# De Ente and the Falsity of Naturalism

Thomas Aquinas writes:

…[E]verything that is in a genus has a quiddity beyond its existence, since the quiddity or nature of the genus or species is not in the order of nature distinguished in the things of which it is the genus or species, but the existence is diverse in diverse things (De Ente V.).

Given some basic modal theorems and axioms, and the above considerations, the following argument occurred to me:

P1. If naturalism is true, everything is in the genus “nature”.

P2. If everything is in the genus “nature”, then everything has a quiddity beyond its existence.

P3. Necessarily, if there is some x such that its quiddity is nothing other than its existence, then necessarily there is some x such that its quiddity is nothing other than its existence.

P4. If there is something x such that its quiddity is nothing other than its existence, then not everything has its quiddity beyond its existence.

P5. Possibly, there is some x such that its quiddity is nothing other than its existence.

C. It is not the case that naturalism is true.

Defense of P1: Naturalism just is the thesis that everything that exists is natural, and so belongs to the generic class “nature”.

Defense of P2: According to Aquinas, if the quiddity, or essence, of a thing is in a genus, then its quiddity cannot be its existence, since a genus admits of more than one instance, and whatever has its existence as its quiddity cannot admit of more than one instance.

Defense of P3: If something has its existence as its quiddity, then it has existence per se and so necessarily so. This is necessarily implied, since it is analytically true.

Defense of P4: This would be based on the notion that if a quiddity is the same as its existence, then its quiddity would not also be beyond its existence, for then the quiddity and existence could not be the same.

Defense of P5: This is just to say that it is at least metaphysically possible that something’s quiddity and facticty are the same. There does not appear to be anything impossible about such a notion, at least *prima facie*.

Formal Proof:

Let,

N ≝ Naturalism is true

Gxy ≝ x is in the genus y

Q(F,x) ≝ F is ths quiddity of x

B(F,G,x) ≝ F is beyond G for x

E! ≝ existence

n ≝ nature

Theorem of K: ☐(p → q) → (♢p → ♢q)

Theorem of S5: ♢☐p → ☐p

Axiom M: ☐p → p

1. N → (∀x)Gxn (premise)

2. (∀x)Gxn → (∀x)(∀F)[(Q(F,x) → B(F,E!,x)] (premise)

3. ☐{(∃x){[Q(E!,x)∧(∀F)~(F = E!)]→ ~Q(F,x)} → ☐(∃x){[Q(E!,x)∧(∀F)~(F = E!)]→ ~Q(F,x)]}} (premise)

4. (∃x){[Q(E!,x)∧(∀F)~(F = E!)]→ ~Q(F,x)} → ~(∀x)(∀F)[(Q(F,x) → B(F,E!,x)] (premise)

5. ♢(∃x){[Q(E!,x)∧(∀F)~(F = E!)]→ ~Q(F,x)} (premise)

6. N → (∀x)(∀F)[(Q(F,x) → B(F,E!,x)] (1,2 HS)

7. ☐{(∃x){[Q(E!,x)∧(∀F)~(F = E!)]→ ~Q(F,x)] → ☐(∃x){[Q(E!,x)∧(∀F)~(F = E!)]→ ~Q(F,x)]}} → {♢(∃x){[Q(E!,x)∧(∀F)~(F = E!)]→ ~Q(F,x)]} → ♢☐(∃x){[Q(E!,x)∧(∀F)~(F = E!)]→ ~Q(F,x)]}} (Theorem of K)

8. ♢(∃x){[Q(E!,x)∧(∀F)~(F = E!)]→ ~Q(F,x)]} → ♢☐(∃x){[Q(E!,x)∧(∀F)~(F = E!)]→ ~Q(F,x)]} (3,7 MP)

9. ♢☐(∃x){[Q(E!,x)∧(∀F)~(F = E!)]→ ~Q(F,x)]} (5,8 MP)

10. ♢☐(∃x){[Q(E!,x)∧(∀F)~(F = E!)]→ ~Q(F,x)]} → ☐(∃x){[Q(E!,x)∧(∀F)~(F = E!)]→ ~Q(F,x)]} (Theorem of S5)

11. ☐(∃x){[Q(E!,x)∧(∀F)~(F = E!)]→ ~Q(F,x)]}(9,10 MP)

12. ☐(∃x){[Q(E!,x)∧(∀F)~(F = E!)]→ ~Q(F,x)]} → (∃x){[Q(E!,x)∧(∀F)~(F = E!)]→ ~Q(F,x)]} (Axiom M)

13. (∃x){[Q(E!,x)∧(∀F)~(F = E!)]→ ~Q(F,x)]}(11,12 MP)

14. ~(∀x)(∀F)[(Q(F,x) → B(F,E!,x)] (4,13 MP)

15. ~N (6,14 MT)

*QED*

Posted on December 22, 2019, in Uncategorized. Bookmark the permalink. Leave a comment.

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