At a glance, I don’t think I’ve seen the following points made, so I’ll do so:
The general approach from math and the sciences is to make the definitions rigorous, from which the intended conclusions will necessarily follow. For example, any object of mass 10kg near Earth’s surface will experience a force of roughly 98.1 N toward’s Earth’s center due to Earth’s gravity. There is no “non-central example” of “an object of mass 10kg near Earth’s surface”—well, perhaps I should specify what “near” is, for example as being within 1% of 6371 km of the km. Then quantifying that allows me to quantify “roughly” as well, by plugging in GmM/r^2 for the minimum and maximum of the radius values.
Observe how we refine both the conditions and the conclusions in the above.
Arguments that have been refined in this way will be of the form “1. Object X meets the conditions of belonging to group Y. 2. It is a theorem that statement Z applies to all objects in group Y. 3. Therefore Z(X).”
If you have the proof of the theorem at hand, then it should be easy to taboo the name of group Y and just plug X into the text of the proof and get an equally rigorous argument. Sometimes that would be a better approach to the whole issue; though if group Y is common enough, it might be worth the work of establishing the definition.
To apply it to the “taxation is theft” argument: Well, basically, we want to make a rigorous definition of “theft” (or possibly a new term) that covers taxation, and see how much we can retain.
Taxation is nonconsensual taking of someone’s rightful property (some might argue about “consent” in a democracy; let’s assume that Bob is objecting to being taxed, and he did everything he could to vote against it, to support politicians who said they would reduce or even abolish taxes, etc., yet was unsuccessful). We would therefore be able to make arguments like “under certain moral systems, taxation is immoral”, and “because it doesn’t require the consent of those being taxed, even if some instances of taxation were net good in some way, we’d expect to end up with a lot more instances than that unless there were strong barriers preventing it”, and “taxation reduces people’s incentive to trade their labor for property, because some of that property will go missing”, and “taxation incentivizes people to spend energy arranging their possessions in ways that are less likely to get taken, which is a waste”.
On the other hand, certain other characteristics that are common in theft are not the case: taxes are generally mostly known in advance, while theft is mostly unpredictable; and where theft might take a poor-ish person whose primary asset is a car and suddenly bankrupt them, taxes are unlikely to do that.
Taxation is centralized, systematized theft. The systematization has its benefits and civilizing effects: economies of scale and reduced risk and variation in the collection process—similar to what you get when you industrialize other processes. Also, we probably benefit from a “tragedy of the commons” among those who receive the taxes: most individuals don’t have a strong incentive to raise taxes a lot.
For murder and capital punishment: Let’s first note that the legal profession has made distinctions: “first-degree murder”, “second-degree”, etc. (it seems to vary by jurisdiction), not to mention manslaughter, and of course there are cases like self-defense where it may not even be a crime. “Homicide” is what they call “killing” without implying anything about the legality. First-degree murder, the worst, seems to mean “murder pre-meditated in cold blood”, while the lesser degrees apply when there are extenuating circumstances and less pre-meditation.
Executing a prisoner is 100% pre-meditated in cold blood. The argument for it to be legal is to cast it as self-defense and/or revenge. Are revenge killings legal? It seems like they sort of used to be, and then at some point States generally disallowed individuals from doing it, while arrogating that function to itself. As for self-defense… one could argue that the criminal, having committed their crimes (like murder), has shown they are a threat, but really that’s not a strong enough data point. (What fraction of murderers do it again? … A Google result says between 2% and 16% for different groups. What if they killed their brother out of enmity that began in childhood, and they have no more brothers? Also, “got drunk and angry in a bar argument and killed a stranger” is a lot more likely to recur, yet would probably be second-degree, while the “brother” scenario might be first-degree.)
Capital punishment is centralized, systematized revenge-killing. Once again, the systematization brings benefits and civilizing effects: economies of scale, reduced risk and variation. I would not say that this changes the morality of it, only the tactical utility. (I haven’t actually said whether I think revenge-killing itself is moral.)
Anyway, on the subject of the original frame—”capital punishment is murder”, given the definition “murder = killing without proper justification”, is assuming the conclusion—that capital punishment should be illegal. If you want a different definition, I would say use a different term. If it were “capital punishment is killing”, that would be an uncontroversial statement of fact; nor would the argument “killing is necessarily bad” persuade more than a few pacifists.
“Capital punishment is revenge-killing” would be the closest to an argument we can break into its pieces, “killing people for retaliation is bad (to the point where we should have a policy against it)” and “capital punishment is a policy of killing in retaliation”, and attempt to justify both pieces. Though some of the arguments people would like to make, like “revenge killings generally lead to generations-long family feuds”, would not extend to the State’s centralized revenge killings; in constructing or evaluating such arguments, the key technique of rigor is to notice statements that are actually “(we’ve seen in the past that) revenge killings (often) lead to family feuds” when they should be “(we can prove that) revenge killings (necessarily create conditions that likely) lead to family feuds”, and in trying to prove that you should either notice that the definition of “revenge killing” doesn’t specify that it’s carried out by a family member—or, if it does, then notice that clause of the definition doesn’t apply to capital punishment.
At a glance, I don’t think I’ve seen the following points made, so I’ll do so:
The general approach from math and the sciences is to make the definitions rigorous, from which the intended conclusions will necessarily follow. For example, any object of mass 10kg near Earth’s surface will experience a force of roughly 98.1 N toward’s Earth’s center due to Earth’s gravity. There is no “non-central example” of “an object of mass 10kg near Earth’s surface”—well, perhaps I should specify what “near” is, for example as being within 1% of 6371 km of the km. Then quantifying that allows me to quantify “roughly” as well, by plugging in GmM/r^2 for the minimum and maximum of the radius values.
Observe how we refine both the conditions and the conclusions in the above.
Arguments that have been refined in this way will be of the form “1. Object X meets the conditions of belonging to group Y. 2. It is a theorem that statement Z applies to all objects in group Y. 3. Therefore Z(X).”
If you have the proof of the theorem at hand, then it should be easy to taboo the name of group Y and just plug X into the text of the proof and get an equally rigorous argument. Sometimes that would be a better approach to the whole issue; though if group Y is common enough, it might be worth the work of establishing the definition.
To apply it to the “taxation is theft” argument: Well, basically, we want to make a rigorous definition of “theft” (or possibly a new term) that covers taxation, and see how much we can retain.
Taxation is nonconsensual taking of someone’s rightful property (some might argue about “consent” in a democracy; let’s assume that Bob is objecting to being taxed, and he did everything he could to vote against it, to support politicians who said they would reduce or even abolish taxes, etc., yet was unsuccessful). We would therefore be able to make arguments like “under certain moral systems, taxation is immoral”, and “because it doesn’t require the consent of those being taxed, even if some instances of taxation were net good in some way, we’d expect to end up with a lot more instances than that unless there were strong barriers preventing it”, and “taxation reduces people’s incentive to trade their labor for property, because some of that property will go missing”, and “taxation incentivizes people to spend energy arranging their possessions in ways that are less likely to get taken, which is a waste”.
On the other hand, certain other characteristics that are common in theft are not the case: taxes are generally mostly known in advance, while theft is mostly unpredictable; and where theft might take a poor-ish person whose primary asset is a car and suddenly bankrupt them, taxes are unlikely to do that.
Taxation is centralized, systematized theft. The systematization has its benefits and civilizing effects: economies of scale and reduced risk and variation in the collection process—similar to what you get when you industrialize other processes. Also, we probably benefit from a “tragedy of the commons” among those who receive the taxes: most individuals don’t have a strong incentive to raise taxes a lot.
For murder and capital punishment: Let’s first note that the legal profession has made distinctions: “first-degree murder”, “second-degree”, etc. (it seems to vary by jurisdiction), not to mention manslaughter, and of course there are cases like self-defense where it may not even be a crime. “Homicide” is what they call “killing” without implying anything about the legality. First-degree murder, the worst, seems to mean “murder pre-meditated in cold blood”, while the lesser degrees apply when there are extenuating circumstances and less pre-meditation.
Executing a prisoner is 100% pre-meditated in cold blood. The argument for it to be legal is to cast it as self-defense and/or revenge. Are revenge killings legal? It seems like they sort of used to be, and then at some point States generally disallowed individuals from doing it, while arrogating that function to itself. As for self-defense… one could argue that the criminal, having committed their crimes (like murder), has shown they are a threat, but really that’s not a strong enough data point. (What fraction of murderers do it again? … A Google result says between 2% and 16% for different groups. What if they killed their brother out of enmity that began in childhood, and they have no more brothers? Also, “got drunk and angry in a bar argument and killed a stranger” is a lot more likely to recur, yet would probably be second-degree, while the “brother” scenario might be first-degree.)
Capital punishment is centralized, systematized revenge-killing. Once again, the systematization brings benefits and civilizing effects: economies of scale, reduced risk and variation. I would not say that this changes the morality of it, only the tactical utility. (I haven’t actually said whether I think revenge-killing itself is moral.)
Anyway, on the subject of the original frame—”capital punishment is murder”, given the definition “murder = killing without proper justification”, is assuming the conclusion—that capital punishment should be illegal. If you want a different definition, I would say use a different term. If it were “capital punishment is killing”, that would be an uncontroversial statement of fact; nor would the argument “killing is necessarily bad” persuade more than a few pacifists.
“Capital punishment is revenge-killing” would be the closest to an argument we can break into its pieces, “killing people for retaliation is bad (to the point where we should have a policy against it)” and “capital punishment is a policy of killing in retaliation”, and attempt to justify both pieces. Though some of the arguments people would like to make, like “revenge killings generally lead to generations-long family feuds”, would not extend to the State’s centralized revenge killings; in constructing or evaluating such arguments, the key technique of rigor is to notice statements that are actually “(we’ve seen in the past that) revenge killings (often) lead to family feuds” when they should be “(we can prove that) revenge killings (necessarily create conditions that likely) lead to family feuds”, and in trying to prove that you should either notice that the definition of “revenge killing” doesn’t specify that it’s carried out by a family member—or, if it does, then notice that clause of the definition doesn’t apply to capital punishment.