Why would you expect even to recognize, much less be able to understand, the art of a spider? What arrogance gives you to imagine that our terms can suffice to capture their experience, or vice versa?

I can't speak to spider art, but I can somewhat to spider smarts. We hosted an orb weaver on our porch this year, and she found the best place to build her web for prey capture was right across the porch steps. Unfortunately, this also led to importunate apes occasionally blundering face-first into, and thus disarranging, her careful work - even when you're trying not to break anything, you can't help but snap a thread or two in disentangling yourself.

So, after a couple nights studying the problem, she started building her webs shorter but wider and higher up, maintaining roughly the same capture area but keeping the structure a good couple inches above human head height. (Or my and my boyfriend's height, anyway, we being both about 5'10".) She kept that up the rest of the season, and we got along just fine - I've had human houseguests who were less courteous and less skilled at finding a modus vivendi.

This idea comes from Mechanical Philosophy, and is represented in the writings of Descartes. According to his dualist view of the world, the soul and body are opposed, but only humans have a soul.

He wanted to show that animals are just automata, and believed that they are incapable of feeling pain.

Probably just evolution. Contemplating the morality of eating antelope doesn't help the lion survive. Assuming that antelope are for eating does.