Wall Street. That is the root to most evil in the world.
The root of all evil is dichotomy ethics; examples:
"Group A has the right to steal, but group B does not."
"Group A has the right to murder, but group B does not."
"Group A has the right to kidnap, but group B does not."
The effects of this relationship are outlined very well in the
Stanford prison experiment, where people were explicitly divided into these two groups (group A being the prison guards, group B being the prisoners) for a period of time; the experiment had to be called off because the unethical acts of the members of group A became too much for group B to bear. Essentially, group A views group B as less than human, because they no longer are subject to the same rules, just as a lion cannot empathize with a gazelle, just as a serial killer cannot empathize with his victims, just as the people of Nation A cannot empathize with the people of Nation B (because each believe they're a part of group A and believe the other is a part of group B), just as the Nazis could not empathize with the Jews, just as pedophiles cannot empathize with children, just as the men of Wall Street cannot empathize with the "little people", why gang members A cannot empathize with gang members B et al. There is still some form of relationship, but the ethical standards for each group are uneven, leading to increasingly negative consequences depending on how powerful group A is over group B and how strongly each group A fights over dominance.
The perpetuation of this evil is in the act of
doublethink, e.g., "Stealing/killing/kidnapping is evil and unacceptable, but tax/war/prison is a necessary evil and is acceptable," or the belief that dichotomy ethics is "human nature" and therefore just, whilst simultaneously wishing for a better, more civil society. Taking the concepts of theft and taxation under a close eye, we can define each of these the same way: "a compulsory financial contribution." Thus, comparing these two concepts with their meanings: "A compulsory financial contribution is right, but a compulsory financial contribution is wrong." This is clearly contradictory, but such is the condition of doublethink to an unsuspecting individual.
Once again, killing and war can defined equally: "the taking of human lives." Compared: "The taking of human lives is wrong, but the taking of human lives is right." The key difference is, as with the example of theft and taxation, killing is only murder if group B does it without group A's permission, and taking is not theft if group A approves. Behold, dichotomy ethics.
Therefore, if there was one thing about this world I would remove, I would remove a person's ability to believe in multiple contradictory ideas at once. Without dichotomy ethics, we are left with this:
"People have no right to steal."
"People have no right to murder."
"People have no right to kidnap."
Consistency and sanity. Doesn't mean people won't steal, murder or kidnap, but at least they'll be acknowledged as the evil they are and cannot worm their way out of punishment through an equally evil system, which fails to exist without the dichotomy.