Wow new post after a year!
Right, so I was involved in this conversation about the nature of murder for some reason. What the other guy(s) were arguing was that, because the law defines 'murder' as the deliberate killing of another human being, therefore all killing of humans was murder, including executions and warfighting, except that two latter two happen to be lega kinds of murder.
I thought that this was a highly facile and, well, stupid argument, but I'm not exactly the best debater, so my attempts to argue to the contrary came out as a bunch of bwahahrghar and stuff.
Thankfully I've thought about it for a while now so I can provide what I think is a reasonably sound argument as to why 1) Not all killings are murders, 2) Some killings are justified, if regretable.
What is murder?
When one defines "murder" as the deliberate killing of another human being, one is only partly right. Why is this killing forbidden and not others, like capital punishment? It all has to do with purpose and rights.
Purpose and rights
There are two major concepts at stake here: the natural rights of individual human beings and the common good. When a murder is committed it is because the former has been violated for no other reason than the will of the murderer; he kills another because of some private quarrel, or for money, or for some other advantage that the death of that person is seen to bring. He is doing it for himself, and therefore he is imposing his own will against the natural right of another person to be alive.
But what about executions, which some cynics/hippies regard as "state-sanctioned murder"? This is a totally different matter. The reason why the state makes laws that allow the killing of some criminals is to preserve the common good. That is, the person poses such a threat to the security of the whole community that it is better that he perish than be allowed to live. This is a very loose argument for capital punishment, but the point is clear: the state is allowed, in certain very limited circumstances, to execute criminals for the common good of the society which it governs.
War is similar. In a just war, a state sends its soldiers to fight and defeat the enemy in order to protect not only itself but also the people; war is the ultimate action in which the common good, directly threatened, is preserved. Inevitably, fighting will involve killing, but as long as a reasonable level of force is applied (which is another argument entirely) then the killings are justified because the survival of the state and of the common good is at stake.
All of this is akin to the idea that one has a right to self-defence even until the point of killing the aggressor. Just as a person as a right to preserve his life, so the state has a right to preserve the welfare and integrity of the community/nation.
In all these cases, the common good, in a sense, "overrides" the natural rights of individuals to live. There are very important caveats, of course, for not even the community/state can demand absolute rights, but the purpose of this missive has been merely to lay out a basic argument regarding the distinction between the different kinds of killing, legal and illegal.