I agree. Some of the most violent criminals can't ever be re-integrated into society, so the only alternative is life imprisonment. I've seen many arguments that this is preferable to the death penalty because "We will accidentally execute some innocents", as Paul Graham's here, as well as "It costs more to execute someone due to the higher standard of proof required".
In all such cases the corollary is "We can accept a lower standard of proof because we're not actually killing them. We're just locking them in a room forever and waiting until they die." I don't honestly see much difference between these outcomes. Why is one so morally superior to the other?
There are much better arguments against the death penalty. One is that if the death penalty exists, it's much easier for the state to execute political dissidents. If the death penalty is abolished (and there are strong controls on extra-judicial killings, like police murdering civilians during arrests), it's much more difficult for the state to silence critics. Even if they are locked away in jail forever, they will still have a voice.
Another good argument is that if the death penalty is a possibility it gives criminals nothing to lose which makes it more dangerous to apprehend them. If you want your police to be able to more peacefully arrest criminals, it makes sense to abolish the death penalty.
In all such cases the corollary is "We can accept a lower standard of proof because we're not actually killing them. We're just locking them in a room forever and waiting until they die." I don't honestly see much difference between these outcomes. Why is one so morally superior to the other?
There are much better arguments against the death penalty. One is that if the death penalty exists, it's much easier for the state to execute political dissidents. If the death penalty is abolished (and there are strong controls on extra-judicial killings, like police murdering civilians during arrests), it's much more difficult for the state to silence critics. Even if they are locked away in jail forever, they will still have a voice.
Another good argument is that if the death penalty is a possibility it gives criminals nothing to lose which makes it more dangerous to apprehend them. If you want your police to be able to more peacefully arrest criminals, it makes sense to abolish the death penalty.