I include neither torture nor death penalty in my definition of a civilized society.

Let's say you are a cop with a gun. There a criminal who threatens to cut of someone's finger and then hand itself in.

Should the cop be allowed to kill the criminal by shooting him? Our laws say, yes. It's a defensive act. Killing the criminal to prevent the finger from being cut of is right.

With torture it's a different matter. If a criminal did hid a hostage somewhere, we don't allow the cop to torture the criminal to give up the location of the hostage.

We value the good of not torturing higher than the good of not killing. If you look at the US constitution you will find a list of values. Those are all important. You won't find "don't kill" in that list, just "nor be deprived of life, liberty, or property, without due process of law".