Deontology
Kantian ethics · duty-based ethics · deontological ethics
Duty-based ethics: actions are right or wrong in themselves, regardless of consequences. Most associated with Kant.
In practice
A contractor is offered more to break an existing agreement than the agreement is worth. The deontological question is whether the promise binds regardless of the sums, and whether the other party is being used as a means.
The common mistake
Reading deontology as indifference to outcomes. A deontologist cares what happens; the claim is that consequences do not by themselves convert a wrong act into a right one.
Deontology holds that some actions are right or wrong in themselves, whatever follows from them. The name comes from the Greek deon, meaning duty. A deontologist can agree that lying will produce a better outcome in a particular case and still hold that you must not lie.
Kant's version
Immanuel Kant gave the position its most demanding form in the Groundwork of the Metaphysics of Morals (1785). His test, the categorical imperative, asks whether the principle behind your action could be willed as a universal law. A promise you intend to break fails immediately: if everyone made promises that way, the practice of promising would collapse, and the lie would have nothing left to exploit.
Kant gave a second formulation that is easier to hold in mind. Treat humanity, in yourself and in others, always as an end and never merely as a means. A person used purely as an instrument has been removed from the moral community while still standing in front of you.
What the theory buys, and what it costs
The appeal is protection. Because rights do not depend on a calculation, they cannot be traded away by a sufficiently large benefit to someone else. A utilitarian has to explain why the numbers do not license the sacrifice of one person for many; a deontologist rules it out from the start.
The cost shows up when duties collide. If you must never lie and must protect the innocent, the murderer at the door forces a choice the theory does not obviously make for you. Later deontologists answered by ranking duties or by allowing that some are defeasible, which softens the rigidity at the price of some of the original clarity.
Where it sits
Deontology is one of the three families of ethics, beside virtue ethics and utilitarianism. It descends in part from natural law, which also locates rightness in the act rather than the outcome, though natural law grounds it in human nature and Kant grounds it in reason alone.
Concept web
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What is deontology in simple terms?
Deontology is the view that actions are right or wrong in themselves, independent of their consequences. Certain duties — keep promises, tell the truth, respect persons — hold even when breaking them would produce a better result.
What is the difference between deontology and utilitarianism?
Deontology judges the act against a duty or rule. Utilitarianism judges the act by its consequences. The clearest split appears when harming one person would benefit many, which utilitarianism may permit and deontology generally forbids.
What is the categorical imperative?
Kant's test for a moral duty. Act only on a principle you could will to become a universal law, and treat humanity always as an end and never merely as a means. Principles that self-destruct when universalised fail the test.