I don't know if you've noticed this, but all of our discussions about ethics so far have had one thing in common: God.

Divine command theory, for example, argues that what's good and what's not are determined by a deity, whether that's the God of Abraham, or a panoply of gods who come up with ethical rules by committee.

And the theory of natural law as advanced by Thomas Aquinas says that morality comes from us but only because we were made by God who preloaded us with moral sensibilities.

But many other thinkers have argued that humanity's moral code doesn't come from some supernatural force.

18th century German philosopher Immanuel Kant, for one, thought religion and morality were a terrible pairing, and if anything, the two should be kept apart.

Instead, Kant argued, in order to determine what's right, you have to use reason. And a sense of consideration for other people. And, at least the way I'm teaching it today, chom-choms.

Kant took morality pretty seriously and he thought we should, too: all of us regardless of our religious beliefs or lack thereof.

Because he knew that if we look to religion for our morality, we’re not all going to get the same answer.

But he thought morality was a constant, in an almost mathematical sense.

Two plus two equals four, whether you're a Christian, Buddhist, or atheist. And for Kant, the same went for moral truths.

But he made a distinction between the things we ought to do morally and the things we ought to do for other, non-moral reasons.

He pointed out that, most of the time, whether or not we ought to do something isn't really a moral choice – instead, it's just contingent on our desires.   Like, if your desire is to get money, then you ought to get a job. If your desire is get an A in class, then you ought to study.

Kant called these if-then statements, hypothetical imperatives. They're commands that you should follow if you want something. But hypothetical imperatives are about prudence rather than morality.

So, if you don't want money, you can always choose not to work. And if you don't care about getting a good grade, studying becomes totally optional. It'd be a terrible option, in my opinion as an educator, but still, optional.

But Kant viewed morality not in terms of hypothetical imperatives, but through what he called categorical imperatives. These are commands you must follow, regardless of your desires. Categorical imperatives are our moral obligations and Kant believed that they're derived from pure reason. He said, it didn't matter whether you want to be moral or not – the moral law is binding on all of us. And he said, you don't need religion to determine what that law is, because what's right and wrong is totally knowable just by using your intellect.

OK, so how do you figure out what's moral?

Kant said the categorical imperative can be understood in terms of various formulations: basically, different ways of phrasing or looking at the same essential idea.

And he came up with four formulations of the categorical imperative. Let me tell you about the two most popular ones.

The first formulation of the categorical imperative is often known as the universalizability principle. And Kant phrased it this way: "Act only according to that maxim which you can at the same time will that it should become a universal law without contradiction."

Okay, Kant: Pretty wordy guy. So, let's unpack what he was saying. A maxim is just a rule or principle of action. And a universal law is something that must always be done in similar situations.

So, as a Kantian, before I act, I would ask myself, what's the maxim of my action? In other words, what's the general rule that stands behind the particular action I'm considering?

Let's say you forgot your wallet in your dorm this morning. You don't have time to go get it between classes, and you're really hungry. You notice that the student working the snack kiosk in the union is engrossed in a conversation and you could easily snag a banana and be on your way. Sorry. Chom-chom. I mean: chom-chom. You could easily swipe that chom-chom and be on your way.

Is it OK, morally, for you to do this? Well, the particular action you're considering – taking a chom-chom from a merchant without paying for it – is stealing.

And, if you approve the maxim of stealing – which you're doing, whether you admit it or not – then what you're actually doing is universalizing that action – you're saying that everyone should always steal. If you should be able to do it, then everyone should be able to do it.

The thing is, this leads to a contradiction. And remember, Kant's wording specifically says that moral actions cannot bring about contradictions.

The contradiction here is, no one would say that everyone should steal all the time. Because, if everyone should always steal, then you should steal the chom-chom and then I should steal it back from you, and then you should steal it back from me, and it would never end and no one would ever get to eat any chom choms. Therefore, stealing isn't universalizable.

So, what Kant’s really saying is that it's not fair to make exceptions for yourself. You don't really think stealing is OK, and by imagining what it would be like to universalize it, that becomes clear.

Now, Kant's view that moral rules apply to everyone equally sounds nice and fair, but it can sometimes lead to some pretty counterintuitive results. To see how this formulation can go awry, let's visit the Thought Bubble for some Flash Philosophy.

Let's say, one morning, Elvira and Tony are having breakfast. Then a stranger comes to the door and asks where Tony is so he can kill him. Obviously, Elvira's impulse is to lie and say that "Tony isn't around right now" in order to protect him from this would-be murderer. But Kant says, she can't lie ... not ever, not even to save Tony's life.

Here's his reasoning: Suppose she's at the front door, talking to the stranger. At the time, she thinks Tony's in the kitchen where she left him. But it turns out he was curious about the caller. So, he followed her into the living room and heard the stranger make his threats. Fearing for his life, Tony slipped out the back door.

Meanwhile Elvira, in her desire to save him, tells the stranger that Tony isn't there, even though she thinks he is. Based on her lie, the stranger leaves and runs into Tony as he rounds the corner heading away from the house, and kills him.

Had she told the truth, the stranger might have headed into the kitchen looking for Tony, which would have given Tony time to escape. But she didn't.

Now, by Kant's reasoning, Elvira is responsible for Tony's death, because her lie caused it. Had she told the truth, only the murderer would have been responsible for any deaths that might have occurred.

Now, she could have refused to answer the stranger altogether, or tried to talk him out of it. But the one thing she is never permitted to do is violate the moral law, even if others are doing so, even for a really good cause. Poor Tony. Very sad. But thanks, Thought Bubble!

So, the first formulation of the categorical imperative is about the universality of our actions.

But the second formulation focuses on how we should treat other people. And it goes this way: "Act so that you treat humanity, whether in your own person or in that of another, always as an end, and never as a mere means."

Again, we have to define some terms here to figure out what this is all about. To use something as a "mere means" is to use it only for your own benefit, with no thought to the interests or benefit of the thing you're using.

Now, we use things as mere means all the time. I use this mug to hold my coffee. And if it were to stop benefiting me - like if it got a crack in it and started leaking - I wouldn't use it anymore.

It's perfectly fine to use "things" as mere means, but not humans. This is because we are what Kant called ends-in-ourselves.

We're not mere objects that exist to be used by others. We're our own ends. We're rational and autonomous. We have the ability to set our own goals, and work toward them. Coffee mugs exist for coffee drinkers. Humans exist for themselves.

So, to treat someone as an "end-in-herself" means to recognize the humanity of the person you're encountering, to realize that she has goals, values, and interests of her own, and you must, morally, keep that in mind in your encounters with her.

Now, Kant pointed out that we do use people, all the time, and that's okay. Because most of time, we use other people as a means for something, but not as a mere means. We still recognize their humanity when we use them and they agree to being used.

So, for example, you are using me right now to get information about Kantian ethics. I am using Nick and Nicole to help me get that information to you. Kant said that you and I, and Nick and Nicole – we all we deserve to not be used as mere means, because of our autonomy.

Unlike other things in the world, we're self-governed. We're able to set our own ends, to make our own free decisions based on our rational wills. We can set goals for ourselves and take steps to realize those goals.

This imbues us with an absolute moral worth, Kant said, which means that we shouldn't be manipulated, or manipulate other autonomous agents for our own benefit.

And this means that things like lying and deception are never okay. Because if I'm being deceived, I can't make an autonomous decision about how to act, because my decision is based on false information. 

For instance, I might agree to loan you money so you can buy books for school, but I wouldn't agree to loan you money so that you can get a new Xbox. I'm sorry, but no.

So when you lie to me about what you're gonna be doing with the money you're asking for, you rob me of my ability to autonomously decide to help you.

You've treated me as a mere means to accomplish your goals, with no thought to my own goals and interests. And that's a violation of Kant’s second categorical imperative.

So, Kant argued that proper, rational application of the categorical imperative will lead us to moral truth that is fixed and applicable to all moral agents. No God required.

Of course, not everyone agreed with him. So, next time we're going to check out a theory that is in many ways the antithesis of Kantianism, utilitarianism.

Today we learned about Kant's ethics. We talked about hypothetical and categorical imperatives, the universalizability principle, autonomy, and what it means to treat people as ends-in-themselves, rather than as mere means.

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