Beware underestimating the probability of very bad outcomes: Historical examples against future optimism

It may be tempting to view history through a progressive lens that sees humanity as climbing toward ever greater moral progress and wisdom. As the famous quote popularized by Martin Luther King Jr. goes: “The arc of the moral universe is long, but it bends toward justice.”

Yet while we may hope that this is true, and do our best to increase the probability that it will be, we should also keep in mind that there are reasons to doubt this optimistic narrative. For some, the recent rise of right...