Godfrey Pearlson, a Yale neuroscience professor and author of 'The Science of Weed,' discusses the shifting perceptions of marijuana, its historical stigmas, and the scientific realities of its effects. Ilana Redstone, a sociology professor, introduces the 'certainty trap,' a psychological bias that leads to intolerance of differing opinions. Together, they explore the complexities of cannabis, its medicinal properties, and the importance of questioning our beliefs to foster empathy and understanding in discussions surrounding controversial topics.