What conclusions about Macbeth‟s character can you draw from this soliloquy? Consider especially the question: why does the thought of killing Duncan affect in this way the man who has killed so many others on the battlefield, notably Macdonwald?
I'm thinking you mean Macbeth's first soliloquy. Killing Duncan is not like killing soldiers in the field. Elizabethans felt it was God's order that made Duncan king. Upsetting that order would most surely bring chaos to the universe, Macbeth is certainly aware that killing the king, his cousin and his sovereign leader, is the ultimate treacherous sin. Killing soldiers in battle is valiant while killings ones own King is a blasphemy against God.
