Are human beings born completely empty, with no instincts or preloaded traits, so that everything we know and fear comes from experience alone? This episode traces the idea of tabula rasa from its literal origin as a scraped Roman wax tablet through Aristotle's unscribed tablet, the Stoic wax metaphor, Ibn Sina's empirical abstraction and Ibn Tufail's feral-child novel Hayy ibn Yaqzan, then into Aquinas, John Locke's white paper and the political revolution that followed when blankness came to mean equality and natural rights.

The conversation then turns to the science that pushed back: neurobiology showing a cortex organized from birth, Chomsky's universal grammar, behavioral genetics on IQ and addiction, and a 4D ultrasound study of twin fetuses that found intentional social movements toward a co-twin from the fourteenth week of gestation ...