Somebody asked me for my thoughts on a concise definition of beauty, so here they are:
First, it’s terribly unfair to ask for a concise definition because the more concise you make it, the more people will understand the words differently.
Second, if you are going to define beauty you have to believe that it actually exists, which means that it is not merely “in the eye of the beholder.”
Third, I do believe that it exists and that it is an essential property of all that is good, just, right, appropriate, etc.
Fourth, that doesn’t make it easier to define.
Fifth, Thomas Aquinas gave a great description of the elements of beauty: wholeness (also translatable as purity, an interesting fact in itself), balance, and radiance (sometimes called clarity, but this confuses the issue – radiance is better).
Beauty therefore is a quality of an object that is most easily perceived when the object is whole/pure, balanced, and radiant.
A word on radiant: for an object to be radiant, there must be something that is “radiated.” That something is the idea being embodied in the object. For example, if you want to see a beautiful painting of a tree, then you must look for a painting in which the idea of a tree is embodied well.
A beautiful tree itself is one that is healthy (whole/pure), balanced (it grows in a proportionate manner, which all trees are created to do so far as I can tell), and radiant (you can see the idea of a tree clearly in this tree because it is a wonderful type of the idea of a tree).
That radiance bit is tough for moderns because we don’t value “ideas” in the Christian classical sense anymore and that is why our culture has experienced an aesthetic meltdown. We think something is beautiful merely because we enjoy looking at it or listening to it.
The entire history and notion of artistic criticism and even moral judgment, however, arise from the notion that there are ideas and that those ideas need to be expressed well (appropriately) for a work of art to be successful.
Art is, in short, not self-expression, but expression of an idea (not a concept in the head, but an idea woven into the fabric of reality).
Beauty, therefore, is one of the most important ideas in existence. And it seems to be, as I said above, a quality in an object that is most easily perceived when the object is whole, balanced, and radiant, and when the observer has “eyes to see.”
One final thought: the Greek word for beauty is Kalos, which can also be translated: the good, the noble, the fitting, etc. Very interesting.