Furthermore, given the injust behaviour of most modern states as well as their general illegitemacy – what really distinguishes capital ‘punishment’ from mere revenge killings?

My views here are more focussed on the philosophical problems that opponents would have to get over in order to succeed, rather than advocating we should actually have the DP. If we are to take moral imperatives seriously (‘do not kill’) we should minimise the excuses we use to contravene them. I wouldn’t actually want such a punishment as part of our justice system, but in a purely philosophical sense, it seems to me that some of the anti arguments just happen to be bad arguments even if I agree with their conclusions.

Turning to your last statement, do you not think a distinction can be made between justice on the whim of the people, and harsh punishments but through consistent, thorough, even objective state institutions? In other words, capital punishment could be exercised just as legitimately as any other punishment, without getting the mob involved. Also, I think you make the point that death is ‘vengeful’, but, I’m not sure that other punishments should be automatically ennobled by being presumed to be free from vengeance: “I Hope s/he rots in jail!” seems pretty vengeful to me. Furthermore, it could well be wondered whether removing justice from the whims of the people necessarily substitutes a less harsh justice just because the operations of the state are capable of being consistent and detached. One of the chilling aspects of capital punihsment, to me, is just how clinical and detached it actually can be.

So some of the arguments against captial punishment seem to be begging the question without acknowledging or realising it. I can’t help but feel that if one is to be intellectually honest, the DP should be argued around, from the same ground as other punishments, rather than against, by various forms of special pleading from vague notions of wrong and justice. This, and I think you said it earlier, calls for questions on what we actually want (and what we really don’t want) out of a system of public punishment. I don’t want the state killing people, but I’d shy from appealing to special moral authority to support that view.

The arguments that I tend to find convincing are those that argue for ‘punishments preferable to death’, rather than relying on the logical sleight of hand that death is somehow an inherently less legitimate form of punishment than imprisoning somebody for life.

As an aside, I think there are lots of more useful and efficient forms of state sanction than prison (and capital punishment probably isn’t one of them).

I’d say justice serves all of those purposes. It’s hard to escape the conclusion that we’re simply trying to justify what we already do (and want to do), when speaking of justice as though it’s some abstract product of pure reason: such a concept of justice would be “nonsense on stilts”, in Bentham’s words. Following from this, I don’t think there is any logical way of sort of ‘discovering’ the foundational requirements of justice (though reasoning its applications can be done entirely through deductive argument), as I think we stumble on the is-ought problem pretty quickly if we were to try and make any claims of that nature. In other words, the question, “what does justice [or punishment] demand, generally” is less reducible than the question “what does justice [or punishment] demand of this particular situation”. That’s why I think a preference-ultility argument is the most successful when arguing against the DP (or any punishment at all).