a necessary being in the first place is to provide a causal explanation of contingent beings). There seem to be several options available, the exposition of which extends beyond the scope of this article.
Second, Robert Koons reminds us that “the unity of space is constituted by an infinite number of precisely coordinated relational facts, … if there were no causal explanation of these facts, we would have an infinite number of brute, unexplained coincidences.”[8] Koons argues that an explanation of the unity of space-time coincidences must itself be outside space: making it a non-spatial and immaterial agent. It so, it would then seem counterproductive to posit more than one such entity, since we would need to then explain their underlying unity or togetherness. Better to just have one external unifier for all space-time coincidences.
Finally, the traditional Platonic intuition that The Many are always derivative of The One. For example, if things have some one positive attribute in common (for example, existence), it is certainly counterintuitive to say they share this common feature in virtue of underlying diversity. As Norris Clarke argues, “For similarity is a form of unity and cannot be adequately grounded in diversity. It is not because they are many and diverse that they share the same real property. Hence the only adequate sufficient reason for this common sharing, this real similarity among them, must be some one unitary source from whence this common perfection ultimately derives and is communicated to all participants.”[9] Following Clarke, this suggests (but does not prove) a single, unified source from which the participants in existence derive their actuality.
See Also:
[1] For example, Pruss, Alexander R., and Joshua Rasmussen. Necessary Existence. Oxford University Press, 2018.
[2] Traditional metaphysicians like Thomas Aquinas have said a necessary being must also be a purely actual being, without potency. If so, this gives another reason to think a necessary being must be absolutely simple, since whatever is composite possesses potency in its being insofar as parts ordered toward a unity must be related as potency to act, and is therefore not existent through itself. Thomas Aquinas, Summa Theologica, I, q.3, a.7, at The Aquinas Institute, www.aquinas.cc
[3] For an exposition, see Gerson, Lloyd P. Plotinus. Routledge, 1998. Chapter 1.
[4] Thomas Aquinas, De ente et essentia, at The Aquinas Institute, www.aquinas.cc.
[5] Of course, someone may object that it makes no sense to say God is identical to his existence, assuming 1) existence is a property that everything exemplifies and 2) exemplifies picks out an irreflexive and asymmetrical relation between terms. But there are good reasons to reject this analysis of existence. As philosophers like William Valicella have argued, existence is not one of an individual’s properties, but rather than in virtue of which it has any properties in the first place. Or as he puts it, “It is more like the unity or cohesion of an individuals’ properties.” 2002, Vallicella, William F. A Paradigm Theory of Existence: Onto-Theology Vindicated. Dordrecht: Kluwer Academic Publishers, 2002. Chapter 6.
[6] In De Ente, Aquinas is thinking hypothetically, at first: if something existed in virtue of what it is (whose essence just is its existence) then that something must be utterly unique. Only later does Aquinas argue that just such an entity exists. Thomas Aquinas, De ente et essentia.
[7] Elmar Kremer makes a similar argument in developing the work of Barry Biller, “Suppose m and n are two individual instances of subsistent existence. That means that each one is the same as its existence. But if the two are distinct, then the existence of m is distinct from the existence of n. Hence the existence of each one is individuated by that of which it is the existence: the existence of m is individuated by m, and the existence of n is individuated by n. Hence each one is distinct from its existence. But each one is by hypothesis the same as its existence. Therefore, there can only be one subsistent existence.” Kremer, Elmar J. Analysis of Existing: Barry Miller's Approach to God, Bloomsbury, New York, 2015. pg. 75.
[8] Novotny, Daniel, and Novák Lukáš. Neo-Aristotelian Perspectives in Metaphysics. Routledge, Taylor & Francis Group, 2016. Pg. 263.
[9] W. Norris Clarke. The One and The Many: A Contemporary Thomistic Metaphysics. South Bend, IN: University of Notre Dame, 2001. Pg. 223.