Physicist David Deutsch and astrophysicist Martin Rees debate the role of knowledge and technology in shaping humanity’s future. Deutsch argues for epistemological optimism, stating that all problems stem from lack of knowledge, while Rees expresses technological optimism but political pessimism, warning about potential catastrophic risks. Audience members share diverse perspectives on issues like inequality, ethics, governance, and the need for public discourse to guide scientific progress responsibly. A lively exchange highlighting the complex interplay between knowledge, technology, and social factors in navigating an uncertain but potentially promising future.