Conflicting aspects of Human nature

During Mondays class we touched upon the idea of there potentially being conflicting aspects of human nature. I was thinking that this directly tied into last weeks discussions about consuming other animals. Could it be that human nature is to eat other creatures, and also to do what we believe makes us a better person? If so the idea of killing another animal for consumption would definitely create tension, and as a result we will use cognitive dissonance to justify our actions.