This post is more exploratory than something I am confident of.  The medieval scholastics had a concept called the “convertibility of transcendentals” (CoT), in which certain terms (e.g. “good”, “true”, “one”, “real”) are all in a certain sense interconvertible with each other.  In this post, I wish to explore the implications of this idea.

Sometimes we use the phrase “a good X” to mean an X that is more fully an X.  A good drawing of a circle is one which is more uniformly round (closer to being a perfect circle) than a sloppy circle is.  This depends on the prior judgement that you actually wanted the drawing to be a circle rather than something else (e.g. an oval, or an outline of a pumpkin).  That is one sense in which goodness might be considered subjective; yet it is not inconsistent with saying that when we see an object as good we are seeing something objectively true about it, nor does it commit us to saying that all ways of perceiving objects are equally fruitful and meaningful.

From a hypothetical imperative perspective, whenever you want an X as an X, then what you want is a good X, which is the same as a true X.  (Although we are more likely to say “good” when X-ness is a matter of degree, and more likely to say “true” when it is a yes/no question. In this linguistic sense, goodness is more subjective than truth.)  CoT takes this usage of the word “good” as being a clue about the nature of what is categorically good, i.e. that which we morally ought to want.

Scholastic definitions: Goodness is being, insofar as it is capable of being willed.  (Just as truth is being, insofar as it is capable of being known.)

CoT commits one to the surprising claim that everything that exists is good, simply because it exists, even though it does not deny that some things may, on top of that, also be (truly) bad.  (Linguistically, a true evil is an evil that really is evil; one could even call it a good example of an evil even though we would probably balk at calling it a good evil!)  More precisely and less paradoxically, each thing is a good X for some value of X, but this is compatible with it being both bad for itself under another (and more important) description Y, and also bad for other things in the universe; hence good for us to condemn, eliminate, or reform.

For example, a good thief is somebody that fully succeeds in being a thief.  (E.g. if you hire a thief but he gets caught and has to return the goods, he has failed to steal anything in the desired sense.)  In this respect:

good thief = true thief = real thief.

If we make a moral critique of theft (and we should) it can only be because by being a good thief, he thereby fails to be a good member of society, and thus also fails to fully actualize his nature as a human (a rational social animal), which is more essential to him than his nature as a thief.  Thus:

good thief => bad man = false man = fake man.

Sin is then, the fact that humans can act as if they were not humans.

Taken to the extreme, damnation is the possibility that by becoming permanently attached to sin, a human being could eventually cease to be human in some crucial respect, thus making happiness impossible for them (insofar as they cannot fully cease to be a sort of thing that can only be happy by being human, even as they fail to be human).

On the other hand, Heaven is the fulfilment of human personhood, which (in the Christian account of virtue) essentially includes union with the divine.  This is, among other things, a statement about the best (most good, most true) meaning of the word “person”, namely that personhood is a way of being in the divine image.

Persons have intellect and will.  CoT implies that these faculties are (or at least ought to be) in harmony.  Just as truth is the goodness of the intellect, so too, goodness is the truth of the will.  CoT thus puts reality in an essential relation to personhood.

The convertability of transcendentals, if true, makes Theism more plausible, and vice versa.  God is analogous to a person, in that he has something analogous to intellect and something analogous to will.  However, unlike us, his intellect just is truth, and his will just is goodness.  Also, in God these two faculties are the same as each other.  God is the only being that has existence in himself; in other words the only being that is completely a being.  Hence, by CoT, there is also a sense in which only God is good (cf. Mark 10:18).  Other beings are said to be good only insofar as God shares his being with them, which is creation.

To be created, is nothing more nor other nor different, then to be known by God (as other than God). To be created, is nothing more nor other nor different, then to be loved by God (as other than God).

A Naturalist is somebody who believes that reality (the Universe) is convertable with truth (“Science”), but that it is not convertable with goodness (“Fiat lux!”).  Naturalism in this sense makes it exactly half way towards Theism.  Therefore, Naturalism is only 50% true and 50% good.

Since persons have both intellect and will, a Naturalist is necessarily alienated from their own personhood, and internally divided against themselves.  If they allow their Naturalism to influence their self-image, then they will regard their morality as false (hence not really moral).  Alternatively, to the extent that they cannot allow their Naturalism to influence their self-image (and arguably humans are mentally incapable of fully accepting all the implications of Naturalism) then they regard what they take as true to be bad for their self.

Hence Naturalism is unavoidably bad for us, since it is incompatible with full human flourishing.  From the Theist perspective, this is a convincing intellectual (not just pragmatic!) argument that Naturalism is also false (since for the Theist the deepest reality is always good).

But from a Naturalist perspective, this doesn’t count as an argument that Naturalism is false.  Since the Naturalist believes that the deepest reality cares nothing for goodness, and hence there is no good reason why believing the truth cannot be bad for us.

Yet almost all Naturalists instinctively assume that if Naturalism is true, it must also be good to convince others it is true, and healthy for society to reject beliefs incompatible with it.  And indeed, if Naturalism were true, I believe it would be less bad to believe it than to believe a pious falsehood, even at the price of being divided against oneself.  Since “good” in reference to the intellect means “what the intellect seeks”, i.e. the true.  Also, a false belief cannot be a worthy foundation for society since a person with false beliefs will systematically act imprudently, in ways that are harmful to others (because their data is bad).  So I would want to believe Naturalism if it were true, although perhaps this only implies that even Naturalism wouldn’t be capable of causing me to stop believing in something that amounts to the CoT.

Some additonal linguistic evidence for CoT:

* English speakers use the words “right” and “wrong” to refer both to true/false and good/bad.

* We also use the word “belief” both to refer to thinking that something is true, and to our beliefs about morality.