Our topic this week is Cooperation and Conflict. Cooperation is found in many species of animals. Take dolphins, wolves, and chimpanzees. They’re all amazinglysuccessfulhunters. Why? Because they’re highlycooperativehunters. And there’s no doubt that human beings have taken the art of cooperation to levels that our animal friends can’t begin to match. Take money. Money makes possible the kind of co-operation and coordination required to make a sprawling economic system work. But it’s not just in the domain of the economy that humans cooperate. Politics, education, science---- all of them are domains in shaped by highly complex forms of cooperation. Cooperation is so pervasive among human beings that it doesn’t seem all that far-fetched to think that natural selection has specifically designed human beings to cooperate. At any rate, cooperation clearly has been and will be the key to our survival. Indeed, we need more of it than ever. 21^stcentury humans have to cooperate on a massive scale. Otherwise the earth might burn to a crisp.

Unfortunately, I’m not altogether optimistic that we’re going to pull that level of cooperation off. Humans cooperate, but they also fight. There is as much conflict among humans as cooperation --- or more. We construct complex, cooperative social realities like nations, only to have them engage in insanely destructive wars. We start out promising to love, honor, and obey, only to see many marriages devolve into contested divorces. At a minimum, that shows that it’s way too simple to say that humans are specifically designed for cooperation.

But that’s not really all that’s surprising, though, is it? Sometimes, cooperation is for suckers. To see why that’s so, consider an example adapted from David Hume.

Imagine two farmers -- Duncan and Ethan. Each of them has a field to plow. Each field is too large for one man to plow easily or quickly. Time is running out to get our fields plowed and our crops in. So Ducan makes Ethan an offer. He says to Ethan that he, Duncan, will help him, Ethan, plow Ethan’s field tomorrow, if Ethan will help him, Duncan, plow Duncan’s field today. Would Ethan accept the offer? Should he accept it, if his is rational?

答案吗?那得看情况。特别是，这取决于伊森能否确信邓肯在得到伊森的帮助后会坚持到底并帮助他。如果他能确定这一点，伊森就会接受邓肯的提议。

但伊森真的能确定邓肯会坚持到底吗?I mean, if I’m Duncan and I'm purely self-interested and not altruistic, then it won’t take long to dawn on me that helping Ethan, once I’ve already got my field plowed, isn’t going to domeany particular good. So why should I follow through? Why would I?

另一方面，如果我是伊桑，我提前就能看出邓肯只是另一个自私的小混蛋，那么我可能不会接受他的报价。也许我不应该接受他的提议。我要是这么做，肯定是个傻瓜。但那样的话，我们就都没人耕地了。那有什么好处呢?

So maybe the right thing to conclude is that Duncan reallyshouldn’tbe such a self-interested S-O-B after all. It’s not in his self-interest to be.

On the other hand, you could make a case that it’s not a matter of selfishness, it’s a matter of rationality. When you’re rational, you do what gives the greatest benefit for the least cost. Once Ethan has helped Duncan plow his field, Duncan should do a cost benefit analysis. Helping Ethan tomorrow is a cost – a pure cost. Duncan already got his field plowed, so there is no additional benefit in plowing Ethan’s field. So if Duncan is rational, he’ll say ``screw Ethan” once tomorrow comes.

Of course, by the same token, if Ethan is rational, and realizes that Duncan is rational, it seems that he won’t help Duncan plow his fieldtoday因为这样做对他来说纯粹是一种成本，明天不会有任何补偿效益。

But now we’re in something of a quandary. Rationality and cooperation are supposed to be hallmarks of being human. How do they fit together? How can they fit together, if cooperation always requiressomeoneto be an irrational sucker? That’s one of our main questions for this week.

休谟的农民困境实际上是囚徒困境的一个特例，在现代社会科学中占有重要地位。我们请四处游走的哲学记者凯特琳·埃施(Caitlin Esch)解释囚徒困境，并在现实生活中审视它——或者至少在真人秀中。之后我们请到了我们的嘉宾克里斯蒂娜·比奇耶里(Cristina Bicchieri)，她是宾夕法尼亚大学的社会思想和比较伦理学教授。She’s also the author ofThe社会语法:社会规范的性质和动力。

Photo byRandy FathonUnsplash