Category Archives: Naturalism

A Modal Argument Against Naturalism from Transcendentals

For any argument against naturalism, we are going to have to specify the sort of naturalism we are discussing.  Here, my target is a rather broad notion of metaphysical naturalism.  Let’s define the notion in the following way: naturalism is the thesis that reality is exhausted by the natural.[1]  This is, admittedly not an informative definition (and somewhat circular), but it will do the job of being relatively broad for this argument, but not so vacuous as to be uninteresting.  Many contemporary naturalists would assent to the definition, and I, being Catholic, believe that naturalism, so defined, is false.

P1. Naturalism is true just in case “natural” is greater than and includes the combined extensions of terms that name each and every one of the categories into which being may be divided.[2]

P2. “Natural” is greater than and includes the combined extensions of terms that name each and every one of the categories into which being may be divided just in case “natural” is a transcendental that is convertible with “being”.

P3. All terms that are transcendental that are convertible with “being” are necessarily transcendentals that are convertible with “being”.

P4. If naturalism is true, naturalism is contingently true.

P5. If naturalism is contingently true, it is false that “natural” is necessarily a transcendental that is convertible with being.

C1. Therefore, naturalism is false.

The argument is a reductio, as the premises lead to an obvious contradiction if one assumes naturalism is true (i.e. “natural” is necessarily a transcendental that is convertible with “being” and it is false that “natural” is necessarily a transcendental that is convertible with “being”). Given the definition of “transcendental” and the plausibility of P3-P5, naturalism cannot be the case.

There are a few ways the naturalist may object (and why I think they are inadequate objections):

Objection 1: “Natural” is not a transcendental.

Reply to 1: If “natural” is not a transcendental, as defined extensionally, then it is not exhaustive of reality.  Let’s say that reality is composed of everything, all beings.  If “natural” doesn’t exhaust all beings, then there are beings that are not natural.  That, to me, is sufficient to falsify metaphysical naturalism.  So this is not a very good move to make, though it may be a knee-jerk move to make in response to the argument.

Objection 2: There are no transcendentals.  The idea that res, unum, aliquid, bonum, et verum or any other supposed transcendental like “beauty” is convertible with being is a quaint notion from an outmoded era of philosophy and theology when people drank in far too many Hellenistic notions.

Reply to 2: Fine, you dislike older ideas.  But the extensional definition of transcendentals are still on the table and there is no reason to think that we cannot categorize being, or devise a notion of a term that is universal.  After all, as I suggested in response to the first objection, to say that “natural” exhaust reality is to say something about the universality of “natural” and that its extension would be as broad as “being” or “reality”.  So, it sounds odd to object to there being transcendental terms when naturalism, so defined, depends on it.  Ah, but “naturalism” could be defined in other ways.  That’s true, but those sorts of “naturalisms” are not the target of this argument.  Moreover, I am not too sure that I am opposed to a form of metaphysical naturalism that is too timid to claim that “natural” exhausts “being”.

Objection 3: P3 is false.  There is no reason to think that if some term is convertible with “being”, then it is necessarily so.  It might be contingently convertible with being, especially if “transcendental” is only being defined extensionally.  That is, the transcendentals could merely happen to be convertible with “being”.

Reply to 3: It would seem, then, that we have two sorts of transcendentals: contingent transcendentals that happen to be convertible with “being” and necessary transcendentals that are necessarily convertible with “being”.  So, for instance, if God were actually to exist, there would be a sense in which res, unum, aliquid, bonum, et verum could be applied to God.  But, presumably, if God were to exist, “natural” could not apply to Him.  In other words, were there super-natural beings, “natural” would have a smaller extension than “being” and “natural” would cease to be a transcendental.  Yet, the other named transcendentals are not like this.  No matter what possibilia comes to be, the transcendentals would remain what they are.  It’s just that the actualization of the possibilia means that the actuality is res, unum, aliquid, bonum, et verum.  It seems, then, that the naturalist would be committed to the thesis that “natural” is convertible with “actual”, i.e. everything is actual if and only if it is natural.  But “actuality” is not a transcendental.  Rather, one can divide the various categories of being into act and potency.  In other words, actuality has a smaller extension than any given category and, a fortiori the combined extensions of all the categories of being.  Now the naturalist might quibble and say that any potential or possibility of the non-natural, or supernatural, is itself natural.  But this is not to address the question of whether “natural” is extensive with all potentials and possibilities, but just the actualities in which those potentials and possibilities obtain.

Another issue is that it is rather question-begging to demand that “natural” is one instance of a “contingent transcendental” convertible with being given what actually happens to exist.  Is there another such transcendental? Why are all the other transcendentals necessary and remain transcendentals no matter what happens to be in the world.

Objection 4: P4 is false.  Metaphysical worldviews, if true, are necessarily true.  Thus, if metaphysical naturalism is true, then it is somehow necessarily true.

Reply to 4: This is a rather strong position to take.  For it not only posits that supernatural entities, like souls, and gods, do not exist.  It posits that they cannot exist for metaphysical or broadly logical reasons.  It is not clear to me why this must be the case, and there seems to be good reason to think this is false.  1) Even if it is not supposed that the Anselmian God is metaphysically possible (from which, some would argue, His existence could be demonstrated), a less than maximally great or perfect divinity is plausibly metaphysically possible.  That is, a being that would sufficiently falsify naturalism, even if it is not morally perfect, omniscient, or omnipotent, could exist.  What’s more, if metaphysical naturalism is metaphysically necessary, then it would satisfy the Leibnizian question “why is there something rather than nothing” in much the way classical theists think God satisfies this question.  The classical theist says that God is metaphysically necessary, so not anything existing is impossible.  But the metaphysical naturalist doesn’t seem to make the same move.  Faced with the radical contingency of reality, the metaphysical naturalist usually doesn’t say that since metaphysical naturalism is metaphysical necessary, there must be at least one natural thing in existence.  If nothing were in existence, then nothing natural would exist.  Now a particularly impish naturalist might suggest that, were there nothing in existence, metaphysical naturalism would be true.  That is, one natural configuration of the world is “there not being anything”.  But if there were nothing, it wouldn’t be the case that “natural” exhausts reality.  “Natural” would not be predicated at all.  It would no more “exhaust” reality than “supernatural”.  So there not being anything is not compatible with metaphysical naturalism being true.  So if metaphysical naturalism is necessary, nothing is intrinsically impossible.  Yet, we have no reason to think that if naturalism is true, some natural thing or other must exist.

Objection 5: Okay, metaphysical naturalism is only contingently true, but “natural” is necessarily a transcendental convertible with being anyways.  In other words, P5 is false.

Reply to 5: Well, if there is no possible world where “natural” fails to exhaust “being”, then metaphysical naturalism would be true in every possible world.  Metaphysical naturalism cannot be contingent while it be necessary the everything is natural.  That just is to claim that metaphysical naturalism is true in every possible world (a strong claim to make).

In Sum: If I were a naturalist, I think I would try to argue that some transcendentals are contingent. I don’t think the argument would be very convincing, for the reasons I mentioned.  After that, I think I would want to argue that metaphysical naturalism is necessary.  Remember, it is not enough to simply say that metaphysical naturalism could be necessary. If all of the other premises of my argument are correct, and one wants to maintain metaphysical naturalism as true, one would have to admit that the only way it could be true is if it is metaphysically necessary.  However, I don’t see any good reason to think metaphysical naturalism is metaphysically necessary for the reasons I’ve outlined above.  So, it seems to me that, since “natural” is not a transcendental of “being”, metaphysical naturalism is false.

[1] Papineau, David, “Naturalism”, The Stanford Encyclopedia of Philosophy (Spring 2009 Edition), Edward N. Zalta (ed.), URL = <>.

[2] This is based on an extensional definition of transcendentals offered by Jorge J.E. Gracia. See Jorge J.E. Gracia, 1992, “The Transcendentals in the Middle Ages: An Introduction,” Topoi 11(2): 113–120. Also Wouter Goris and Jan Aertsen, “Medieval Theories of Transcendentals”, The Stanford Encyclopedia of Philosophy (Summer 2013 Edition), Edward N. Zalta (ed.), URL = <>


An Argument Against Naturalism from the Desire to Know








1.  All humans actually desire knowledge essentially. [Premise]




Now there are a few ways the naturalist could object:








An Argument from the Regularity of Nature to the Falsity of Metaphysical Naturalism

I find the following argument compelling:

P1. If it is both the case that something has an explanation and that explanation is natural, then it has an explanation that depends on the actuality of the regularity of nature.
P2. If something is contingent, it is not the case that it has an explanation that depends upon the actuality of itself.
P3. All things that are actual are possible.
P4. All things that are possible, and not necessary, are contingent.
P5. All things that are contingent have an explanation.
P6. The regularity of nature is actual.
P7. The regularity of nature is not necessary.
P8. If something has an explanation and it is not the case that the explanation is natural, then metaphysical naturalism is false.
C1. The regularity of nature is possible (from P3 and P6).
C2. The regularity of nature is contingent (from P4, P7, and C1).
C3. The regularity of nature has explanation (from P5 and C2).
C4. It is not the case that the regularity of nature has an explanation that depends upon the actuality of itself (from P2 and C2).
C5. It is not both the case that the regularity of nature has an explanation and that explanation is natural (from P1 and C4).
C6. It is not the case that the explanation of the regularity of nature is natural (from C3 and C5).
C7. Therefore, metaphysical naturalism is false (from P8, C3, and C6).

An Argument Against Naturalism from Abstract Objects

Some naturalists, like Quine, feel compelled to admit abstract objects, like numbers, sets, and propositions, into their ontology. But I’ve always had the sense that abstract objects are incompatible with naturalism. Here I will lay out some premises about abstract objects and naturalism that appear fairly intuitive to me. I will then represent those premises in logical notation, and demonstrate that they do, indeed, serve as a defeater for naturalism.

1. If a thing1 is natural then it is possibly not the case that there exists a thing2 where thing2 is natural and identical to thing1.

In other words, if a think is natural, then it possibly doesn’t exist.

2. There exists some proposition such that necessarily that proposition is true.

For example, the mathematical proposition ‘2 + 3 = 5’ is necessarily true and cannot be false.

3. For all propositions, necessarily, if a proposition is true, then there exists some thing1 such that thing1 is abstract and thing1 is identical to that proposition.

This is just to say that it is necessary that if a proposition is true, then it is an existing abstract object. After all, it would seem odd to predicate a truth-value to a proposition, but deny that said proposition doesn’t exist.

4. If there exists a proposition that is necessarily true, and everything is natural, then for all proposition, necessarily, if there exists a thing1 that is an abstract object identical to that proposition, then there exists a natural thing2 identical to that proposition.

I defend this premise on the grounds that, if a proposition is natural, then in every world where it obtains, it obtains as a natural proposition. That is, if ‘natural’ is predicated of a proposition, it is essentially predicated of it, which is to say that in every world where that proposition exists, it exists as a natural object.

From these four premise, we can conclude that naturalism, which I take to be the claim that everything is natural, is false.

The deduction is as follows:

Nx – x is natural
Tp – p is true
Ax – x is an abstract object

1. (∀x){Nx ⊃ ♢~(∃y)[Ny & (y=x)]} (premise)
2. (∃p)☐Tp (premise)
3. (∀p)☐[(Tp ⊃ (∃x)(Ax & (x=p))] (premise)
4. (∃p)(☐Tp & (∀x)Nx) ⊃ (∀p)☐{(∃x)[Ax & (x=p)] ⊃ (∃y)[Ny & (y=p)]} (premise)
6. ☐Tu (2 EI)
7. ☐[(Tu ⊃ (∃x)(Ax & (x=u))] (3 UI)
8. ☐(∃x)(Ax & (x=u) (6,7 MMP)
9. ☐{(∃x)[Ax & (x=u)] ⊃ (∃y)[Ny & (y=u)]} (5, UI)
10. ☐(∃y)[Ny & (y=u)] (8,9 MMP)
11. (∃y)[Ny & (y=u)] (10 NE)
12. Nv & (v=u) (11 EI)
13. Nv ⊃ ♢~(∃y)[Ny & (y=v)] (1 UI)
14. Nv (12 Simp)
15. ♢~(∃y)[Ny & (y=v)] (13,14 MP)
16. (v=u) (12 Simp)
17. ♢~(∃y)[Ny & (y=u)] (15,16 ID)
18. ~☐(∃y)[Ny & (y=u)] (17 MN)
19. ☐(∃y)[Ny & (y=u)] & ~☐(∃y)[Ny & (y=u)] (10,18 Conj)
20. ~(∀p)☐{(∃x)[Ax & (x=p)] ⊃ (∃y)[Ny & (y=p)]} (IP 5-19)
21. ~(∃p)(☐Tp & (∀x)Nx) (4,20 MT)
22. (∀p)~(☐Tp & (∀x)Nx) (21, QN)
23. ☐Tu (2 EI)
24. ~(☐Tu & (∀x)Nx) (22 UI)
25. ~☐Tu ∨ ~(∀x)Nx (24 DeM)
26. ~~☐Tu (23 DN)
27. ~(∀x)Nx (25,26 DS)
28. (∃x)~Nx (27 QN)

Line 28 is our conclusion, namely that something exists that is not natural. I take this to be incompatible with naturalism. Therefore, I take the existence of abstract objects, like propositions, to be a defeater for naturalism. I suspect that the naturalist will take issue with one or more of the premises, but at a cost. Likely (4) will require the most defending. Again, (4) says that, given naturalism and the existence of necessary truths, it is necessarily the case that if a proposition exists as an abstract object, it will exist as a natural object. If one denies this, then it would seem possible that an abstract object be natural and possibly not natural. But then in what way is it the same sort of thing? It seems odd to me that a proposition is a natural thing in this world, but a non-natural thing in other possible worlds. For it seems to me that the property of being natural is an essential property. If something is natural, it is necessary that it is natural. Thus, if naturalism is true, then all abstract objects are natural and essentially natural. But our argument shows, by indirect proof, that it is possible for there to exist an abstract object that is not natural. Giving up on (4) entails that ‘natural’ is non-essential to some things, and I find that to be implausible.

(My thanks to Skepticism First on Twitter, who dialogued with me on this argument and pushed me in some new directions)

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