Humanity could survive for millions of generations—enough time to end disease, poverty, and injustice, and reach new heights of flourishing. But this vast future is at risk. With the advent of nuclear weapons, humanity entered a new age, gaining the power to destroy ourselves without the wisdom to ensure that we won’t. Since then, these dangers have only multiplied, from climate change to engineered global pandemics and the potential for highly capable unaligned artificial intelligence. If we do not act fast to reach a place of civilizational security, it may soon be too late. In this class, we will attempt to answer some key questions relating to existential risk — the risk of a catastrophe that would permanently end civilization and curtail humanity’s future potential: - What is the likelihood of civilization collapse in this century? What are the most likely causes? - How good could the future of human civilization be, barring disasters? - What are the best ways to mitigate existential risks?