Imagination has always been something that interests philosophers—John and Ken open this episode by discussing the views on imagination held by Hume and Descartes. After elaborating on the philosophical aspect of imagination they get some input from a scientist: Professor Alison Gopnik, a returning guest of the show, joins John and Ken to help puzzle out the role of the imagination in childhood, in adulthood, and in philosophical discussion. What exactly is imagination? Gopnik offers her perspective, which differs from that of John’s favorite philosopher, David Hume. Ken pushes Gopnik to explain why everything around us is imagined, and what makes for productive imagination. Gopnik explains why Harry Potter exemplifies the way we construct imagined worlds, and Ken tries to sort out whether traveling at warp speed fits the model.

约翰，肯和戈普尼克继续讨论反事实，或者说是如果事情与实际情况不同会发生什么。他们争论“几乎”的意义，以及为什么几乎完成一件事会比没有完成更伤人。听众加入讨论，质疑想象力与失明、抑郁、灵感、概括和教育的关系。戈普尼克谴责狄更斯式的反派人物反对想象，我们的主人提醒我们，爱因斯坦并不擅长数学;他很善于想象。

The show concludes with a discussion of how the role of imagination changes over the course of one’s life. As children, we live in a free space where all we have to do is think. Gopnik suggests and evolutionary division of labor between old and young, and explains why time spent daydreaming is far from wasted. Ken poses one final question for Gopnik, wondering whether we can imagine the impossible.

• Roving Philosophical Report(seek to 4:20): Polly Stryker speaks to experts in imagination—Jane Perry at UC Berkeley’s Child Studies Center, and, naturally, children. Both Perry and the children explain the value of games, and Stryker finds out that her favorite childhood pastime is still cool. Perry lets Stryker know what she’d say to anyone who discourages children from letting their imaginations roam free.

• Philosophy Talk Goes to the Movies(seek to 48:15): John and Ken have a suggestion for you if you’re feeling the need to kick back and watch a film: Woody Allen’sMatchpoint．虽然这部电影没有明确地聚焦于想象，但它有很多值得思考的哲学素材，尤其是关于运气的。除了基本运气这一基本问题，这部电影还提出了道德运气的问题——例如，杀死自己爱人的男人是否比可能杀死爱人但从未陷入这种境地的人更坏?最后，关于宇宙中是否存在正义的问题——看看约翰和肯是怎么说的。然后看电影，自己思考。