Is there any “proof” that existence is actually good, other than intuition? St. Thomas’ argument seems to go like something along these lines: goodness is what all people desire. This is found in perfection. But perfection has to be actual in order for it to be “perfect”. Everything actual exists. Therefore existence is good.
This is an area where it is hard to get a handle on Aquinas’s terminology.
Actuality is not merely
existence. When Aquinas uses the term
being (especially as a transcendental, ie. “philosophy of being” or characterizing God as “Being Itself”), he usually does not just mean that a thing
exists. Actuality refers to existence
in a certain way. Particularly it has to do with the lack of potentialities relative to a substance’s natural ends (which are inherent in its form).
Take two trees. One is bigger than the other, but is missing a branch. Aquinas would probably say that the one that is not missing a branch has more “being.”
God is taken to be Being Itself because he lacks any potentialities. (This must needs be analogical, as well, since God does not have ends like we do; He has a nature, but it is not a nature which He, or anyone/anything, can do anything to
improve.)
This is an interesting basis for metaethics and aesthetics. Good is a transcendental; it is the
aspect of being as desirable. In other words, it is being (actuality) viewed by an intellect as desirable, ie. it is the recognition (say) that it is better for a tree to have a branch than to be broken. Now, someone might perversely believe that it is better for trees not to have branches, and so he regards branch-less trees as more good. But since the both being and good are rooted in the natures of things (even if good is a conceptual distinction, an aspect, of being), he is wrong, and he has misapprehended the good.
Truth is also a transcendental notion and fits roughly into a correspondence theory. The correspondence of intellected forms with actual forms is what truth is. As such, it too is rooted in the real natures of things, and is an aspect of being.
I think this is a powerful account, augmented by a good theory of analogy. Does it make sense to say that being or truth are analogical? The analysts may not think so; they might feel that being is captured in the existential quantifier over an arbitrary domain, that truth is rooted in the attribution of a boolean value to a proposition. I don’t think we have to give such tools up, though. It makes sense to say that
being is analogical. To say that there are separate modes of being is a fruitful analysis: there are substances, which are ontologically primary; there are accidents, which exist only as inhered in substances; there are universal forms, which exist only in the intellect; there are
entia rationis, beings of reason (like the rules of logic, subjects and predicates, complex mathematical apparatuses like matrix algebra and group theory), which exist in the mind but are not real forms that have instances in the world.
Truth is analogical because it is what corresponds to these different varieties of being; I have true knowledge of my cat in a different way than I have true knowledge of multivariable calculus. The idea also allows us to accommodate what probably constitutes the vast majority of human knowledge. If I have never seen a cat before, and I sit down to play with a cat, I learn quite a bit of knowledge. It is propositional in the sense that it consists in subjects and predicates, but it is not sentential or verbal, and I likely could not express everything I would come to know. Moreover, if I went on to study cats formally in the specialized science of biology, I would learn quite a bit more. As the intellected, universal
form of
cat in my understanding better approximates what actual cats are, I am approaching the truth.
And
good is of course an analogical notion. Compare the uses of: It’s a good tree. It’s a good cat. It’s a good knife. The emotivists took the difficulty in defining and analyzing good to be reason to cast doubt upon it and demote it to subjectivity. But that is an impoverished account.