claim: This requires us to work towards avoiding catastrophic possibilities rather than looking at probabilities, as learning from mistakes is not an option when it comes to existential risks.
evidence: Nick Bostrom argues that it would be misguided to assume that the probability of near-term extinction is less than 25% and that it will be a tall order for the human race to get our precautions sufficiently right the first time, given that an existential risk provides no opportunity to learn from failure.