How to teach deontology

Why this matters

A student can say deontology means "follow the rules no matter what" and still not know which rule Kant means or why a lie fails his test. On a worksheet, "lying is against the rules" earns the point, and the answer never meets Kant's own argument. The student repeats the slogan in the essay, and the teacher has to wait for the unit test to find out who never got past it.

Deontology and Kant's categorical imperative

Deontology is duty-based ethics. The name comes from the Greek deon, duty, and a deontological theory says which choices are "morally required, forbidden, or permitted" (Stanford Encyclopedia of Philosophy, "Deontological Ethics"). Consequentialist theories such as utilitarianism judge a choice by the states of affairs it brings about, while the most familiar forms of deontology "hold that some choices cannot be justified by their effects" (same source).

Kant's categorical imperative is the best-known deontological test, and the Stanford Encyclopedia's entry on Kant's moral philosophy sets out its formulas. Two of them, as Kant wrote them in the Second Section of the Groundwork of the Metaphysics of Morals (Abbott's translation, Project Gutenberg):

• Universal law formula: "Act only on that maxim whereby thou canst at the same time will that it should become a universal law."
• Humanity formula: "So act as to treat humanity, whether in thine own person or in that of any other, in every case as an end withal, never as means only."

Kant tests the universal law formula on a lying promise. If everyone made promises they meant to break, "the promise itself would become impossible."

In the Flint activity, each student writes the maxim behind a white lie and tests it against a Groundwork excerpt attached to the activity. Unlike a worksheet, Sparky reads that student's answer and, when it is vague, quotes the sentence from Kant that the answer needs.

Sparky gets Elena to find Kant's reason in Kant's own words

Elena starts at "lying is against the rules" and ends up explaining why her excuse would stop working if everyone used it. Every student gets the same reading and white-lie case, and Sparky's replies depend on each student's answers.

Sparky uses Elena's debate clubSparky sends Elena back to the reading or her own maximA right answer gets the harder case

E

Elena

Interest: Debate clubStarting point: Thinks deontology means "follow the rules no matter what"

Elena

isnt it like following the rules no matter what? like you do your duty even if the outcome is bad

Sparky

The duty part is exactly right. Here's your first scenario: you want to skip a friend's party, so you text them "Sorry, I have a family thing," but it's not true. Can you write the maxim behind that lie as a general statement ("When I ..., I will ...") and say whether Kant would allow it, and why?

Elena

when i dont want to go to something, i will make up an excuse. kant wouldnt allow it bc lying is against the rules. but honestly its a white lie, nobody gets hurt so idk why it matters

Sparky

Good instinct to push back, that's the debate club in you! But "lying is against the rules" is a bit circular. Kant writes: "For supposing it to be a universal law that everyone when he thinks himself in a difficulty should be able to promise whatever he pleases, with the purpose of not keeping his promise, the promise itself would become impossible…" [1] Notice the lie only works because most people tell the truth. So what would happen to excuses like "I have a family thing" if everyone used your maxim?

Elena

ohh ok so if everyone made up a family thing whenever they didnt want to go, nobody would believe family things anymore. so the excuse would stop working. my lie only works bc everyone else is honest so im kind of making an exception for myself

Understanding check

That's exactly it. The lie is a free-rider on everyone else's honesty, which is precisely why it can't be universalized. Here's the harder case, a famous thought experiment. A stranger knocks on your door and asks where your friend is hiding, because they want to harm them. Kant's test seems to say you still can't lie. Using both formulas from your reading, can you test whether lying to the murderer passes or fails?

Elena

ok this one is harder. with the universal law one, if everyone lied to murderers then murderers wouldnt believe anyone so the lie wouldnt work, so i guess it fails?? but with the humanity one, the murderer is the one using my friend as a means, not me. and i dont think lying to him is treating him as just a tool, hes the one who gave up being honest with me. so idk kant might be wrong here

Sparky

Is the maxim "lie to murderers" really the one being universalized, or is it something broader like "lie to protect innocent people"? There is no single correct answer here. Kant himself said you must not lie, but many Kantians disagree with him on this exact case. So, debate-club style: which formula gives you the stronger defense of lying to the murderer, and what's the one-sentence reason you'd give to someone who challenged you?

Explained why her white lie fails Kant's test, then tested the murderer at the door with both formulas

Elena is an example student, and Sparky's replies are shortened.

What Flint did for Elena

• When Elena said "lying is against the rules", Sparky quoted the lying-promise sentence from the Kant reading attached to the activity, with a citation.
• Sparky asked what would happen to excuses if everyone used her maxim, and Elena worked out that her lie depends on everyone else's honesty.
• After that right answer, Sparky gave Elena the murderer at the door, then asked which maxim she was really universalizing.

A teacher can't do this by hand for 30 students, and Sparky does it in every student's chat.

The activity page shows who still says "it's against the rules"

While the class works, Needs attention shows the teacher which student is stuck and on which message. After three or more students submit, activity analytics lists what the class explained well, where students went wrong, and a follow-up to practice next.

Set up the activity for free

Open the deontology activity in Flint's public library, select Use activity to copy it into a free Flint account, and assign it to a class. The Kant excerpt is already attached to the activity's Guidelines for Sparky, so there is no setting to turn on. To use a different reading, attach it with the paper clip in Guidelines for Sparky (see which files Sparky can read). Pointing at a numbered citation in Sparky's reply shows the full passage and the file it came from.

For more ethics activities, see Flint for ethics.