John and Ken start off the show, as they so often do, by defining terms. They use Hume’s theories to tease apart the concept of a feeling versus that of an emotion. John illustrates how an emotion can be viewed as a complex composite of its cause, its target, and the accompanying feeling, such that one feeling can correspond to many different emotions.

在Ken热情洋溢的介绍之后，Paul开始描述他在微表情方面的关键发现。他解释说，这些都是短暂的隐藏情绪的表达，执法人员和医科学生可以通过训练发现。约翰想知道这样的训练是否能使他成为一名优秀的测谎员。保罗回答说，测谎仪探测不到谎言，它们探测的是情绪。应该使用一整套分析行为的工具来揭示一个人是否隐藏了一种感觉。然而，如果有人在他们所做的事情上撒谎，而不是他们的感受呢?保罗提到这是一个需要注意的重要区别。

Following a short break, Paul points out the universality of human emotional expression. He then mentions that most people are terrible liars and lie catchers. Ken, John, and Paul explore this fact from an evolutionary perspective; humans evolved in small communities, where it was difficult to get away with anything. Now, even in a society with such little face-to-face interaction, Paul doesn’t think lying has become any easier. Next, Ken posits that the ability to read the face might be connected to a broader ability to understand people’s beliefs, but Paul insists that thoughts, unlike feelings, are private and have no signal. He humorously adds that you can shut your mouth but not your face.

In response to a wealth of audience questions, Paul comments on everything from Tourrete syndrome to Mona Lisa’s famous expression to the Jonathan Edwards scandal. He concludes by responding to a question about whether it is possible to infer information about someone’s character from their face. Although there might be accurate information towards this end, Paul states, it is yet to be documented.

• Roving Philosophical Report(Seek to 5:50): Caitlin Esch interviews researcher David Wilkins and actor Kay Kostopoulos, co-instructors of the Stanford class “Learning Facial Emotions: Art and Psychology.”
  
• 60-Second Philosopher(Seek to 47:59) : Ian Shoales comments on Future Attribute Screening Technology (FAST), a program for facial recognition that is being tested by the Department of Homeland Security. He humorously suggests that making use of Facebook’s “TMI” culture could be a viable alternative to expensive surveillance equipment.