explain and evaluate Kantian deontology, including the categorical imperative, the formula of universal law and the formula of humanity

What this dot point is asking

QCAA wants you to explain and evaluate the leading deontological (duty-based) ethics: that of Immanuel Kant. Unlike utilitarianism, Kant holds that rightness depends on duty and the form of the maxim, not consequences. You need the good will, the categorical imperative and its main formulations, plus the standard objections. This contrasts directly with utilitarianism in IA and exam essays.

The answer

The good will and duty

Kant, in the Groundwork of the Metaphysics of Morals (1785), opens by claiming that the only thing good without qualification is a good will. Intelligence, courage and even happiness can be bad if used by a bad will. Moral worth lies not in results but in acting from duty, for the sake of the moral law itself, not from inclination or self-interest. An action has moral worth when done because it is right, not merely because it accords with what is right.

Categorical versus hypothetical imperatives

A hypothetical imperative commands a means to an end you happen to want ("if you want to be trusted, keep promises"). A categorical imperative commands unconditionally, binding all rational agents regardless of their desires ("keep promises"). Morality, Kant argues, must be categorical, because a duty that held only if you wanted something would not be a genuine moral obligation.

The formula of universal law

Kant's first formulation: act only on that maxim (the principle of your action) that you could will to become a universal law. To test an action, universalise its maxim and ask whether it could hold for everyone without contradiction. A lying promise fails: if everyone made lying promises, the practice of promising would collapse, so the maxim cannot be consistently universalised. The will would contradict itself in willing both to make a promise and to destroy promising.

The formula of humanity

Kant's second formulation: act so as to treat humanity, whether in yourself or another, always as an end and never merely as a means. Persons are rational agents with dignity, not mere tools. Deceiving or coercing someone uses them merely as a means, because they cannot rationally consent to the deception. This formula grounds respect for persons and underpins much of modern human-rights thinking.

Strengths

• It captures the intuition that some acts (torturing the innocent, lying) are wrong in themselves, not merely when they produce bad outcomes.
• It grounds the equal dignity of persons and protects individuals against being sacrificed for the greater good, answering a key utilitarian worry.
• It ties morality to reason and consistency, giving an objective test independent of desire.

Major objections

• Conflicting duties: if I must never lie and must protect the innocent, what do I do when a murderer asks where my friend is hiding? Kant notoriously held you may not lie even then, which strikes many as monstrous.
• Rigidity / absolutism: exceptionless rules ignore morally relevant consequences.
• Empty formalism (Hegel's charge): the universal-law test may permit too much or too little, since maxims can be described to pass or fail at will.
• Ignoring consequences: focusing only on the maxim seems to disregard the actual harm or good an action does.

Try this

Q1. Distinguish a categorical from a hypothetical imperative. [3 marks]

• Cue. Hypothetical commands a means to a desired end; categorical commands unconditionally for all rational agents.

Q2. Apply the formula of universal law to a lying promise. [4 marks]

• Cue. Universalised, lying promises destroy the practice of promising, so the maxim cannot be willed without contradiction.

Q3. State one objection to Kantian ethics. [2 marks]

• Cue. Conflicting absolute duties, for example the duty not to lie clashing with protecting an innocent person.