3 Tutorials that teach Applying Kantian Deontology
Take your pick:
Applying Kantian Deontology

Applying Kantian Deontology

Author: John Lumsden

Given a situation, apply Kantian deontology

See More
Introduction to Psychology

Analyze this:
Our Intro to Psych Course is only $329.

Sophia college courses cost up to 80% less than traditional courses*. Start a free trial now.


In this tutorial we will look at how Kantian deontology fits with our everyday ideas about right and wrong, before seeing how this ethical theory responds to certain issues in applied ethics. Our discussion will break down like this:
  1. Review of Kantian Deontology
  2. Agreement with Everyday Morality
  3. Disagreement with Everyday Morality
  4. Some Uncertain Cases
  5. Topics in Applied Ethics

1. Review of Kantian Deontology

To begin with, recall that Kantian deontology is a form of deontology that places absolute moral value in the agent's intent. The way you figure out if an intent is good or not is by seeing if it follows the categorical imperative.

Recall that the categorical imperative is that moral demand or law that’s binding on everyone, no matter who you are or what circumstances you find yourself in.

Kant knew that it’s difficult to see what the categorical imperative is telling us to do. To make it easier, he gave different formulations of it. These formulations determine the kind of principles, what Kant called maxims, that should guide your action. One of them is the formulation of universal law. You can test your maxim using this formulation like this:


One of Kant’s other formulations gets us to think about our humanity. He argues that this is more valuable than anything else. For this reason, we should only use it for some other purpose if we can respect its value at the same time. This is called the formulation of humanity. You can test your maxim using this formulation like this:


2. Agreement with Everyday Morality

Sometimes our everyday understanding of what is right and wrong agrees with what the categorical imperative demands. For instance, most of us think killing someone merely for our own gain is wrong. Depriving someone of their humanity just so you can get what you want fails to meet the categorical imperative. That’s because this would use humanity as a mere means.

Another example is our belief that we should return things to their owners. To see why the Kantian deontologist agrees with this, let’s evaluate a maxim that’s the opposite of this everyday moral belief.

“When people lend me things I will keep them for myself.”

If everyone held this maxim, then no one would lend things anymore because they know they would never get them back. By making this maxim universal it contradicts itself. That’s because the intention of the maxim was to get stuff for free by never returning things. But no one would lend things anymore, thus undermining the intention.

By testing this maxim with the formulation of universal law, you can see that the Kantian deontologist would say we should return things to their owners.

3. Disagreement with Everyday Morality

There are other cases, however, where our everyday understanding of what is right and wrong doesn’t agree with what the categorical imperative demands. For instance, most of us don’t think it’s morally impermissible to be lazy. You might dislike laziness, but you probably wouldn’t prohibit it.

For Kant, you are going against the categorical imperative if you’re lazy. That’s because you not only have a duty to preserve humanity, but also to further humanity.

If you just watch TV all day, then you aren’t using and improving your rational capacities.

Another example is our belief that lying is sometimes justified. Kant thinks it’s never justified because you devalue humanity when you use deception to achieve some other goal.


Imagine a friend asked for your honest opinion about their latest art work. You don’t like it, but you don’t want to hurt their feelings. So, instead of telling them the truth, you lie and say you think it’s great.

This goes against the categorical imperative because you aimed to save someone’s feelings, rather than respect their human capacities. If you gave them honest feedback, they would have the opportunity to reflect on it and grow as a rational agent.

Some people might put their friend’s personal development above their friend’s comfort. But the point is that most wouldn’t think you’re obliged to do so. And the Kantian deontologist does think there is such an obligation.

4. Some Uncertain Cases

Sometimes it’s not clear whether or not our everyday moral views fit with Kantian deontology. This can be because the categorical imperative can seem to give two different answers to what it is we ought to be doing.

For instance, sometimes it seems that being a good person (i.e. having a good will) is the only goal that all people can aim for under any circumstances. But Kant also allows happiness to be a moral goal for all people. This seems a bit confusing. After all, doesn’t Kant say that happiness can be bad if it’s a bad person that’s happy? Only the good will is always good.

But Kant gets round this by saying that securing happiness can help us to be moral.

If you're unhappy, you’re more likely to follow your desires rather than doing the right thing. For instance, if you’re in a bad mood when someone approaches you asking to give to charity, you’re might decide to cheer yourself up by spending your money on a treat instead of giving it away.

Another instance of an unclear result is found when some maxims meet the standard of one formulation of the categorical imperative, but not the other.


Imagine you want to be the only student in your class so that you can get all the teacher’s attention and therefore improve quicker. So you decide to get to class early every day, before everyone else gets there.

You haven’t undermined humanity in any way, so it should be fine according to the Formulation of Humanity. But it would fail the universalizability test. That’s because, if everyone did the same as you, you would no longer get the teacher’s attention, thus contradicting the intention of your maxim.

5. Topics in Applied Ethics

Philosophers working in ethics often try to apply ethical theories to specific situations. Let’s consider how a Kantian deontologist might apply their ethics to the following issues.

  1. the moral permissibility of suicide
  2. the moral permissibility of abortion
  3. the moral permissibility of torture

Here are the positions that Kantian deontologists take on these issues.

Kantian Deontology and Applied Ethics
Suicide Killing yourself to end suffering is impermissible because your'e getting rid of your humanity just to ease your pain.
Abortion If a fetus is classed as a person, then it's impermissible. If a fetus isn't classed as a person, then it's permissible.
Torture Torturing someone until they talk is impermissible because your'e using them as a means to your ends.

If you disagree with these ethical judgments, then you may not think Kantian deontology is the best ethical framework for judging which actions are right and wrong.

We started this tutorial with a review of Kantian deontology, focusing on two of the formulations of the categorical imperative. Then we looked at the ways Kantian deontology can be in agreement with everyday morality, and how it can be in disagreement with everyday morality. We saw how using the categorical imperative makes sense in some situations, but seemed too strict in others.

Then we looked at some uncertain cases where it was not clear whether there was agreement with our everyday morality. Finally, some topics in applied ethics were considered from the perspective of Kantian deontology.