Yes, thanks to NS for that poem, never seen it before.
Thanks also to Gonners and Bramble for your points. I didn't think that Proulx was saying that Christianity started the split between man and nature, I agree that that predates Christianity, and is also something fairly unconscious. I mean, humans didn't wake up one day and think, hello, I'm separate from that tree, let's cut it down. They had to cut trees down really.
Anyway, I thought that Proulx was suggesting that Christianity helped in the physical destruction of pagan people, and their religions. The obvious example is Native Americans, but there is also the Baltic crusades, which seemed to destroy pagan culture in places round the Baltic, e.g. Lithuania.
But even here, it is a fuzzy idea. You could argue that colonialism goes around around destroying such tribal cultures, as in the Amazon today, and while Christianity provided a rationale for this, I don't know if it was the main driving force. But then again, I don't know much about this part of history; you hear that in S. America, the priest baptized the pagans, just before they were slaughtered by soldiers. Or is this a myth?