Kant’s Categorical Imperative

The central ethical concept in the deontological moral philosophy of Immanuel Kant. Unlike hypothetical imperatives (which depend on a desire), the categorical imperative is an absolute, unconditional requirement.

The Four Formulations

Kant presented the Categorical Imperative in several ways, which he believed to be different expressions of the same principle.

1. The Formula of Universal Law

“Act only according to that maxim whereby you can at the same time will that it should become a universal law.”

  • The Test: Before you act, ask: “Would I want everyone else to act this way too?” If universalizing your action creates a contradiction (e.g., everyone lying makes lying impossible), the action is immoral.

2. The Formula of Humanity (End in Itself)

“Act in such a way that you always treat humanity… never simply as a means, but always at the same time as an end.”

  • The Principle: Never use people as mere tools or objects to get what you want. Every human has inherent dignity and worth and must be respected as an autonomous agent.

3. The Formula of Autonomy

“So act that your will can regard itself at the same time as making universal law through its maxims.”

  • Identity: We are not just subjects to the moral law; we are its authors. Morality is not imposed from outside but arises from our own rational nature (self-legislation).

4. The Formula of the Kingdom of Ends

“So act as if you were through your maxims a law-making member in the universal kingdom of ends.”

  • Vision: Act as if your actions were the laws for an ideal community where everyone treats everyone else as an “end” rather than a “means.”

See also: Golden Rule