John Cottingham, a renowned English philosopher and Professor Emeritus at the University of Reading, dives deep into the world of René Descartes. The conversation uncovers Descartes' radical skepticism and the famous 'Cogito ergo sum.' Cottingham discusses the intricate relationship between perfection, knowledge, and God, exploring how our understanding of existence informs our beliefs. They also address the duality of mind and body, the historical significance of the pineal gland, and Descartes' controversial views on animal thought, all while reflecting on the enduring impact of his ideas.