What would Kant do when two categorical imperatives conflict? Could he ever justify lying?

Answer 1

What a philosophically provocative question!

Short answer: For Kant, two categorical imperatives cannot truly conflict, because the moral law is a single system of duties grounded in pure practical reason. What looks like a conflict is usually (1) a misunderstanding of the duties involved, or (2) a clash between a perfect duty (strict, exceptionless) and an imperfect duty (wide, allowing choice in how it’s fulfilled). In cases of apparent conflict, Kant says perfect duties always take priority.

LONG ANSWER

Why categorical imperatives cannot conflict:

Kant argues that contradictions within the moral law are impossible: “Duty and obligation in general are concepts that express the objective practical necessity of certain actions” (Groundwork, Ak. 4:413). If reason commanded two actions that could not both be done, reason would contradict itself—an impossibility for Kant.

So when two duties seem to clash, the solution is to look more carefully at:

1. Which duties are perfect (strict, exceptionless), and
2. Which duties are imperfect (requiring promotion of an end, but with flexibility).

A perfect duty always overrides an imperfect one.

Could Kant justify lying?

Famously No! Kant insists that the duty not to lie is a perfect duty. Perfect duties admit of no exceptions—not even extreme ones. In his 1797 essay On a Supposed Right to Lie, he argues that once you allow exceptions “based on expected consequences,” you abandon the very principle that makes promising and speaking intelligible in the first place.

For Kant:

1. Telling the truth = a strict duty grounded in respect for rational agency.
2. Preventing harm = an imperfect duty that depends on circumstances.

Since perfect duties override imperfect ones, lying is never morally permissible.

But what about conflicts—like the murderer at the door?

Kant’s answer is subtle and often misunderstood. He does not say you must disclose information. He only says you must not lie. You may:

1. remain silent,
2. refuse to answer,
3. change the subject,
4. physically intervene to protect someone,
5. close the door and leave.

But you cannot “make yourself an exception” by fabricating a statement, because that undermines the universal conditions that make communication possible.

So what would Kant do when duties seem to conflict?

He would:

1. Re-examine the maxims to determine which duty is perfect.
2. Recognize that imperfect duties always allow alternative ways to fulfill them.
3. Conclude that no true conflict exists within the categorical imperative itself.

Bottom line:

For Kant, moral conflicts arise from our interpretation, not from practical reason itself. And because the duty not to lie is a perfect duty, Kant would never justify lying—even when other moral pressures are strong. The moral law, for him, must be exceptionlessly universal if it is to bind all rational beings.