Wisdom from a netfriend:

*All* the European colonists started from the premise that human beings could “own” land; the indigenous peoples from whom they “bought” the land didn’t think that way in the first place. Land as private property was – well, rather like thinking of air as private property. Imagine extraterrestrial aliens coming in as colonisers and saying they can dictate where you’re allowed to breathe, and they can buy and sell “breathing areas”. Doesn’t make sense, does it?