“The Earth may remain habitable for at least a billion years. What has occurred so far is at most a tiny fraction of possible human history. Nor should we restrict this question to the lives of future human beings. just as we had ancestors who were not human, we may have descendants who will not be human… Our descendants might, I believe, make the further future very good.”

— Derek Parfit, On What Matters: Volume 2 (2011), p. 616