## Definition **The Categorical Imperative** is Immanuel Kant's supreme principle of morality, articulated in the *Groundwork of the Metaphysics of Morals* (1785): an action is morally required if and only if the maxim on which it is performed can be universalised without contradiction, and it treats rational persons as ends in themselves rather than merely as instruments. Unlike a *hypothetical* imperative ("do X if you want Y"), the categorical imperative commands unconditionally — it binds every rational being regardless of their desires or circumstances. ## The First Formulation: Universal Law > "Act only according to that maxim by which you can at the same time will that it should become a universal law." Warburton renders this as: before doing something, ask yourself — *what if everyone did this?* If universalising the proposed maxim produces a logical contradiction or a world you could not rationally will to exist, the action is forbidden. Kant's own example: you need money and consider making a false promise to repay a loan. If everyone made false promises whenever convenient, the institution of promising would collapse — the maxim self-destructs when universalised. Therefore, false promising is impermissible regardless of the benefit it would bring in any particular case. ## The Second Formulation: Humanity as an End > "Act so that you treat humanity, whether in your own person or in that of another, always as an end and never as a means only." Rational beings have a dignity that places them beyond price. Using a person as a mere tool — deceiving, coercing, or instrumentalising them — violates this dignity even if the outcome is beneficial. Warburton identifies this formulation as Kant's most lasting contribution: the concept of human dignity and inviolable rights that underpins modern international human rights law. ## Duty Over Feeling Kant argued that the moral worth of an action derives entirely from the will's conformity with duty (*Pflicht*), not from the feelings or inclinations that accompany it. Giving money to a beggar because it warms your heart is not a morally worthy act; giving because it is your duty, even when you feel no inclination to do so, is. Warburton notes that this apparently cold position has a democratic implication: moral goodness is available to anyone capable of acting from duty, regardless of warmth of character or emotional sensitivity. ## The Limits: Inflexibility Warburton points to the theory's most notorious difficulty. Kant held that lying is always impermissible. Applied literally, this yields the conclusion that it would be wrong to lie to a murderer who asks where your friend is hiding. The categorical nature of the imperative — no exceptions, no trade-offs — clashes sharply with moral intuitions that most people consider compelling. This rigidity is precisely what Utilitarianism was designed to avoid. ## Relation to Rationalism The Categorical Imperative is an expression of Kant's broader rationalism in ethics: moral law is discovered by pure practical reason, not derived from experience, emotion, or divine command. Like mathematical truths, moral imperatives hold necessarily and universally. This places Kant in sharp contrast with empiricist and consequentialist traditions. ## Related - [[Empiricism vs Rationalism]] - [[Utilitarianism]] - [[Aristotelian Virtue Ethics]] ## Sources - [[A Little History of Philosophy (Warburton 2011)]]