One HBLer said that to be a fine art something had to meet requirement R.
Another HBLer gave a counter-example: architecture doesn’t meet R but is still a fine art.
The counter-example approach is not a good one, except in the fields of math and logic because they don’t require weighing competing factors in a complex whole.
When someone makes a philosophic claim, a single counter-example does not at all refute the claim. It does provide a reason to think about the issue, but doesn’t call the claim into doubt. The reason is that the counter-example could be:
1. A clear refutation of the principle
2. A special case to be handled as such, which doesn’t refute the principle
3. A misinterpreted case that actually does not serve as a counter-example
An example of 1: “You say religion is the only base for morality, but Objectivism has a full moral code without religion.” Notice that this only forestalls questions on both sides: 1. Really?! How, based on what? 2. Why do you think religion provides any base for morality? What does “morality” mean to you? So the relation of the counter-example isn’t clear and thus even this prima facie proper counter-example settles nothing.
An example of 2: “You say everyone under capitalism could deal with each other by voluntary consent and free trade, but a four-year-old can’t.” Obviously, this is context-dropping. Or, “Ayn Rand defines capitalism using the phrase ‘all property is privately owned,’ but the tanks of the military and the White House aren’t.”
It doesn’t really matter whether you reply by saying that this is an exception, and definitions don’t have to cover every case (which is true), or you reply by saying that in some sense these things are owned by the voluntary financers of the government (which may be true, I haven’t decided); either way, the counter-example does not show anything one way or the other.
An example of 3: “A complete separation of state and economics? Then there’d be no Bureau of Printing and Engraving and no government currency!” Here the answer is: “You bet!” Another example: “If everything were voluntary, then there could be no law and no government.” There, the conclusion drawn is false, and the person needs to told about the distinction between initiated and retaliatory force.
So, in no case does a counter-example bring understanding—at best, it provides material to think about. At worst, it’s a distraction.
Now in the case of architecture, the first thing to ask is: “How can one be sure it is a fine art?” I doubt that it is. And if it is, it is still “a special case.”
But the counter-example overlooks the huge difference between using beautiful calligraphy on an existing poem and using architecture to create out of whole cloth one’s own answer to the assignment (“build a home for a family of 4 on this hilltop”). Architecture is not re-modeling. The David is Michelangelo’s creation out of whole cloth (or whole marble) even though it takes an existing legend as its subject.
The David is not a decorative rendering of something. Neither is Wright’s Fallingwater. But Wright’s furniture inside his structures, though stylized by his sensibilities, is still a way of presenting a utilitarian object whose overall shape leaves limited scope for variation.
A final thought: borderline cases do exist. There are things that are difficult to judge as to whether they are fine art or decorative art. A good example is movie music. Some of it is clearly free-standing (Raindrops are Falling on My Head, Carousel Waltz from the Rodgers and Hammerstein musical), but some of it has to be judged as not (the familiar shark-approaching theme from “Jaws”). But what about sections of movie music like the theme from Star Wars or Rocky?
My point is that those are just like ITOE’s example of reddish orange: they are borderline cases whose classification is optional.