Retributivism holds that punishment is justified because the offender deserves it. The justification lies in the wrong already done, not in any good results punishment might bring. For many people this matches a deep intuition: a person who has deliberately harmed another should answer for it, whether or not punishment will prevent future crime.

Kant

The most influential retributivist is the German philosopher Immanuel Kant. In The Metaphysics of Morals (1797), he argued that punishment can never be used merely as a means to promote some other good, for the offender or for society. It must be imposed only because the person has committed a crime. To punish someone just to set an example would treat them as a tool, which Kant thought violates human dignity.

Kant gave a famous illustration. Suppose the people of an island society agreed to dissolve their community and scatter across the world. Even then, he said, the last murderer in prison would first have to be executed, so that each person receives what their deeds deserve. The point of the example is that punishment, for Kant, is owed as a matter of justice even when it serves no future purpose.

Many retributivists add that punishment respects the offender. It treats them as a responsible adult who chose their act, rather than as a patient to be treated or an animal to be trained.

Proportionality

Retributivism insists that punishment fit the crime. The ancient principle of lex talionis, “an eye for an eye,” found in the Code of Hammurabi and the Hebrew Bible, is often read by historians as a limit on revenge: no more than the harm done. Modern retributivists rarely take it literally; no one proposes to burn an arsonist's house. Instead they stress proportionality. Ordinal proportionality means that more serious crimes should receive more severe punishments than less serious ones, and similar crimes similar punishments. Cardinal proportionality concerns the absolute level, such as whether the worst crime should receive ten years or life.

In the 1970s a just deserts movement in several countries revived these ideas, partly in reaction to sentencing systems that gave officials wide discretion to hold people until they were judged reformed.

Positive and negative retributivism

Positive retributivism says desert gives a reason, even a duty, to punish. Negative retributivism says desert sets limits: only the guilty may be punished, and never more than they deserve, but it does not by itself require punishment. Many mixed theories, like Hart's, use desert in this limiting way.

Retribution is not revenge

Defenders distinguish retribution from revenge. Retribution is imposed by an impartial authority, limited by proportionality and aimed only at the wrongdoer. Revenge is personal, has no built-in limit, may strike the wrongdoer's family, and often takes pleasure in suffering.

Criticisms

• Why does suffering help? Critics ask how adding a second harm to the first makes the world better.
• Measuring desert. How many years does a fraud deserve? Retributivism may give clearer rankings than absolute amounts.
• Responsibility. Desert assumes free and full responsibility, but offenders often face poverty, abuse, addiction or mental illness, which may reduce culpability.
• Disguised vengeance. Some suspect retributive language dresses up anger in philosophical clothing.

Defenders reply that desert is the strongest protection against punishing the innocent or punishing excessively, as the next level's objections to consequentialism show.

Worked example: two burglaries

Consider two invented offenders. Carl, aged 30, plans for weeks to break into an elderly neighbor's house while she is away, and takes her savings. Dev, aged 19, is homeless and addicted to drugs; on impulse he climbs through an open window and takes a laptop, which he sells the same day.

How would a retributivist approach their sentences?

1. Wrongfulness. Both committed burglary, but Carl caused greater harm: a larger loss, to a vulnerable victim, and a betrayal of a neighbor's trust.
2. Culpability. Carl planned carefully, which shows a settled choice. Dev acted on impulse under the pressure of addiction and homelessness. Many retributivists would see his culpability as somewhat lower, though still real.
3. Ordinal proportionality. On both counts, Carl's offense is more serious, so his punishment should be more severe than Dev's.
4. Cardinal proportionality. Exactly how severe? Here retributivism offers less guidance. Is Carl's crime worth two years, or five? The answer depends partly on the overall scale of penalties a society uses.
5. Negative retributivism. A negative retributivist would add that desert sets a ceiling. If a treatment program for Dev would do more good than prison, nothing in desert forbids choosing the milder option, provided it does not exceed what he deserves.

A critic might ask whether Dev's circumstances should count even more, since society may share responsibility for his situation. A defender replies that treating Dev as responsible also treats him as a person capable of choosing differently, which is a form of respect. The example shows that retributivism is not one sentence but a way of reasoning about seriousness and blame.