I'm just curious, what is the basis that animals don't possess a soul?
I'm not Catholic, but I don't believe animals have souls simply because that's the exclusive right of humans, being created in the image of God and all. If Genesis is to be believed, that is -- which, clearly, is up for debate.
We humans, having souls, reason, and consciences, are supposed to be stewards of the earth and all its inhabitants, caring for all God's creatures, especially those who lack opposable thumbs and higher thinking skills. Unfortunately, a lot of otherwise comitted Christians have forgotten this bit.
Do we get to eat animals? Yeah, because they don't have souls and God made them of meat for our benefit (again, Genesis). Do we get to raise them in abominable conditions, shoot them full of hormones and drugs, and beat them with sticks when they don't behave exactly as we'd like? No, because they also feel pain and fear. It seems pretty clear to me, and I don't know why there seems to be this cultural divide between right-wing fundamentalist Christians and hard-core environmentalists. Caring about the planet should be tied closely to Christianity, I can't figure out why a lot of Christians seem offended by the very concept of environmental awareness.