As Aristotle says, a tragedy does not have to be focused on character, because characters--individuals who are based on authentic, raw, momentary reactions--are really few and far between. Most of the people of the world get where they are because they are so good at representing what they think is the right thing to do. In other words, most people are relatively empty vessels, waiting to be filled. Easily influenced by the actions of those around them. Some might say "stupid." I would not say "stupid," but I would say these people are not "original." "Original" people are those who are one of a kind, and, quite frankly, there are very few of those, because most people are classifiable and countable.
When you meet a true "original," you know it. They are unclassifiable. Just when you think you know them, they surprise you. They exceed all of your expectations. They defy your judgements. They are not quantifiable or countable. Poor things, they are heavenly things in earthly bodies; it is kind of like they are the bridge between us and the nether world. They are prophets; they are angels; they are devils, too. Them embody larger spirits, and it burdens them throughout their lives.
There are not many originals in this world, but it is quite amazing to witness one at a moment of encounter with a clumsy human experience. They react honestly. If they trip, they trip, and they don't lie about it. If they fart, they fart, and sometimes even apologize. If they laugh, their laugh is infectious; if they cry, the world cries with them. This is why we often make them the performers of the world.
There is, however, a multitude of the ordinary. The ordinary seek out "originals" because they need role models for how to act authentically. Without those role models all they have to go on are other imitators, like themselves.
Sooo, that was the premise behind the justification for Aristotle's tragedy: in tragedy, ethical, original characters must re-present a perfect plot (which is, of course a complete action). It does not matter who the character is who represents that plot, the plot and its lesson will remain the same. And the real point of tragedy - the lesson learned - is the end result of tragedy. Aristotle demands that that lesson be an ethical one. It is most ethical when it is performed by an original character, but one should never forget that it is the action that makes the character ethical.
Indeed, tragedy is fundamentally ethical. And it is ethical because it is very honestly positioned at the juncture of timeless death and the palindrome. Tragedy attempts to teach us an ethical lesson at the time of our encounter with death, so we will continue to live our lives ethically. This, too, justifies the claim that the essence of theatre is ritual, and the essence of ritual is theatre.
Because that is absolutely true.