On one extreme in terms of morality, people who are perceived as pure evil include Adolf Hitler, Mao Zedong, Osama Bin Laden, and Ivan the Terrible.  All of these people were responsible for the deaths and suffering of thousands of people.

 Every man listed was a terrible person, but were they pure evil?   Can you truly say that every inch of these men's brains was evil, and nothing but?  Adolf Hitler promoted anti-smoking advertisements and was a vegetarian most of his life; Mao Zedong campaigned for women's rights and set them to a higher standard.  These men were bad, but can you really say confidently that they were all evil and had no redeeming qualities?

On the other side of morality, notoriously good people include Mohandas Gandhi, Martin Luther King Junior, and Abraham Lincoln.  These people did great things that helped thousands.

 These people may not have been the saints you envision them to be.  Mohandas Gandhi was a well-documented misogynist; he may have stunted India when it came to women's rights.  Alongside this, Abraham Lincoln heavily censored anti-union papers.  So, from these examples, you can see that though they did great things, they weren't perfect human beings, because to be human is to be imperfect.

Various pieces of fiction depict good and evil, but one of the most interesting takes is the duality of man.  Examples include Fight Club and The Strange Case of Dr Jekyll and Mr Hyde.  We'll go over the latter by Robert Louis Stevenson: Henry Jekyll was a stand-up British gentleman; by all means, he represented the good in the world.  

In contrast to him, the Evil Edward Hyde seeks to do only things that give him pleasure, with no regard for others or even for his own future.  Later in the novel, it is revealed that Doctor Jekyll is Mr Hyde; they are the same person.  It is also revealed that Jekyll may not be the perfect encapsulation of morality that he was set up to be, and that Mr Hyde is his responsibility.

In short, despite Henry and Edward being the representations of each end of morality, both sides have a bit of each other inside of them somewhere; it may be hidden, but it's somewhere.

Our minds are wondrous machines, and their different aspects contribute to today's topic.  As one of Sigmund Freuds somehow less questionable theories, the Id, Ego and Superego attempt to explain the different aspects of human psychology.  The Id represents our primal desires, such as lust, rage, and other temporary pleasures.  The Ego is essentially our logic and reasoning, and acts as a midpoint between the Id and Superego.  Finally, the Superego is our conscience, giving us morality and our code; this is usually the last one to develop.

Philosophy is a big part of our society and can be found as far back as ancient Greece.  Nietzsche discussed the dynamic between the Greek god Apollo and Dionysus.  One is portrayed as a paragon of morality, and the other is driven by simple and harmful desires.  Carl Jung also wrote about something called the "Shadow Self", a representation of the parts of ourselves that we repress and don't show to the outside world.  One must be careful to not let their shadow overwhelm them, if that happens they will merely be a puppet for said shadow.  Who's to say who is a victim of their unconscious and who's not?