Our topic today: Faces, Feelings, and Lies. And, in particular, how can we know what a person is feeling by looking at their face, and in particular can we know if they are lying? There is clearly both a psychological side to this and an epistemological side. Our guest is famous for his work on the psychological side, with a positive result: we can know what a person is feeling, and whether they are lying; at least the information is often there in the face. But it’s not always so easy.

Ken and I will also be interested too in the epistemological side; what is the relation between the evidence we can see and the conclusions we draw? We can start with the conclusions. To what extent are feelings and emotioins, including the sincerety with which one says something,hidden?

By feelings we mean not only the inner experience we have in certain situations. But these feelings --- or better, `emotions ‘ seem to also have a cognitive element. If we're angry, we're angry about something. If you carelessly spill coffee on me, I would have a feeling of anger. But it would be angeratyou, for spilling the coffee, or for being careless. The emotion seems to be a complex, involving a feeling and a belief that gives rise to it and sustains it. Sometimes we feel anger, but don’t know what we're angry about. That’s not terribly uncommon, but it is odd. We're perplexed until we figure out what we're angry about.

Indeed, David Hume, the philosopher, thought the very same inner feeling could be connected with different emotions, where the cognitive factor was the differentiating element. When Ken finishes his book on norms, I’m sure he’ll be proud of it. The cause of the pride will be the perceived high quality of the book. The object of pride will be Ken himself. The feeling is pleasure. Now consider the esteem Ken feels for me. The cause is my intelligence and wit. I am the object. But the feeling is basically the same, pleasure.

What about the anger I had for you, when you carelessly spilled coffee on me? Well, the cause is my spilling coffee, the object is me, and the feeling is displeasure. If you spilled the coffee on yourself, that would be the cause, the object would be you, i.e., self. The feeling would also be displeasure, and that combination of things we call humiliation, not anger.

Hume is no doubt not the last word on emotions. I think our guest, Paul Ekman, will tell us that modern techniques of experimentation make it pretty clear that the same feelings are not involved in different emotions, in the way Hume thought. Still, cause, object, and feeling seems like a useful framework. Maybe it explains why it can be hard to tell what emotion another person is having. You have to knowwhattheir feeling is,whoit's directed towards --- the object --- andwhy, the cause.

At any rate, if inner feelings are in part definitive of a person’s emotions, that explains why itseems要弄清楚另一个人的情绪是很难的;也许不可能知道一个人是对的，因为人们有能力假装。但事实上，这并没有那么难，也不是不可能。这就是脸的作用。事实上，我们非常善于察觉别人的情绪，有时甚至比我们自己的还要好，这与脸有关。演员通过学习正确的面部表情来学习表达各种各样的情绪。今天，我们的嘉宾是世界上最重要的面部和情感权威之一，旧金山的保罗·埃克曼。他发现，脸部短暂的变化，也就是他所说的“微表情”，是预测一个人情绪的可靠向导，尤其是在撒谎时。