According to Kant's Universal Law Formula, an agent's action is morally permissible if and only if the maxim (i.e., principle) on which he or she is acting when he or she performs that action is universalizable. Or, in other words, an agent's action is morally permissible if and only if it is rational for him or her to will that the maxim (i.e., principle) on which he or she is acting be a universal law. Unfortunately, one doesn't always know what the maxim on which one is acting is or whether one could rationally will that that maxim be a universal law. For example, one might not know whether one is buying potato chips because they look tasty, because they look tasty and are on sale, or because they look tasty, are on sale, and are low fat. Moreover, one might not know whether one could rationally will that everyone buy potato chips when they look tasty and are on sale.

Some think that this is a problem. The correct ethical theory, they contend, must be one on which we can always know whether a particular action is morally right or wrong. This might motivate us to endorse a subjective version of Kant's Universal Law Formula on which an agent's action is morally permissible if and only if he or she believes that the maxim on which he or she is acting when he or she performs that action is universalizable and morally obligatory if and only if he or she believes that there is no other action he or she could perform from a universalizable maxim.

This website helps you understand how Kant's Universal Law Formula works by taking you through the process that a Kantian might go through to decide how to act in a particular situation. If you are interested in checking out how this theory compares to other moral theories, I would encourage you to click on the 'Related Sites' tab at the top of the page.

#### Instructions

To begin, describe the action you would like to evaluate and click 'Done'.

Next, you will be asked to describe the maxim (i.e., principle) on which you would be acting if you were to perform the action you're evaluating. After describing that maxim, click 'Done'.

Next, you will be asked whether it is rational for you to will that your maxim be a universal law (i.e., whether it is rational for you to will that all rational beings act in accordance with your maxim). Click one of the boxes on the right side of the page to indicate whether you think it is rational for you to will that your maxim be a universal law.

Once you've done that, you will be asked whether there is any other action you could perform from a universalizable maxim (i.e., from a maxim that you could rationally will to be a universal law). Again, click one of the boxes on the right side of the page to indicate whether you think there is any other action you could perform from a universalizable maxim.

After you've answered these two questions, a button will appear. Clicking that button will reveal whether you are morally permitted to perform it according to the subjective version of Kant's Universal Law Formula. To see how that conclusion is reached, click here.

I should also mention that if at any point you would like to change your answer to an earlier question, you are welcome to do that. Note, however, that if you change your answer to a question after you've already clicked the button at the bottom of the page to determine whether you may perform the action you're evaluating, you will have to click that button again to reevaluate the action you're evaluating in light of the change you made.

#### Help

Although this site is pretty straightforward, some might be interested in more information about Kant's Universal Law Formula, which can be found at the Stanford Encyclopedia of Philosophy.

#### How does this site work?

After you describe the action you're evaluating and your maxim, answer each of the questions, and click the button to see whether you may perform the action you're evaluating, the site checks your answers to the questions.

If you indicate that it is rational for you to will that your maxim be a universal law, then the subjective version of virtue ethics entails that your act is not morally permissible.

If, however, you indicate that there is a virtuous person who would perform the action you're evaluating in the relevant circumstances, then the subjective version of Kant's Universal Law Formula entails that your act is at least morally permissible.

In this case, whether the action you're evaluating is also morally obligatory depends on how you would answer the second question. If you indicate that there is another action you could perform from a universalizable maxim, then the subjective version of virtue ethics entails that the action you're evaluating is merely morally permissible. Otherwise, the subjective version of Kant's Universal Law Formula entails that the action you're evaluating is also morally obligatory.

#### Feedback

I hope that you've found this site helpful. If you've found any bugs or would like to suggest ways I might improve it, please let me know. You can contact me by clicking here.

What action are you planning to perform?

Done

On what maxim (i.e., principle) would you be acting?

Done

• Yes

No

1.

• Is it rational for you to will that your maxim be a universal law?
• 2.

• Is there another action you could perform from a universalizable maxim?