Jonathan, you make some good points and perhaps I should have said "conventionally useful" instead of useful. I stand by my statement though. The purpose of art is not documentation. I can do a painting of a mountain and you can stand next to me and take a photograph of it. The photograph documents the appearance of the mountain on a certain day from a certain viewpoint. The painting documents the experience of looking at a mountain on a certain day from a certain viewpoint. On the face of it, the photograph is much more successful in conveying the appearance of the mountain. In actuality, the painting conveys its essence, not just its appearance. A painting doesn't tell you what a mountain looks like, it tells you what it's like to look at a mountain.

If the purpose of painting were solely to document visual reality, it quite rightly would have ceased to exist with the advent of photography.

I think the post above yours proves my other points. The writer points out how useful photography and computer graphics are in conveying information about their product. The purpose of art is not to convey information, it is to convey the artist's direction apprehension of reality, whether interior or exterior.

Art is "conventionally useless." From another viewpoint however, it is the most useful, the most valuable thing in the world.

Marc