“As birds have flight, our special gift is reason. Part of that reason drives the intelligence that allows us to master DNA or build big power plants. But our reason could also keep us from following blindly the biological imperatives toward endless growth in numbers and territory. Our reason allows us to conceive of our species as a species, and to recognize the danger that our growth poses to it, and to feel something for the other species we threaten. Should we so choose, we could exercise our reason to do what no other animal can do: we could limit ourselves voluntarily, choose to remain God’s creatures instead of making ourselves gods. What a towering achievement that would be…”

– The End of Nature by William McKibben (1989).