The theory of criminal justice is the branch of philosophy of law that deals with criminal justice

Criminal justice

Criminal Justice is the system of practices and institutions of governments directed at upholding social control, deterring and mitigating crime, or sanctioning those who violate laws with criminal penalties and rehabilitation efforts...

 and in particular punishment

Punishment

Punishment is the authoritative imposition of something negative or unpleasant on a person or animal in response to behavior deemed wrong by an individual or group....

. The theory of criminal justice has deep connections to other areas of philosophy, such as political philosophy

Political philosophy

Political philosophy is the study of such topics as liberty, justice, property, rights, law, and the enforcement of a legal code by authority: what they are, why they are needed, what, if anything, makes a government legitimate, what rights and freedoms it should protect and why, what form it...

 and ethics

Ethics

Ethics, also known as moral philosophy, is a branch of philosophy that addresses questions about morality—that is, concepts such as good and evil, right and wrong, virtue and vice, justice and crime, etc.Major branches of ethics include:...

, as well as to criminal justice in practice.

Some important questions considered in the theory of criminal justice are

• What is criminal justice?
• How is criminal justice distinct from other kinds of justice (or is it in fact distinct)?

Some questions specific to the topic of punishment are

• Should we punish?
• Why should we punish?
• Whom should we punish?
• How should we punish?
• How much should we punish?

How is criminal justice distinct from other kinds of justice?

Typically, legal theorists and philosophers consider four distinct kinds of justice: corrective justice, distributive justice, procedural justice, and retributive justice. Criminal law falls under retributive justice, a theory of justice that considers proportionate punishment a morally acceptable response to crime. Retributive justice is perhaps best captured by the phrase lex talionis (the principle of "an eye for an eye"), which itself traces back to the book of Exodus. The principle of lex talionis received its most well known philosophical defense from Immanuel Kant.

Criminal law is no longer considered a purely retributive undertaking; detterence figures prominently in the justification of the practice and in the rules themselves.

Criminal justice systems

There are at least two questions, raised by H. L. A. Hart

H. L. A. Hart

Herbert Lionel Adolphus Hart was an influential legal philosopher of the 20th century. He was Professor of Jurisprudence at Oxford University and the Principal of Brasenose College, Oxford. He authored The Concept of Law....

, in connection with criminal justice which do not directly concern punishment but are more closely related to a criminal justice system as a whole.

• Why establish any institution of punishment at all?
• Why establish this institution with its special concepts, principles of legislation, adjudicative procedures, and permissible penalties rather than some other?

Punishment

Different theories of criminal justice can usually be distinguished in how they answer questions about punishment. To avoid issues of semantics

Semantics

Semantics is the study of meaning. It focuses on the relation between signifiers, such as words, phrases, signs and symbols, and what they stand for, their denotata....

, in this section we must agree that punishment is a penalty

Sanctions (law)

Sanctions are penalties or other means of enforcement used to provide incentives for obedience with the law, or with rules and regulations. Criminal sanctions can take the form of serious punishment, such as corporal or capital punishment, incarceration, or severe fines...

 imposed by a legal system along with (or because of) a stigma

Social stigma

Social stigma is the severe disapproval of or discontent with a person on the grounds of characteristics that distinguish them from other members of a society.Almost all stigma is based on a person differing from social or cultural norms...

 of wrongdoing

Wrong

A wrong or being wrong is a concept in law, ethics, epistemology, and science. In a colloquial sense, wrongness usually refers to a state of incorrectness, inaccuracy, error, or miscalculation in any number of contexts...

 or lawbreaking

Law

Law is a system of rules and guidelines which are enforced through social institutions to govern behavior, wherever possible. It shapes politics, economics and society in numerous ways and serves as a social mediator of relations between people. Contract law regulates everything from buying a bus...

. This definition deliberately excludes penalties unrelated to wrongdoing or lawbreaking, even when imposed by a legal system. It also distinguishes or at least restricts this definition from the one used in operant conditioning

Operant conditioning

Operant conditioning is a form of psychological learning during which an individual modifies the occurrence and form of its own behavior due to the association of the behavior with a stimulus...

.

Should we punish?

The answer to this question is important as a negative answer makes further questions about punishment irrelevant. In fact, if we answer no, then the theory of punishment does not even belong in the theory of criminal justice.

Most theories answer yes, that there are at least some criminals or criminal acts

Crime

Crime is the breach of rules or laws for which some governing authority can ultimately prescribe a conviction...

 that should be punished. However, this question should not be so easily dismissed as there are theories which do answer no. Consider, for example, Pacifism. Also, certain versions of restorative justice

Restorative justice

Restorative justice is an approach to justice that focuses on the needs of victims, offenders, as well as the involved community, instead of satisfying abstract legal principles or punishing the offender...

 might optimistically make the claim that punishment is unnecessary.

Whom should we punish?

We should punish criminals. Unfortunately, the answer is not that simple. Should we punish only lawbreakers, or other wrongdoers? Should we punish all criminals? Often, the answers to these questions are interrelated with the reasons for punishment.

For example, if the reason for punishment is rehabilitation, then we should not punish criminals who show genuine remorse

Remorse

Remorse is an emotional expression of personal regret felt by a person after he or she has committed an act which they deem to be shameful, hurtful, or violent. Remorse is closely allied to guilt and self-directed resentment...

. In practice, this is difficult to determine.

The question of whether only lawbreakers can be punished is connected to the validity of retroactive laws. Whether wrongdoers can and should be punished under retroactive laws was particularly important around the end of World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. Many Nazi

Nazism

Nazism, the common short form name of National Socialism was the ideology and practice of the Nazi Party and of Nazi Germany...

 war criminals

War crime

War crimes are serious violations of the laws applicable in armed conflict giving rise to individual criminal responsibility...

 were tried under laws which were not in place at the time they committed their so-called crimes. Although their actions were wrong, their punishment brings up important issues. Punishment under retroactive laws can not possibly accomplish deterrence.

How should we punish?

Different methods of punishment can be evaluated based on effectiveness, cost efficiency, and on moral grounds.

There is a principle in certain versions of retributive theory that can be stated as "an eye for an eye

An eye for an eye

The meaning of the principle, an eye for an eye, is that a person who has injured another person receives the same injury in compensation. The exact Latin to English translation of this phrase is actually "The law of retaliation." At the root of this principle is that one of the purposes of the...

". This principle argues for punishment in kind with the harm that was caused by the wrongdoer.

Cruel and unusual punishment

Cruel and unusual punishment

Cruel and unusual punishment is a phrase describing criminal punishment which is considered unacceptable due to the suffering or humiliation it inflicts on the condemned person...

is outlawed in many legal systems, presumably on moral grounds.

How much should we punish?

Deterrence theory argues that the amount of punishment should be the minimum required to achieve the desired amount of deterrence. Most versions of retributive justice argue that the amount of punishment should be proportional to the amount of harm caused. Reform theory argues that the amount of punishment should be enough to cause reform in the offender.

However, some theories would argue that the amount of punishment is not important at all. For example, if the purpose of punishment is incapacitation, the fact that a jail sentence is undesirable to the offender is irrelevant.

Types of theories

Theories may be of following kind:

1. Deterrent Theory
2. Retributive Theory
3. Reformative Theory
4. Expiatory Theory
5. Preventive Theory