Nothing can be trusted to be real, or at least, that’s the starting point. In this episode, I break down René Descartes’ method of radical doubt by walking through the First and Second Meditations, step by step. What happens if you treat everything that can be doubted as false? That includes; your senses, your body, the external world, and even mathematics.

Source of Discussion: Meditations on First Philosophy, René Descartes, 1641.

Dr. Avi Loeb is a prominent theoretical physicist specializing in astrophysics and cosmology. He serves as the Frank B. Baird Jr. Professor of Science at Harvard University, where he previously chaired the Astronomy Department and founded the Black Hole Initiative. He has authored over 800 papers and popular books like Extraterrestrial on potential signs of alien technology. Follow the podcast for more conversations on cosmology, science, and philosophy.

As we enter 2026, I wanted to take a step back and reflect on some of the books I read this year, and what they made me rethink about life, meaning, power, consciousness, and society. Check out the chapter names to see books discussed in this video. Let me know in the comments what you’re planning to read in 2026, and whether you have read any of these before.