King Lear is one of the world’s most brilliant insights into the weaknesses of a human being. The main theme of Shakespeare’s tragedy is the corruption of the human soul by the unlimited power and authority and self-destruction, which results from it.
At the beginning of the play Lear is a person whose inborn dignity has already been fully destroyed by the enormous power he possesses. He is so self-confident and arrogant that he refuses from his throne, being perfectly sure that he will be highly respected without his crown and land. However, he discovers that he has made a horrible mistake. It comes as revelation to him that in the corrupted human society a person is not important for his/her personal qualities. What really makes the difference in the attitude to the person is the wealth and title he/she has. The one who is not mighty or rich is worthless and rejected. And this is the kind of attitude he has to accept.
Having realized that all his previous ideas were wrong, Lear loses his mind and, being totally insane, he suddenly discovers a new feeling: he starts sympathizing and feeling compassionate to all people in misery. But it is too late, as he himself has already given the cruel and the wicked too much power. His loyal and kind daughter Cordelia, the embodiment of love and virtue, dies, and having lost her, Lear loses interest in life. Nevertheless, the wicked die as well. The vanity and selfishness kills them too. So, the whole family is destroyed.
The tragedy focuses on the idea that evil cannot be controlled. Those who bring it to life will inevitably die, but it can also destroy the innocent, as the stream of life makes no difference between people and that is why every single person bears full responsibility for his/her actions.