One of the arguments that environmentalists use against factory farming and burning fossil fuels is that these activities are "unnatural" or that they "go against nature." But what exactly is this "nature," and who gets to define it? The answer is that nature actually comes from culture. In the west, many of our common sense ideas about nature can be traced back to a debate that brewed between political philosophers in the seventeenth and eighteenth centuries. Their debate, which is by no means settled even to this day, centered on human nature. Are we inherently evil and greedy, or inherently good and altruistic? To answer, philosophers 300 years ago turned to what were then called "savage" peoples, mostly Native Americans, trying to figure out how humans acted in a "state of nature."