The Morality of Killing

At first sight there doesn't seem to be any problem about killing. Most people would say that it is wrong to kill and that's all there is to it. The same opinion is proclaimed by many members of the Christian religion. They say that ‘Thou shalt not kill’ is an absolute command. But there are several issues involving the morality of killing where ordinary men, secular and religious alike, make judgements or evince perplexity which reveals that common sense morality is less clear about killing than it at first appears.