Logic and Emotion

I tended to think that logic and emotion are mutually exclusive. When I was working in Japanese government, I should be logical rather than emotional to persuade my idea was better than other ones. However, I come to change my mind after taking an ethics class here. I found that logic reaches emotion more often than I had expected. Let's say there is a question “why shouldn’t we kill other people?” Some people may say because this impairs other people’s liberties. Then next question comes. Why shouldn’t we impair other people’s liberties? Some may say because it is very precious. Again, why is it precious?,,, If we try to rely on only logic, we cannot finish the sequence. This is because some emotion or intuition is necessary to stop the logical sequence. I do not mean logic is not important, but emotion is also necessary part of logic sometimes.