1.) If you have two identical pieces of stone, the one being uncut and the other sculpted by Bernini, the first is unremarkable and the second is beautiful. If you have a series of sounds and another an ordered melody, the same is true. Thus, beauty is from form or structure.
2.) Form or structure also exists in the mind of the artist who makes
3.) Thus, some beauty exists in the mind that makes.
4.) The beauty in the mind that makes more beautiful than the beauty in the thing made.
5.) Objection 1: that for the sake of which something exists is better than it alone. But the artistic form in the mind exists for the sake of making it.
Objection 2: What is completed is better than what is initial. But the artistic work is a completion of the idea.
6.) A thing can be desirable for various relative perfections without being better absolutely. A picture of Hawaii is more permanent and more able to be shared than an actual experience of the place, and so we take pictures of it. But this does not make the picture absolutely better than the thing it is a picture of. This is the situation we are in with respect to the form in the mind and the artifact made from it.
Art has various relative perfections to the idea in the artist: it is more manifest to sense (even the senses of the artist); it is usually more permanent and stable than his thoughts; it is more able to be shared with others. But if we had a choice between seeing the artists work and being able to enter into his mind, so as to see the work from the inside, and to know the exact significance, structure and meaning it had to him, we would choose the latter.
7.) As art makes, so does nature. Thus the blueprint or logos from which nature brings things forth is more beautiful than the thing brought forth by it.
Confirmation: we would prefer to see the for ourselves the inner idea that brings forth a natural thing than the thing itself. No one would pay to just look at the universe, but to see the logos or law that generated it is something far more dear.