A Clockwork Orange
Alexander DeLarge is the devil.
We see in the movie that he's an irredeemable monster. He cares for no one. He attacks and assaults as he pleases, whether you're young or old, male or female, or friend and foe. He exists only to fulfill his desires, only to please himself, to do whatever he wants without regard for others as long as it helps him in some way.
He corrupts everything he interacts with, making Beethoven something that invigorates him and milk something that fuels him for his ultra violence, making things as sacred like sex, vulgar and heinous.
His relation to the devil is even shown in the movie, such as how he keeps and loves his snake, Basil, representing Satan and the snake which tempted Eve, especially when the snake rises above the figures of Jesus and reaches for the woman on the wall. At one point in the movie, Alex even envisions himself with Christ, not as a believer, but as one of the people who whipped and beat him.
This all goes to show who Alex is. There's no reason for him to be like this. His parents loved him, he had a nice apartment and was smart enough where he could have excelled in school. Alex is Alex because he just is. He is the very embodiment of free will, of someone who acts on his own impulses, who would never care about how other's feel or think, someone anyone would despise.
This makes him the perfect protagonist of this film, the perfect victim of the Ludovico procedure, a procedure that alters a person's mind and rips them of all individuality and free will.
Kubrick makes it clear that the point of this movie is not to answer whether the Ludovico procedure is right or not or if people should have free will or not. Instead, the movie gives you perspectives on both sides.
We see what Alex does to other people, we see how much people hate him and we learn to feel the same way. Alex is not meant to be a likeable character. Yet at the same time we see the consequences of the Ludovico procedure, and how much it hurts and pains Alex, torturing him by making him hate and grow sick of what he loves, even if it's something despicable. By putting us in Alex's position, we see the negatives of the procedure itself, how it is practically torture to rob humans of their most basic and important right, that being free will. At the same time we know Alex is a monster, we know that this prevents the harm he can do to everyone around him.
Yet the government isn't innocent either. The Minister of the Interior states at the beginning of the film that the whole purpose of the Ludovico procedure is to get rid of all the criminals from the prison and to instead keep political prisoners, people they've arrested for opposing them, for having different beliefs than them. The government may transform and control people through the Ludovico procedure, yet they don't hold themselves accountable. What is to stop them from eventually using the procedure to condition people to obey them, to not rebel, to forcefully change their beliefs?
If Alex is the devil, the government plays the role of God, having control over and defeating the devil. Yet humans aren't meant to play this role. All humans are born with the inherent right to free will, to do what they want, and to infringe on such a fundamental right is placing them on the position of God, with the ability to control and manipulate anyone, power no human should have.
There is plenty amount of ways to argue both sides from this movie, which is what makes this movie so great and showcases Kubrick's feats as a director.