I really prefer Anselm’s argument from gradation in his
Monologium. It’s almost identical to Thomas’s fourth way. A simple version might be:
- If there are flaws in a thing’s goodness, this can only be known by a standard of supreme goodness. (Premise)
- There are flaws in a thing’s goodness. (Premise)
- Therefore, there is a standard of supreme goodness. (From 1 and 2)
This isn’t just a moral argument. The goodness mentioned refers not only to moral goodness, but to things that are objectively valuable. The argument has a Platonic spirit to it, and Anselm concludes that God exists as the Supreme Good. Anything that participates in goodness does so because God’s goodness is imbued in it.
Anyway, it’s not my favorite argument, but it’s worth a look.
St. Thomas’ Fourth Way is probably the most rigorous proof for God’s existence, but also the most difficult to understand. And unfortunately, St. Thomas makes only a brief outline in the
Summa and expects the reader to fill in the details. It is certainly Platonic (more precisely, Neoplatonic) in flavor, but it relies on concepts that neither Plato nor Aristotle had developed, at least not explicitly.
(In particular, neither Plato, nor Aristotle, nor the pagan Neoplatonists had an adequate understanding of creation.)
I don’t think it is the degrees of perfection that interest St. Thomas so much as the fact that these degrees of perfection are evidence of a
participation of creatures in the being (Latin:
esse) of the Creator. Or, conversely, it is evidence of God’s communication of his
esse to His creatures.
All of the perfections mentioned in the Fourth Way (goodness, truth, nobility) are properties that Thomas calls
transcendentia, but that subsequent Scholasticism calls “transcendentals.” They “transcend” the division of being into Aristotle’s ten categories: in other words, they can be properly attributed to any being, although of course their meaning changes according to the type of being. (It is not exactly the same thing to say “God is good” as to say “Charles is good,” or even to say “this pizza is good.” Nevertheless, the meanings are not
completely divergent; there is something in common among all of them.)
The important thing here is that the
transcendentia are in proportion to what Thomas calls
esse (the Latin infinitive for the verb
to be). For Thomas
esse is not simply “existence,” the mere “fact” that something exists, but is much more profound than that: it is the fundamental
act of every being. (What does this rock do? Well, before it does anything, it
is.)
This act comes in various intensities, and it is precisely the intensity of the act that explains the differences in goodness, truth, and nobility in the world: a thing is
good to the degree that it
is, and so on.
As regards a proof for the existence of God, the
variability in intensity of goodness, truth, and nobility that we find in the world is evidence of the variability in intensity of
esse. This, in turn, indicates that the
esse in the world is always limited (otherwise, it couldn’t be any greater than it is). A being with a limited
esse does not have the power to communicate its own
esse to another being, nor can it give itself its own
esse, nor can it be eternal (because limitation is only possible when there is a potential principle in the being, and that potential principle has to be put into act by something outside itself).
It follows that all beings in the world have received their
esse directly from Something that is the Source of this
esse, that possesses
esse as His own (not as received from something else), and that possesses
esse in an unlimited way.
We could sum it up like this: “There are all kinds of good/true/noble things in the world. They could, however, always be better/truer/nobler (or worse/less true/less noble). Things are good/true/noble to the degree that they
are, hence things in the world possess an intensity of being (
esse) that could always, in theory, be greater (or less). Hence, the being (
esse) of the things in the world is limited. But being (
esse) is a type of act, and acts can only be limited by potencies. Moreover, potencies don’t just become “activated” all by themselves: some other thing in act has to come and activate them. Hence, the things in the world are not the source of their own being (
esse). (That is, they
participate in the
esse of Something else.) The
esse of everything in the world must, therefore, be communicated by a (unique) Source that possesses its own
esse to an unlimited degree.”
As I said, rigorous, but somewhat difficult to understand.
