"COVID-19 is clear and unequivocal evidence that population density has reached unsustainable levels. We are looking at The Great Filter." You are aware of cou

"COVID-19 is clear and unequivocal evidence that population density has reached unsustainable levels. We are looking at The Great Filter." You are aware of course that there have been other plagues in the past, going back to at least the Roman Empire: the Plague of Justinian, shortly after the fall of the Western Empire; and nearly a millennium before that, the Plague of Athens. Just how small does the human population have to get, in your opinion?