Physicist David Deutsch joins Chris Williamson on Modern Wisdom to apply Karl Popper's epistemology to learning, social media, optimism, AI and education. All knowledge creation follows one process, so learners must guess and test what a teacher means, and failed communication is the communicator's fault. Certainty is no guide to truth, and ideas should be judged by whether they survive error correction, not by authority.
Deutsch defines optimism as the view that failure always reflects missing knowledge, and calls pessimism, like killing every character in a story, as cheap as a deus ex machina. He calls AI doom and climate catastrophe arbitrary picks from endless possible disasters, and says nuclear panic caused today's climate problem. LLMs lack explanatory creativity, so won't produce AGI; grandmasters reason by explanation with about a millionth of an engine's computation. He rejects the bucket theory of education, calls exams poor proxies, and says discipline is good only when it serves what you love.