I must say, it's refreshing to see the presence of actual debates on the blog. Sometimes it's nice to know I have more than one reader.
Still, I thought I'd toss out my final thoughts on the subject and then move on. Well, I'll move on. Everyone else can feel free to discuss it as you please.
My own approach to animal intelligence is largely experiential. I don't know much about the scientific studies regarding the field (animal ethology, apparently). Still, this article from wikipedia on animal cognition was somewhat helpful. What did I take away from it?
1) The people who actually study this are, apparently, divided. They can't seem to decide whether animal intelligence is just an illusion of mechanical responses that simply seem intelligent, or actual reasoning skills. They don't know if the cognitive processes are similar to ours or not. They argue over the proper way to interpret experimental results.
2) They still don't compare to humans. Not that I needed the article to tell me this, but it's nice to know. The fact of the matter is, however much intelligence you want to attribute to an animal, it will never, ever compare to that of a human being. We can argue over whether that is a difference in degree or type, a distinction Ryan was right to make. But the difference is there and it can't be ignored without a degree of intellectual dishonesty.
3) The argument has gotten away from my initial point. The initial idea was, "Why is human life more valuable than animal life?" I defended it with a reference to intelligence based on the inifinite potential that human intelligence represents. Whatever animal intelligence may produce, it offers us no benefits. Animal intelligence tends to produce only further survival for the animals. Human intelligence, on the other hand, produces all those things I defended as products of man's intelligence: society, culture, music, art, technology, science, medicine.
Thus why human life has more value than animal life. As I see it, the only real way to discount this is to render all accomplishments of civilization meaningless, a resort to nihilism.
And unless this discussion takes a turn that sparks my interest, that's all I have to say.