It seems like two reasonable, intelligent people who have access to the same evidence should come to the same conclusion. So why is it that this is so often not the case, and that people are often confident in entirely opposite conclusions? John and Ken start off the show by honing in on what they aren’t going to discuss. John and Ken have opposite opinions on the taste of lima beans, for example, but this doesn’t constitute a real disagreement because there is no incompatibility between one person liking lima beans and another person despising them. Rather, disagreement of the relevant kind concerns factual matters. John wonders if there isn’t some inevitable amount of arrogance in belief formation; he has no choice but to develop beliefs based on his own evidence and his own reasoning after all. Ken says that others’ beliefs, and the fact that there is disagreement in the first place, should give you further evidence about the question at hand.

Ken and John invite Jennifer Lackey, Professor of Philosophy at Northwestern University, to the conversation. Jennifer starts by saying that people are inherently fallible at tracking truth, so disagreement is useful because it encourages individuals to re-examine and re-inform their beliefs. Next, Ken asks what should be done in cases of disagreement, and Jennifer responds by remarking that it’s dependent on the specific case.

对话转向讨论谁可以被称为“知识同伴”，即在推理能力和获取证据方面与另一个人相似的人。詹妮弗说，判断一个人是否有这种能力的标准之一，就是要有发现真相的动机。然而，一个打电话的人指出，即使某人不是你的认知同行，如果结果影响到你，你可能仍然无法否定他们的信念。肯想知道，分配认知同伴的想法是否有黑暗的一面。难道你不能简单地把其他人排除在认知同侪之外，从而隔离你的信仰吗?詹妮弗同意;例如，一个信教的人可能不会把一个非信教的人看作是同一证据的知情者，因此也就没有资格作为一个知识的同侪来考虑。

In the latter portion of the show, the focus shifts to political and religious disagreements. Jennifer also teases apart the difference between a practical belief and a epistemically rational one. She concludes by saying that by using disagreement as an opportunity to reconsider and adjust accordingly, we can avoid being both spineless and dogmatic in our beliefs.

• Roving Philosophical Reporter(Seek to 5:44): Listeners are offered a glimpse into the lives of Joe and Carol McLaughlin, a married couple from San Francisco with fundamentally different political beliefs. They describe the strategies they employ to deal peacefully with their differences.
• 60-Second Philosopher(Seek to 48:41): Ian Shoales shares with listeners his personal opinions on a range of topics, from zombie movies to Vietnam, and the disagreements with others that these have sparked. He concludes by scorning the idea of “agreeing to disagree” as nothing more than a passive-aggressive form of simple disagreement.