Ah, the ongoing great battle between whether something is an 'art', a 'science' or 'engineering'. Geeks, more than anyone else, love to fight this one out.
I read Knuth's take, hiding over at Paul Graham's site:
I find that his definition for the word art is a huge let down. Art, in the way he writes about it, is really just the unstructured act of doing anything. If it ain't organized, then it must be art.
That, as history shows, is a reasonable use of the word, but it is depressingly cold. It is so because there are more dimensions to human existence than just being. We straddle these wonderful worlds of emotion and thought, sitting on the fence in between.
Our emotions form primitive reactions to the world around us. They are, in all sense, the very opposite of logical thought. They drive us to do crazy and irrational things.
It's not hard to guess that we're actually in the process of evolving from primal emotional creatures to higher forms of logical entities. These days we're caught in the middle. We can be rational and think our way out of the problems, but we can also succumb to crazy emotional responses. This leads to a duality in our perspective. The natural order of things, is an emotional sense, with its rules about the survival of the species. Our intellectual order, is about higher values such as justice and fair-play. Abstract concepts that seem out of place in the real world.
It is emotion, I truly believe, that when rendered into a tangible form sets some constructive act apart from the others. A building houses us, but a majestic one takes our breath away. A graphic designer makes pretty images, but a great painter endows them with that full sense of being. A singer might belt out the notes in tune, but a talented musician can bring tears to our eyes. Any person can stand up and say a dialog, but an actor makes us believe that they feeling it.
Again, and again the differences come down to how various people have crossed beyond just an act, and have found some indescribable way to add emotional context to their work. They touch us at our very core. They reach out to our primitive side.
And, to make it even more interesting, because it is some low-level reactive nature within us, it is virtually impossible to wrap it in a logical foundation. You can not say it, teach it, or pass it on in any concrete manner. It must be felt to be understood, and experienced to be copied. It is beyond our rational thought.
The problem with Knuth's practical definition for the word 'art', is that it does not distinguish between those things that just are, and those that have gone well beyond. It makes it reasonable to talk about the 'art of knitting a sweater' for instance. While that does pay homage to the skill required to actually do the work, it indirectly puts the sweater along side great classic works. Works that inspire emotion in ways that a sweater never could.
Personally, I think the term art, when it is applied in the narrower modern context should only refer to those things that connect with us on an emotional level. We need to distinguish between ordinary stuff, and those great works that enlighten us in some ethereal way. If we use one term for both, we will quickly lose all of our art in a sea of pretty pictures, and that would be sad.
There is something that should be appreciated in people using their skills to create things in an unstructured manner, but it is a rather common event. It happens all the time, all over the world. Artisans craft wares, artists create masterpieces. Art, at least in the sense that I mean it, is a rare and wondrous event. We lose some of ourselves when we fail to recognize that.