Crime and Human Rights (19): Why Do We Impose Criminal Punishment?

It seems so obvious that we must punish criminals that we hardly think about the reasons why. And then when we do think about some of the possible reasons, we find that they are of dubious quality, and we start to wonder whether criminal punishment can be justified at all.

1. Retribution

The first reason that springs to mind is retribution: we impose punishment – i.e. pain, suffering or unpleasant consequences – because that is what criminals deserve. Punishment is a deserved and proportionate “repayment” for the crime that has been done. And indeed, the fact that wrongdoers deserve some form of proportionate punishment or unpleasantness seems to be a deep-seated intuition. But if we want to use this notion of retribution as a justification of criminal punishment, we need to define what exactly it is that a particular criminal deserves. Because if it turns out that we can’t decide, in a non-arbitrary way, what it is that a criminal deserves, then it’s useless to place desert and proportional repayment at the heart of the justification of criminal punishment.

And we can’t decide. We can’t determine which punishment fits which crime. Retribution naturally tends towards lex talionis (an eye for an eye). For two reasons: first because that is the easy answer to the question of deserved punishment, and second because of the origins of the word “retribution” (retribuere in Latin means to restore, to give back). However, the brutality of lex talionis is no longer acceptable these days, which is why retribution theorists have tried to find another, less brutal way of determining the deserved punishment. Proportionality is then considered to be a just retributive principle: the punishment must not be equal to the crime, but the gravity of the punishment must be proportional to the severity of the crime; more serious crimes should entail more severe punishments.

Proportionality, like the element of desert in the basic structure of retribution, is hard to argue with, but it’s also useless. It can justify any type of punishment because it doesn’t provide a non-arbitrary starting point or end point of severity. Hence, it fails to answer the basic question raised by retribution: which punishment fits which crime? If this question can’t be answered, then retribution can’t be a justification of criminal punishment.

True, retribution can still be used negatively: some punishments clearly don’t fit the crime, and are not deserved. A $10 dollar fine for a murder, or execution for shoplifting are examples. But a theory of punishment that can only say which punishment are not justifiable is clearly not a complete justification of criminal punishment. After all, such a theory doesn’t exclude the possibility that all punishments are not justifiable.

2. Deterrence

With retribution out of the way, we can now consider an alternative justification of criminal punishment. We may decide to punish criminals because in doing so we instill fear in other – potential – criminals and therefore deter future crime. Punishment is then a means to protect society against crime. It’s a stop sign. And, like retribution, this seems to be, at first sight at least, a convincing justification. Like it is intuitively correct that a criminal deserves some kind of punishment, it is also intuitively convincing that people, when faced with the risk of punishment, will have a strong incentive to abstain from crime.

However, we again see that the initial appeal of this justification doesn’t survive closer scrutiny. First, there’s a lack of conclusive empirical evidence for the existence of a deterrent effect. Even the strongest possible punishment – death – doesn’t seem to deter. Part of the reason for this is the fact that crime often isn’t a rational calculation of risks, costs and benefits. And when it is, low conviction rates may have more weight in the criminals’ calculations than the severity or unpleasantness of unlikely punishments.

Another reason why deterrence cannot justify criminal punishment is its inherent immorality: to deter is to use people as means to reduce crime, and that kind of instrumentalization is morally unacceptable.

3. Incapacitation

If we can’t deter, maybe we can incapacitate, and justify criminal punishment on that basis. Incapacitating a criminal allows us to protect society without instrumentalizing the criminal (we don’t use the criminal and his punishment as a fear-instilling mechanism; we simply keep the criminal away from his or her future victims).

Again, being able to stop criminals from reoffending is intuitively appealing, but it isn’t enough to justify a system of criminal punishment. If we should decide that incapacitation justifies criminal punishment, we’re still left with the task of deciding the type of criminal punishment it actually justifies. Which actions are necessary and just forms of incapacitation? Like retribution or proportionality, incapacitation leaves open a very wide array of possible punishments: cutting off the hands of thieves, house arrest, ostracism, banishment, imprisonment, chemical castration, etc. A theory that can’t help us to choose among those options can’t possibly be a complete justification of criminal punishment. Ideally, we don’t want a justification of punishment that allows all or most types of punishment. And again, the fact that some forms of incapacitation are clearly not acceptable isn’t ground enough for a justification based on incapacitation, like the fact that some punishments are clearly not deserved isn’t ground enough for a justification based on retribution.

4. Symbolic confirmation of social rules

Perhaps a more promising justification of criminal punishment is based on the social role of punishment. When we punish criminals for their crimes, we may not intend to give them what they deserve, incapacitate them or deter others; we may instead engage in a bit of theater. Which, by the way, is also one of the reasons for having public trials. The public condemnation of wrong actions is a symbolic confirmation of social rules, and this confirmation has an educational function. It teaches people the values and norms of society, in the hope that they internalize these values and norms through repeated public and symbolic confirmation. Furthermore, the punishment of crimes affirms not just certain values and norms (e.g. don’t steal or murder) but the necessity of peaceful social cooperation and therefore the necessity of society itself.

Like desert, protection, deterrence and incapacitation, these are all fine objectives. However, a justification of criminal punishment based on its symbolic role faces the criticism of instrumentalization, as in the case of deterrence. Especially when the stated objectives – affirmation of norms and society – can be reached through other means.

5. Signaling

And the same is true for the justification of punishment based on the need for signaling. Society, and especially the representatives of society, need to show that they care about victims of crime. However, they don’t have to do so at the expense of criminals. Still less acceptable is the use of punishment as a signal of authority. Punishment can’t be justified when it is merely a manifestation of power by those in charge.

6. Healing and pacification

Punishment can be justified as therapy for the victims of crime, their relatives and friends, and even society as a whole. It’s a fact that punishment gives some satisfaction to victims, and responds to their sense of justice. It can also channel anger and revenge away from the more disturbing forms of those emotions, thereby preventing street justice and vigilantism. However, there’s a disturbing circularity to this justification: because people expect punishment, we should administer it, but because we administer it people continue to expect it. Also, when trying to channel emotions such as anger and revenge into socially acceptable forms we unconsciously promote them, whereas maybe we should try to limit those emotions as much as we can.

7. Rehabilitation

The rehabilitation of the criminal in the sense of his or her moral regeneration is no longer a fashionable justification of punishment. For several reasons: it’s expensive, and it upsets our sense of equal justice (successful rehabilitation can imply a radically shorter sentence). Also, some psychiatric excesses have been successfully ridiculed in movies such as A Clockwork Orange and One Flew Over the Cuckoo’s Nest.

In any case, the point is moot whether or not rehabilitation can be a successful justification of criminal punishment, since society has practically given up on it.


It’s extremely difficult to find an acceptable justification of criminal punishment. Hence, I strongly suspect that this is one of those social practices that seems perfectly normal and acceptable to contemporaries but also one for which we will be universally condemned by future generations.

Unsurprisingly, given the lack of solid justifications, people start to look for other reasons explaining the persistence of the practice. There’s talk of the new Jim Crow and criminal punishment being used to maintain oppressive social structures. Maybe it’s time to reread Foucault.

Still, it’s uncontested that society can’t function and people can’t thrive without respect for certain norms, especially the norms included in human rights. Those norms are regularly violated, and a society has the right and the duty to enforce compliance. A rejection of this right and duty means tolerating victimization and rights violations. But if punishment isn’t the right way to enforce compliance, which is? We can’t just accept punishment and to hell with justifications, because punishments do impose costs, both on the criminals being punished and on society as a whole. Imposing costs without justifications isn’t the right thing to do. Also, an unjustified system of punishment will lack legitimacy and will therefore be ineffective, something which will further undermine its legitimacy.

Hence, we’re left with the following choice: look harder for a justification, or find an alternative, non-punitive system of norm enforcement (maybe a system that is able to prevent violations of norms). Only half-jokingly: why not give law-abiding citizens prize money?

More here.

Crime and Human Rights (18): The Cruelty of Life Imprisonment Without Parole

My dismissal of capital punishment on moral grounds shouldn’t be understood as implying that this type of punishment is the worst possible one or that I’m ready to accept any other sentence in order to avoid executions. Life imprisonment without parole (LIWOP), for example, is often advanced as a good alternative to capital punishment and a means to convince people to drop their demand for that sentence. That makes LIWOP seem almost benign, which it isn’t. It’s particularly cruel, for reasons I discuss below.

That is why I tend not to argue as follows: capital punishment is bad because there is a less cruel punishment available – LIWOP – that does much of the things capital punishment is supposed to be doing (incapacitation, deterrence etc.). I argue instead that there are other reasons, beside overreach, not to use capital punishment. However, this post is not about those reasons, but rather about the reasons why we should also not use LIWOP.

Of course, “death is different” and capital punishment is particularly cruel. But LIWOP is also cruel, albeit mostly for other reasons. In one respect, it’s cruelty is similar to that of capital punishment. It’s irrevocable. The absence of parole means that “life” really is “life”. Of course, there’s often the possibility of clemency or appeal. But given the general “tough on crime” mentality among politicians and prosecutors, clemency for LIWOP cases is very unlikely, as are possible extensions of the right to appeal.

We also see, in the U.S. for instance, that clemency is more likely to be granted in capital cases than in cases of LIWOP since LIWOP is supposed to be “so much less cruel” (although also in capital cases the frequency of clemency is going down, most likely for the same “tough on crime” reason). Also, appeal procedures are much more developed in capital cases than in LIWOP cases. And when there is a successful appeal in a LIWOP case – for example because of new evidence of errors in the handling of the case – then these new elements are much less likely to be considered important enough to review the sentence, again because LIWOP is so much less “cruel”. Some people even argue that it is better to get a death sentence in the U.S. than LIWOP, because the appeals possibilities and clemency success rates are much higher. Especially innocent defendants have a much higher chance of getting their names cleared and escaping their sentence when they are convicted to die. Talking about irony.

Why does irrevocability make LIWOP particularly cruel? Some people say that LIWOP is a death sentence without an execution date. That in itself, however, may not make LIWOP cruel – you could say that all human beings are under a death sentence without an execution date, by the simple fact of human mortality. Still, LIWOP is a sentence to die in prison. It removes any prospect of change, rehabilitation or redemption. Whatever the prisoner does during his sentence, nothing is going to make any difference. Society tells these people that whatever they do, however much they try to redeem themselves, society’s not going to care. It’s not a sentence without an execution date, it’s an execution without a date: we basically tell these people that their lives are over. And we show this by withholding recreational and educational opportunities. Those resources, we say, are limited and better spent on prisoners who will get out some day. So that makes redemption not only useless but also impossible. It’s a self-fulfilling prophecy: we believe that they are irredeemable, and hence we treat them in such a way that they become irredeemable. If you don’t think that’s cruel, check your moral compass.

Opponents of capital punishment such as myself have to issue a mea culpa here. Our opposition has undoubtedly forced many more people into LIWOP. The number of LIWOP cases in the U.S. has risen dramatically, while the number of executions has fallen. One in every 35 prisoners in the U.S. is currently serving LIWOP (that’s about 41,000 people). This is the perverse and counterproductive result of well-intentioned activism. (See here for more counterproductive human rights policies). And it’s likely to become even more perverse: LIWOP cases, which tend to become more numerous as an alternative to capital punishment, don’t offer the same resources in terms of legal representation as capital cases, because people think there is less at stake, even when that’s clearly not true. Hence, a higher risk of miscarriages of justice, which are then harder to put right because of the lower probability of clemency and the less developed appeals procedures that also result from the idea that less is at stake.

So, what’s the solution? Well, obviously life with the possibility of parole. An argument in favor of LIWOP when compared to LIWP is that LIWOP is necessary for reasons of incapacitation. That is indeed a worthy goal of criminal punishment – if not the only goal -and some people do indeed deserve to be incapacitated for a very long time, perhaps even permanently. However, LIWP can also produce permanent incapacitation – by withholding parole when necessary – and can do it better because it can limit it to those prisoners for whom it can be shown, on an ongoing basis, that they are still dangerous. LIWOP means taking a decision about dangerousness once and for all, and then forgetting about the prisoner. The problem is that you can’t, at the moment of sentencing, make the decision that someone is going to be dangerous for the rest of his or her life. We simply don’t have the knowledge for such decisions. Psychology and psychiatry are not advanced enough yet, and will probably never be. Dangerousness has to be monitored continuously. People do change, except of course when the prison regime is such that they don’t get the opportunity or when the sentence is such that they don’t get the incentive.

And existing problems with parole (incompetent or lenient parole boards) are not a sufficient reason to favor LIWOP over LIWP. They are a reason to do something about those problems.

A country overview of the use of LIWOP is here and here.

Crime and Human Rights (13): What’s the Use of Criminal Punishment?

Criminal punishment, even in our non-medieval and so-called Enlightened societies, is the deliberate, intentional and organized imposition of harm on those we believe to be guilty of a crime. That remains the case even if we assume that those who are punished are in general guilty and that all necessary preconditions for criminal punishment are present (for example, that people are punished only after a fair trial, conducted by those authorized to conduct it; or that only those people aware of the moral significance of their actions are punished).

Given this imposition of harm, it’s important to be able to justify our systems of criminal punishment. Usually, but not always, the justifications people offer invoke the need to protect the rights of victims – actual or potential – but it’s far from certain that any justification can withstand even superficial criticism. Let’s look at the different justifications in turn. I think we can distinguish at least 5 common types of justification:

  1. Internalization
  2. Deterrence
  3. Rehabilitation
  4. Incapacitation
  5. Retribution

I’ll first offer a more or less neutral description of these different justifications, before criticizing them.

Justifications of criminal punishment

1. Internalization

The system of criminal punishment is justified because it is an expressive affirmation of shared values within a community (in other words, it’s a form of signaling). This affirmation serves to internalize shared values. When the members of the community have successfully internalized the shared values of the community, it’s assumed that crime will occur less frequently.

2. Deterrence

According to this second type of justification, criminal punishment is justified when it can be shown that the threat and practice of punishment is necessary for the prevention of future crimes, not through internalization of the norms expressed in punishment, but through fear of punishment. Punishment is supposed to reduce the prevalence of crime because it works as a threat. It’s assumed that most rational people who perceive this threat engage in risk analysis, weigh the possible costs and benefits of an intended crime, and conclude that the costs outweigh the benefits (the cost evaluation is a combination of likelihood of the threat – i.e. enforcement – plus severity of the threat). As a result, people reduce their willingness to carry out the crime.

3. Rehabilitation

Unlike internalization (1) and deterrence (2), this third type of justification does not aim at a general prevention or decrease in crime. Criminal punishment is justified because it prevents a particular criminal from engaging in future crimes. Prevention occurs because it’s believed to be possible to change the criminal’s propensity for crime through rehabilitative efforts within the penal system.

4. Incapacitation

This fourth type of justification also doesn’t aim at a general prevention or decrease of crime. Punishment is justified because it prevents a particular criminal from engaging in future crimes, not by way of rehabilitation but by way of incapacitation, which means either incarceration or execution.

5. Retribution

Criminal punishment is justified because criminals deserve to be punished in a certain way.

Consequentialism and deontology

Justifications 1 to 4 are consequentialist in nature: punishment is justified because of the good consequences that result from it, or because of the bad consequence that would result from our failure to punish. They all assume that punishment can prevent crime and hence protect victims – real or possible victims. Justification 5 is of a more deontological nature: punishment is a good in itself in the sense that it is required by justice irrespective of the likely consequences.

Contradictions between justifications

Notice how these different justifications may be incompatible.

Contradiction between (3) and (5)

Rehabilitation (3) means, by definition, flexible sentencing. Penal officials and judges need to have discretion, otherwise they can’t differentiate between successfully rehabilitated prisoners and others. Such discretion typically invokes anger among those who adopt a retributivist justification (5). Retributivism focuses on just desert in sentencing: a criminal should get the sentence he or she deserves, and usually this means a sentence that is in some way proportional to the gravity of the crime and to the harm done to the victim and to society. That is why retributivists demand uniformity in sentencing, and sometimes even mandatory sentencing. The discretion inherent in rehabilitation provokes feelings of unfairness among retributivists.

Contradiction between (4) and (5)

But also incapacitation (4) is often at odds with retributivism (5). For example, incapacitation in the form of incarceration may be less than what the criminal is supposed to deserve. Perhaps the criminal deserves to die according to the retributivist.

Contradiction between (2) and (5)

Retribution (5) can be incompatible with deterrence (2) because effective deterrence may require punishment that is more severe than the punishment that the criminal deserves. For example, there’s no reason why those who believe in deterrence should reject capital punishment for petty theft if it can be shown that such a punishment effectively deters this crime and that the benefits of deterrence outweigh the harm done by the execution. Something more is required to reject such a punishment, and that’s where retribution comes in. Retributivists would claim that petty thieves don’t deserve to die.

Contradiction between (3) and (4)

And a last example of a contradiction between different types of justification of criminal punishment: incapacitation (4) may make rehabilitation (3) more difficult. After all, it’s not obvious that prison is the best locus for rehabilitation. On the contrary, it’s often argued that prison is a school for criminals. Rehabilitation may then require a sentence such as a fine or GPS tracking.

A scale of decreasing ambition

We can view justifications 1 to 5 as being on a scale from most to least ambitious.

1. Internalization

Internalization (1) is obviously the most ambitious since it promises moral education of the citizenry and moral compliance with the law. The obvious problem here is that the desired outcome is highly uncertain, perhaps even utopian. It’s not sure that this uncertain objective justifies the very real harm imposed by criminal punishment.

2. Deterrence

Deterrence (2) is somewhat less ambitious since it discards the educational function of punishment as highly unlikely and aims instead at grudging compliance based on fear (as opposed to moral compliance based on conviction). Still, it’s relatively ambitious since it expects a society wide reduction in crime resulting from fear and rational risk analysis on the part of potential criminals. The data have shown that deterrence as well is overambitious.

3. Rehabilitation

Rehabilitation (3) in turn discards some of the unrealistic assumptions of deterrence (2), such as rationality on the part of future criminals and strict enforcement of the law, and tries to avoid some of the counterintuitive consequences of deterrence (2), such as the tendency to increase the severity of punishments resulting from the need to tip the scale in the risk analysis of criminals. It also tries to avoid the immoral instrumentalization inherent in deterrence. Moreover, it’s not clear that deterrence works, empirically.

Rehabilitation (3) is less ambitious than internalization or deterrence because it focuses on preventing only certain particular criminals from engaging in further crimes. There’s no society wide ambition anymore. However, the success of rehabilitative efforts during the past decades, as measured by reductions in recidivism, is mixed, to say the least. It’s correct to say that most criminologists have become somewhat disenchanted with rehabilitation. And there’s also some doubt about the morality of some rehabilitation techniques (especially those that have been lampooned in A Clockwork Orange). Which is why many have scaled back their ambitions even more and now focus on incapacitation (4).

4. Incapacitation

Let’s limit our discussion of incapacitation (4) to incarceration, since capital punishment is fraught with many other problems that have been widely discussed before on this blog. The problem with incapacitation is that it doesn’t have a clear boundary. Taken by itself, incapacitation theory could justify life imprisonment for petty crimes. In fact, the whole tough on crime philosophy can be seen as an exaggeration of incapacitation theory following the perceived failure of rehabilitation.

5. Retribution

This lack of a boundary in incapacitation theory (4) has led people to fall back on perhaps the oldest and least ambitious justification of criminal punishment, namely retribution (5). Retribution can be seen as a type of justification of criminal punishment that is entirely without ambition: punishment is inflicted for its own sake, not for the possible benefits it can produce. Criminals should be punished because it’s the right thing to do and because they deserve it, not because some aim or purpose can be served by it. This element of desert allows us to avoid both punishment that is viewed as being too severe – as in incapacitation (4) and deterrence (2) – and punishment that is viewed as being too lenient – as in rehabilitation (3).

Retributivism in fact abandons the pretense that punishment has a purpose, that it can achieve a desired objective and that no other, less severe means are available for this objective. However, retributivism isn’t a solid justification of criminal punishment either. It has proven to be impossible to know what exactly it is that the guilty deserve. Lex talionis is the easy answer, but it’s no longer a convincing one in modern societies. Proportionality is the difficult answer: severity in punishment should be proportional to the gravity of the offense. That’s the difficult answer because it leaves us with a system that is inherently imprecise and arbitrary. An infinite number of punishments are consistent with this justification. Hence it’s not really a justification at all.

No justification?

So, where does this leave us? It seems like criminal punishment is not justifiable. And indeed, there’s a long tradition in philosophy that views punishment as nothing more than rationalized anger, revenge and domination. Michel Foucault for example has analyzed criminal punishment as a cogwheel in the continuation of social power relations. The fact that there are so many African Americans in U.S. prisons and in execution statistics can be viewed as a symptom of continued racist domination. Nietzsche has described criminal punishment as being motivated solely by a deep natural desire to punish, subordinate and coerce. And indeed, if you want to punish someone for a crime, you first need to establish control over the would-be punishee. All systems of criminal punishment seems to be doomed to failure if there isn’t a prior system of control. This would indicate that there is already a prior system of control operating in society before criminal punishment takes effect, which in turn seems to indicate that systems of criminal punishment are merely the strong arm of deeper systems of control.

On the other hand, it seems difficult for anyone who’s serious about human rights to simply abandon criminal punishment. Without criminal punishment, we in fact expect victims of crime to either fend for themselves or undergo their suffering and rights violations. Neither outcome would be just.

Crime and Human Rights (10): Does Being Tough on Crime Reduce Crime?

The human right issues created by incarceration are evident, I think: locking people up means taking away a number if not most of their liberties, most obviously their freedom of movement, freedom to work, political freedom in some cases, and privacy. Other rights violations are also common, even in the prisons in rich countries such as the U.S.:

  • juvenile incarceration
  • the substandard conditions in which many prisoners are kept (Federal prisons in the U.S. hold 60% more prisoners than they were designed for)
  • the forced and unpaid labor prisoner often perform
  • the common occurrence of prison rape.

Some people clearly deserve to be put in jail, and often that is what is required in order to protect the human rights of their (possible) victims.

However, the “tough on crime” policies enacted in the U.S. and the resulting explosion in the numbers of U.S. citizens who are in prison (the U.S. has one of the highest incarceration rates in the world) go beyond what is required for public safety and the rights of victims. The causes of this explosion are numerous.

  • There’s the war on drugs, of course, which leads to excessively tough penalties, sometimes even for victimless crimes (the illegal sale of prescription painkillers for instance). Some of the penalties for drug “crimes” are tougher than the sentences for violent crimes.
  • There are other acts that are in essence victimless and need not be criminalized, and yet result in incarceration in the U.S. (e.g. importing rare orchids).
  • Sentences in the U.S. are too long. Many crimes come with mandatory minimum sentences, taking away judges’ discretion and their ability to take into account the specific circumstances of a crime. “Three strikes and you’re out” lead to life sentences for sometimes trivial crimes.
  • Some laws, especially laws regulating the conduct of businesses – are so vague that people have a hard time steering away from crime.
  • Prosecutors are often allowed to slice up a crime into a series of different crimes, each coming with a minimum sentence.
  • Parole conditions have been toughened, and people are regularly put back in jail for non-criminal violations of these parole conditions.

The cause of all this is probably the race to the top going on between politicians who are all promising to be tougher on crime than the next guy. Some judges in the U.S. are elected and engage in the same kind of bidding.

The question is: what are the benefits of this toughness, and what are the costs? Regarding the benefits, the homicide rate has been going down in the U.S., but it has since two centuries and it’s not clear that the tough policies introduced during the last decades have contributed much to the decline.

Bert Useem of Purdue University and Anne Piehl of Rutgers University estimate that a 10% increase in the number of people behind bars would reduce crime by only 0.5%. In the states that currently lock up the most people, imprisoning more would actually increase crime, they believe. Some inmates emerge from prison as more accomplished criminals. And raising the incarceration rate means locking up people who are, on average, less dangerous than the ones already behind bars. (source)

Regarding the costs: the prison system in the U.S. is extremely expensive, sucking away funds that could be used much more productively elsewhere, particularly on policies protecting human rights such as education. It’s also money that can’t be spent on better crime detection and better policing. It’s well-known that swift justice and high “catch rates” deter more crime than harsh penalties. If you want to be tough on crime, you shouldn’t necessarily choose the option of putting a lot of people away for a long time. And questioning the high incarceration rates in the U.S. doesn’t mean you’re weak on law and order.

High numbers of inmates also reduce the chances of rehabilitation: more prisoners means relatively less prisoners who can take advantage of the limited resources dedicated to vocational training and other activities that make it more likely that prisoners can become normal and non-reoffending members of society once they get out. Together with the phenomenon of prison as a “school for criminals”, this is likely to create a perverse effect: being tough on crime can actually increase crime. People should think hard on the way in which they choose to be tough on crime, and should consider if some crimes need to be crimes at all.

Capital Punishment (17): What With Rehabilitation?

As I live – declares the Lord Yahweh – I do not take pleasure in the death of the wicked but in the conversion of the wicked who changes his ways and saves his life. Ezekiel 33:11 (source)

I have been prey to the deepest anxiety for fear your Highness might perhaps decree that they [the murderers of a Catholic priest] be sentenced to the utmost penalty of law, by suffering a punishment in proportion to their deeds. Therefore, in this letter, I beg you by the faith which you have in Christ and by the mercy of the same Lord Chirst, not to do this, not to let it be done under any circumstances. … we do not wish that the martyrdom of the servants of God should be avenged by similar suffering, as if by way of retaliation. … We do not object to wicked men being deprived of their freedom to do wrong, but we wish it to go just that far, so that, without losing their life or being maimed in any part of their body, they may be restrained by the law from their mad frenzy, guided into the way of peace and sanity, and assigned to some useful work to replace their criminal activities. It is true, this is called a penalty, who can fail to see that it should be called a benefit rather than a chastisement when violence and cruelty are held in check, but the remedy of repentance is not withheld? Augustine (source)

We know enough to say that this or that major criminal deserves hard labor for life. But we don’t know enough to decree that he be shorn of his future – in other words, of the chance we all have of making amends. Albert Camus (source)

Execution obviously removes any possibility of rehabilitation; rehabilitation both in the sense of restoring someone to the family of humanity after repentance and forgiveness, and in the sense of exoneration, of the undoing of a miscarriage of justice.