That parental discipline may constitute a form of abuse depends entirely on what you accept under the label of "discipline". Consider for example a family in which following some religious practices - like preying before supper, or not eating certain kinds of food - is considered as part of a discipline that children are obliged to follow, and a 10 years old child (that is, someone who is cognitively able to take at least partly autonomous decisions on her moral preferences, even is she still doesn't have reached the institutionally established "age of reason", usually 16, 18 or 21 according to the countries) who refuses to comply. In this case, I would consider a sanction of her behaviour as a form of abuse. Punishing her for not complying to a rule she doesn't want to endorse because she finds it incompatible with her ideas and moral feelings is a form of abuse.

Abusing children means prescribing them a system of rules of disciplines without taking their stance and thinking about what is reasonable to accept now and in their future and what is questionable from their point of view now and in their future. Of course it is very difficult to evaluate what are the cases in which we have the right to act in an authoritative way with our children and cases in which we haven't this right, because given the asymmetry in experience, cognition and moral development between our children and us, very often we must force them to comply with practices and norms whose interest and value they cannot immediately understand.

One may argue that paternalism - that is, restricting the freedoms of dependants in what it is claimed to be their own interest - could serve as an appropriate moral test for parental discipline. But I don't think it suffices. In many cases we have the right to decide on behalf of our children in our own interest: we may for example proscribe some of children's actions or behaviours by appealing to the respect they owe us, that is, to the regard they should have to our way of living. So paternalism doesn't suffice to discriminate between legitimate and illegitimate coercion that we exerce on them.

A more plausible moral test for discipline would be the following: we can legitimately impose children to comply with some rules and practices if we consider our attitude towards the values these practices help to promote and the reasons why we endorse them. If the values these practices help to promote (hygiene, respect, instruction etc...) are values that we share and accept on a reasonable basis and not simply on authority, and furthermore we think we will be able in the future to articulate a reasonable explanation to our grown up children on why we decided to force them in such a way when we had control on their lives, then we can legitimately impose a discipline.

A different question is when punishment for not complying with parental discipline can be considered an abuse because, for example, it is too severe. Here I think we should take a long term perspective and balance the corrective effects of the punishment on education with long term effects of the punishment on the emotional and moral development of the child. For example, public humiliation, a form of punishment that was very common in schools and families, should be avoided, because its long term consequences may be extremely negative, whereas any form of punishment that involves taking the responsibility of an action (like for example learning to admit a fault), can have positive consequences on the way the child will conduct herself in the future. It will be useful also in this case to take the children's stance and try to "simulate" their understanding of the causal path which goes from their action to the punishment.

It is true that, once a person has been executed, she is no longer around to suffer the loss of years she might otherwise have lived. But the point of an execution is not to punish the person after she's dead, but before. She is subjected to the experience of living on death row and later to the experience of being killed in the execution chamber; and she must expect all along that many things she cared for are less likely to thrive or to come to fruition.

You might respond that this answer works only for people who know about their impending execution. What about someone who is killed painlessly in her sleep? Could this ever be construed as a punishment?

We can give an affirmative answer if we think of punishment in a somewhat extended sense as the setting back of a person's interests. Suppose you have given offense to someone and, in order to punish you, he has been embezzling money from your account. Being an affluent entrepreneur, you never notice the losses (you rather take your business to be less successful than it really is). But, nonetheless, there is a sense in which he really succeeded in punishing you. Your wealth is something you really care a great deal about, and it has really been substantially dimished over time below what it would be if he had not siphoned off money from your business account. Similarly, you might be punished by someone who is spreading false rumors about you that damage your reputation among the people who know you -- even if no one confronts you with these rumors and you thus remain ignorant of how your reputation has been gravely damaged.

Once we allow that there can be plausible cases of unexperienced punishments, then it may also be plausible to say that someone is punished after her death by setting back interests that were important to her. (After all, if the punishment is not experienced anyway, why should it matter whether the punished person is capable of such an experience at the time of the punishment?) By destroying the reputation of someone after her death, one can reduce the value of her life as she thought of it -- and likewise by destroying her best artwork (which she had ardently hoped would be admired by posterity).

Of course, this is stretching the ordinary notion of punishment a bit, but not, I believe, beyond recognition.

Of course, murder is not a victimless crime! But how can that be, Alex asks, if the victim no longer exists in order to suffer the harm that has been done to him? If you must exist in order to have interests, then how can a dead person’s interests suffer as a result of his death?

To see the harm that is suffered by a murder victim, let’s think first about what it means to be harmed. If I were to harm Harry, what sort of thing would I have to do him? Intuitively, when I harm Harry, my actions make him worse off than he would have been had I not acted as I did. So when I spread vicious gossip about Harry, I have harmed him because, had I not spread the vicious gossip, his reputation would have been intact, and he would have been well-respected in his community, loved by his family, and able to complete more easily certain projects about which he cares deeply, projects that require the good will and cooperation of others. Because of my vicious gossip, Harry is now a social outcast, unloved and unaided.

So let’s try out this definition of harm:

But now, it seems, we have a problem. If I kill Harry, how can we compare the state that Harry would have been in, had I not killed him, to the state that he’s now in, namely, dead? Since he is dead (and we’ll suppose, non-existent), he’s in no state at all. How can we compare this "non-state" to his state he would have been in had he been alive?

The answer to this puzzle, I think, is this. If Harry had survived, he would have attained all of the goods that generally come with living– pleasure, deep relationships with others, philosophical knowledge . . . (complete this list with whatever you count as genuine goods). Of course, had he lived, it’s likely that he would have had some hard times, too– some pain, frustration, heart-break, and so forth. But so long as his life would have been worth living for him, the goods that he would have had, had he survived, would have outweighed the bads that he would have had, had he survived. When I kill Harry, I prevent him from attaining these goods.

When we attempt to figure out the harm that Harry has suffered when I kill him, we should not compare Harry’s state after his death to the state that Harry would have been in, had I not killed him: for the reasons that I give above, such a comparison is impossible. Instead, when we attempt to figure out the harm that Harry has suffered when I kill him, we should compare the totality of goods that Harry would have had over the entirety of his life, had I not killed him, to the totality of goods that he had actually attained in the life that I cut off. If his life would have been worth living, then I did indeed harm Harry when I killed him: I deprived him of all of the goods that he would otherwise have had, had I not killed him.

The two statements in quotes are surely different. But the first can also express a moral standpoint: that it is morally important to achieve a low murder rate. This moral standpoint is reflected in various more specific claims.

1. We should not inflict punishment or pain on anyone unless doing so produces some good for others (e.g., by preventing the person from offending again or by deterring others).

2. We should inflict pain whenever doing so produces some greater good for others.

This second claim is highly problematic insofar as it may justify "punishing" the innocent when doing so helps deter real criminals. For this reason, those who hold deterrence to be morally important often claim instead:

3. In deciding how severely to punish specific types of crime, we should take into account how much of an impact greater severity would have on the frequency of this crime.

This third claim is consistent with the idea that people may be punished only for having done something wrong. But it allows two kinds of conduct that are equally wrong to be punished differently. One crime is punished lightly, yet some equally bad crime is punished more severely because here such punishment is more effective in getting the crime rate down. Moral arguments are made both for and against this claim.

It's apparently really expensive to shepherd a capital case all the way through to eventual execution--some say, much more expensive than life in prison.

http://www.deathpenaltyinfo.org/article.php?did=108&scid=7

That aside, there are plenty of other ethically relevant considerations. You can free a prisoner if the conviction is overturned, but you can't bring him back to life. Few of us, when actually faced with a choice, would choose death over life in prison. Nasty as it is, prison is not necessarily intolerable, and it may allow for the pursuit of important aspects of a good life. And even if capital punishment is already used for some particularly horrible crimes, expanding it to others may face objections of the sort people raise against capital punishment in the first place, to do with fairness of application, the value of life, the inhumanity of easily avoidable killing, and the merits of mercy. Even if these objections did not convince you to keep the mass murderer alive, they might move you with respect to the enraged spouse or the drug dealer or the white-collar felon. They might not, certainly, but they need at least to be considered before you can reasonably judge that it's at least as good to kill these people as to lock them up.

Any realistic criminal justice system will make both types of error: T-errors (terrible future crime committed by one wrongly acquitted) and I-errors (innocent person wrongly convicted).

It seems morally more appropriate here to compare alternative systems feasible for the same society in terms of the total number of errors, not in terms of the ratios you focus on (ratio of T-errors to total number of acquitted, ratio of I-errors to total number of convicted). To see this, take a criminal justice system under which 100,000 are acquitted of whom 2000 are wrongly acquitted and go on to commit a terrible crime. Now suppose we modify this system so that many more innocent people are tried and properly acquitted. So now we have 200,000 acquitted of whom 2000 are wrongly acquitted and go on to commit a terrible crime. So we got the T-error rate from 2 percent down to 1 percent. But have we improved the system? Surely not.

So I rephrase your question this way: In designing our criminal justice system, should we give greater weight to avoiding T-errors or to avoiding I-errors?

There is a widely held view bearing on this question. In one famous formulation by William Blackstone (www.law.ucla.edu/volokh/guilty.htm), it says: “It is better that ten guilty persons escape than one innocent suffer.” I think what stands behind this view is the idea that we as a society bear a far weightier responsibility for harms to innocents that we directly bring about than for harms to innocents that we merely might have prevented.

This idea is familiar in pedestrian contexts. It would be wrong to kill one innocent person in order to save another. It would be wrong to harm one innocent person in order to rescue another from a similar harm. It would be wrong to risk the life of one innocent person to prevent a risk to the life of another (risks being equal). And it would be wrong to cause a risk of harm to one innocent person in order to prevent the same risk of harm to another. In all these cases, agents ought to give more weight to harms and risks of harm they directly bring about than to similar harms or risks of harm that they merely fail to prevent.

This almost answers the reformulated question: We should give greater weight to avoiding I-errors than to avoiding T-errors. I say "almost", because the average harm associated with errors of each kind may not be equal. So the conclusion might conceivably be overturned if the harm done by the average I-error is just a few days in jail without public stigma while the average harm resulting from the average T-error is a minor massacre. But this is not true in the real world. Here, in order seriously to reduce the number of terrible crimes committed by persons wrongly acquitted, we would have to make it easier to convict people accused of very serious crimes and then take those convicted out of circulation for very long periods or forever. And doing this will inevitably increase the number of innocent people who, wrongly convicted, are locked up for very long periods or even executed.

I agree that your solution works as well or better. Here are two different arguments a consequentialist might make.

(1) Suppose all attempted murders are punished equally, regardless of success, with each attempt being punished with 6 years in jail and 30% of punished attempts successful. Now consider this reform: We increase punishment for successful attempts from 6 to 13 years and decrease punishments for unsuccessful attempts from 6 to 3 years. This reform leaves constant the jail time per punished attempt (which consequentialists typically count as a negative): 13 x 30% + 3 x 70% = 6. (Obviously, the numbers here are just for illustration.) But the reform is likely to increase deterrence, because prospective murderers are going to focus more on the "successful" outcome that risks a 13 year penalty than on the (actually more likely) "unsuccessful" outcome that risks a 3 year penalty. As a result of better deterrence, fewer murder attempts are made, fewer people are murdered, and fewer years are spent in jail. (Obviously, for this argument to work, I must be right about the psychology of prospective murderers.)

(2) Whether an attempted murder succeeds or not is sometimes due to luck. But it is often correlated with features of the agent (greater relevant abilities, will power, nerve, lesser moral scruples, and so on). Therefore, those whose murder attempt succeeds tend to be more dangerous, on average, than those whose murder attempts fail. Also, given that criminals often commit further crimes, an extra year in jail for a more dangerous criminal better protects the public from repeat offenses than an extra year in jail for a less dangerous offender. It therefore makes sense to shift jail time from unsuccessful to successful attempters.

..... But, if these are good arguments, might consequentialists want to advocate that only successful attempts should be punished?