Evil. We are all born with the capacity to hurt, to be spiteful and cause suffering towards others, but not all of us are born with the capacity to be forgiving, kind and selfless. We have all gone mad with power before at some point in our lives, even in ludicrously little and meaningless ways, and that feeling is likely to have been the catalyst to every truly monstrous person in history. If given the chance, the majority of people would gladly step over theirs neighbors in an attempt to climb higher in this short fleeting existence of ours. But at the same time I am not a stone-cold Nihilist that believes that every endeavor in life is pointless. I do concede that there are people out there genuinely trying to make a difference and that some people, regardless of upbringing and circumstance can rise above what is expected of them and become a success. But then I look at the news and see the way the world is and can't help but sigh. We've all had the "I don't want to live on this planet" thought before, and if you look at every major problem the world has, I can assure you it will be man made.
Also, I have never been one to believe that the world is morally ambiguous or "Grey." I find that most simply do not want to make the distinction between what is good and what is not when put on the spot. We should all have a moral compass to live by, even if it is a self constructed one. It gives us a way to look at the world that imbues a sense of purpose and worth that prevents us from giving in to our primal urges to hurt and destroy. Our morality is what separates us from the apes, and without it, we are immoral animals.