你能通过推理成为一个好人吗?还是你的感觉能更好地引导你做正确的事?道德应该对每个人都一样吗?This week we’re thinking about German enlightenment philosopherImmanuel Kant and his view of a universal morality based on reason．

Kant accepted that feelings are important alongside reason—that it’s good to cultivate cheerfulness, and bad to laugh at people in a mean-spirited way. But he thought that our emotions could easily lead us astray, and that only reason can be the final arbiter. Feelings like empathy can motivate you to do good, but they can also lead you astray: what if your empathy for a thief motivates you to help them break into your neighbor’s house and steal all your neighbor’s things?

And you should be willing to do the right thing even when you don’t have warm, fuzzy feelings: it would be wrong to break a promise to visit your friend in the hospital just because you didn’t happen to feel like going.

You might object: can’t your reason get it wrong and your emotions get right? Think of Mark Twain’s protagonist Huck in his novelHuckleberry Finn．哈克的朋友吉姆是一个逃跑的奴隶，哈克必须决定是否把他交给当局。哈克的大脑告诉我们答案是肯定的:他有责任遵守法律，把逃跑的奴隶交还给他们的主人。但他的心说不。在这种情况下，哈克的大脑显然是错的。

Kant could reply that Huck’s brain is wrong because he’s failed to reason properly: reason would tell him that slavery is wrong, because it’s using another person as a means to an end. (Unfortunately, Kant himself didn’t have a great track record on opposing slavery, andhe wrote a lot of explicitly sexist and racist things．当代康德学派或康德哲学的追随者会说，奴隶制与理性相悖，而康德只是在运用自己的思想方面做得很糟糕。)

Not only does Kant think that reason is our best guide to morality, he also thinks it gives us acategorical imperative．That’s an impressive piece of jargon, but it basically means that reason commands us to do certain things (that’s theimperativepart), and that unlike other commands, there’s no way to exempt yourself (that’s thecategoricalpart). Etiquette tells you that if you want to set a formal table, you should place the salad fork to the left of the dinner fork—that’s an imperative of etiquette. But if you don’t want to set a formal table, then you have no reason to follow that command—it’s not a categorical imperative. Morality tells you not to murder people—that’s also an imperative. And unlike in the etiquette case, you can't get out of that just by not caring about morality—it's a categorical imperative.

But what does the categorical imperative actuallysay? What does reason tell you todo? For Kant, it boils down to one command: you should never treat anyone as a mere means to an end. This means that you can’t hurt or manipulate others to get what you want; you have to take their feelings into account. That’s why it’s wrong to lie to others to get what you want; it’s a way of using them.

康德还有其他一些方式来表达同样的命令。(学者们还不清楚它们是否真的等同于同一件事，但康德坚持认为它们是一样的。)他建议，另一种理解绝对命令的方式是考虑你行动的原因，并问自己这是否是每个人都赖以生存的好理由。例如，假设你在考虑是否应该撒谎来给某人留下深刻印象。你应该问问自己:如果每个人都为了给别人留下好印象而撒谎怎么办?如果那样的话，我们就不能信任彼此了，所以你撒谎的企图就没有意义了:没有人会相信你。康德说，既然你不可能让自己生活在一个每个人都通过撒谎来取悦别人的世界里，理性(因此也包括道德)告诉你不要为了取悦别人而撒谎。

Applying Kant’s theory is tricky. Kant had a lot to say about a range of applied topics, from lying (always wrong,even if you’re trying to save someone else’s life) to suicide (also always wrong) to friendship (a complicated balance of intimacy and respect) to what to do at dinner parties (best to avoid competitive games and mean-spirited gossip). Contemporary philosophers have applied Kant’s ideas about ethics to a wide range of topics that he didn’t address, fromfeminismtouniversal health care．

I still have some doubts about Kant’s way of doing things. Does his distinction between reason and emotion really hold up to scrutiny? If he had trouble applying his own theory, is it really a useful moral guide? Should I even be looking for universal principles to guide my actions, rather than rules of thumb that work well enough in my cultural context?

On this week’s show, Josh and I welcome back ethicist Karen Stohr, author of a new book,Choosing Freedom: A Kantian Guide to Life．我很高兴听到她对我的一些重大问题的回答，并了解康德的哲学在今天的道德问题上告诉我们什么。