Wednesday, July 3, 2013

Reintroducing the Basic Metaphysical Argument for God's Existence

I refer to the argument in St. Thomas Aquinas's small tract, De Ente et Essentia, as a "metaphysical argument," as opposed to a cosmological or ontological argument, since neither of the latter descriptions appear to me adequate to describe what Thomas is getting at.  To be certain, the metaphysical argument is a posteriori, since it begins with the observation that something exists.  Here's how I simplify the argument:

1. Something exists. (Premise)

2. Something exists if and only if being exists. (Premise)

3. Therefore, being exists. (From 1 and 2)

I use the expression "being exists" in order to avoid the redundancy of saying that "existence exists."  Nevertheless, "being" is used synonymously with "existence."

Premise (1) is quite obviously true.  For example, in order to doubt my own existence, I would first have to exist in order to doubt it.  This is along the same lines as Descartes's cogito ergo sum, or "I think, therefore I am."

Premise (2) is more controversial.  However, I'm not at all impressed by the objections to it.  Kant asserted that existence is not a predicate.  But, why should we agree with such a contention?  What, for instance, is the difference between something real and something not-real?  If being does not exist, then the difference between something real and something not-real is literally nothing.  This means that what is real is identical to what is not-real, which is absurd.

Thomas continues by deducing some of the divine attributes of being, or "being itself subsisting."  Being must be eternal and omnipresent, since there is no time or place at which being does not exist.  If there were no being at some time or place, then nothing would exist at either time or place.  Moreover, being must be unique, or one.  If there were more than one being, then there would be distinctions among them.  However, to be distinct from being is to be non-being, in which case the latter does not exist anyway.  Being is a thing's existence or actuality.  The reason why things are able to be distinct from one another is because they possess distinct essences.  The essence of a thing is its nature.  This means that everything that exists participates in one being, but can be distinguished by their various essences.

Being must also be immutable, since to change from being to anything else would result in being's becoming non-being, which is self-contradictory.  Next, being must contain within itself all perfections: omnipotence, omniscience, and moral perfection.  If it did not possess these attributes, then being would exhibit potentiality, which is impossible for something immutable.  Changing things exhibit actuality and potentiality, just as the acorn is merely an acorn in actuality and an oak tree in potentiality.  Being itself must be Pure Actuality as a result of its immutability.

Therefore, I maintain we have a sound and rationally compelling argument for the existence of an eternal, omnipresent, unique, immutable, omnipotent, omniscient, and morally perfect being.  This, as the Angelic Doctor muses, everyone understands to be God.


  1. I've long found it amusing that Ayn Rand imagined she had disposed of God by saying "Existence exists", and this truism is all the explanation necessary to explain or ground the existence of the world and all in it.

  2. It's definitely amusing, to say the least. She's borrowing a Thomistic concept in order to undermine theism. That's like denying the sun's existence while basking in its rays.

  3. I really like this article alot! I have three issues though, that I would be grateful if you (Doug) (or anyone) would clarify:

    1. In response to "To be distinct from being is to be non-being, in which case the latter does not exist anyway."
    While I agree that in order to be entirely distinct from being, something must be non-being (which is the same as saying that something that is entirely distinct from being does not exist, or nothing entirely distinct from being exists), I have difficulty seeing why something cannot be partially, yet not fully, distinct from being? Doesn't this occur when something exists but also has a distinct essence, like a dog; so that a dog is (being + dog) and so is partially distinct from being itself (just being), in the same way that a full plate (plate + food) is distinct but not entirely different from an empty plate (just plate)?
    2. If something's essence is the same as its existence, then is that not the same as saying that that something really has no essence, but purely exists?
    3. If God (in His Divine Nature) is sheer existence, and existence is something predicable of anything that does exist (for example, "a dog exists"), then how is it that God is not something predicable of anything that does exist, since, according to this, He is existence? (Basically, how do we hold that God is being itself, yet avoid Monism and Emenationism?)
    [a. God is (in His Divine Nature) existence itself
    b. My dog is made up of existence (existence itself) and a dog essence.
    c. My dog is made up of a dog essence and God (c. substitutes 'existence itself' for God, which is equivalent).
    c. is false, but how?]

  4. Hi Richard,

    Thanks for your comments! Taking your questions in order:

    1. I rather subtly allude to this when I say, "everything that exists participates in one being, but can be distinguished by their various essences." A dog has an essence that is distinguished from its being, which is to say that it does not exist essentially/necessarily. What I love about the argument in De Ente is that it makes sense out of "the one-and-the-many problem." Things are alike insofar as they participate in one being, and they can be distinguished by their plurality of essences.

    2. I wouldn't put it that way. When we say that God's essence is the same as his existence/being, this is a reference to God's simplicity: that God is not composed of distinct parts. It also means that God has necessary existence, whereas anything distinct from "being itself subsisting" is contingent and in need of a cause. From, "God's essence is the same as his existence," it cannot be validly inferred that God has no essence.

    3. Since God is a noun, the parallel to "my dog exists" would have to be "my dog has existence." This would mean, "my dog has God" which, while awkward sounding, is also in line with both Greek and Biblical thought. After all, it is in God "we live and move and have our being" (Acts 17:28, where the Apostle Paul, during his debate with the Athenians, cites Epimenides).