In reply to:
You often hear artists talking about how their art--or art in general--can "change the world."
No I don't.
I don't disagree with your general point, I do think calling anyone who takes such a stance pretentious is a fair application of the term. However, I generally only see such illusions of grandeur ascribed to artists by others, but rarely from the artists themselves... Off the top of my head, I can only think of one example that seems to fit that (Ayn Rand), whereas the list of artists who don't publically think that way is almost endless.
Artists who aspire to take part in the changing of the world, so to speak, are another matter entirely. Art can be an integral part of social change (see Bob Dylan, Hunter S. Thompson, Barbara Kruger, et cetera), so that sort of ambition seems pretty reasonable, to me.
Further, I think you overestimate the number of artists who have any sort of social agenda, or any other remotely revolutionary outlook on their work.The vast majority of artists I've known simply want to give people something interesting or enjoyable to look at or to think about or whatever. The popular image of artists seems to be that they sit around saying "Look at me! Aren't I great?", whereas most real artists are sitting around saying "Look at this! What do you think?"
Can you feel it? Can you feel it?