He said that these two things (goodness and being) are the same. But they don’t share all of the same characteristics. Which means that they’re not the same. Which gets us where exactly?
It is not that goodness and being have different characteristics, but that the notion of goodness highlights different aspects of the same reality than the notion of being does. Specifically, it highlights the aspect of desirability (and, on further investigation, intrinsic perfection—see below).
it is clear that a thing is desirable only in so far as it is perfect;
I don’t agree with this. I desired to find a husband. But I wasn’t expecting to find a perfect one! Now that I have a husband, it isn’t his perfection that makes him desirable. (Trust me, he’s not perfect.)
Aquinas is using the term “perfect” in a technical sense, not in the modern sense of “absence of all defect.” A thing is “perfect” if it has a some good characteristic;" a “perfection” is the good characteristic in question. “Perfection” can also mean “fulfillment” or “satisfaction” in general, depending on the context.
What Aquinas is getting at is that a thing is desirable inasmuch as it has some characteristic that attracts the one who is desiring. For example, take a fireplace on a cold day. It has a perfection (namely, warmth) that the cold person desires.
Note that for Aquinas “desire” has a much deeper meaning than it does today. It doesn’t mean “whim” or “fancy,” but a real, authentic need.
for all desire their own perfection.
I’m not even sure I agree with this. The striving for perfection is desirable. But once you achieve perfection I think existence would be dull. It’s the striving that makes us who we are.
Again, “perfection” does not mean “absence from all defect,” but fulfillment or satisfaction. All things seek to reach the end for which they were created. For sub-human things, that fulfillment consists in something rather banal (for and acorn, it is to become an oak tree and produce more acorns), but the perfection that man strives for is called
happiness.
I think you would agree that all people seek to be happy, which is Aquinas’ point here. (People may seek happiness in all the wrong places, but they seek it all the same.)
Aquinas takes it for granted that complete happiness is impossible in this life, because only the direct vision of God can bring it about.
But everything is perfect so far as it is actual.
I don’t pretend to understand this bit at all. I don’t see any correlation between actual existence and perfection, unless you change the meanings of some of the terms.
Again, a thing is “perfect” inasmuch as it possesses good characteristics (i.e., “perfections”). A straight tree is more perfect than stunted one; a properly functioning faucet is more perfect than a leaky one; a morally righteous man is more perfect than a morally depraved one, and so on.
Things, on the other hand, are “bad” to the degree that they lack something essential (the stunted tree lacks growth or good health; the leaky faucet lacks a functioning washer; the morally depraved man lacks virtue).
Thus, “perfection” always means “having something,” hence it always entails “actual” being. (Here the “being” in question is the being proper to those perfections, which are accidents. Thus, it is not a question of the mere existence of the things, but the existence of those good characteristics.) “Lack of perfection,” on the other hand, is a lack or privation.