In The Lives of Others Wiesler begins the film as a committed Stasi man, even conducting classes for new secret police recruits about interrogation methods but cracks begin to form in his worldview as he immerses himself in the lives of the artists he is spying on. The sterility of his own overly fastidious life is highlighted as he discovers the richness in the world of the Dreyman and Christa Maria.
Donnersmarck has said about the transformation of Wiesler, “It’s not specifically just that relationship. In all these screenplay books I read, they always said you need a specific turning point for the character. I’m always weary when people swing around in their political directions. People change when there’s a continuous crisis. It’s many things that push you in the same direction. On one hand, he realises that his friend, who was always a little less intelligent and a little less loyal, is actually having a more successful career than he is. He also sees that something as sacred as a mission to uncover an enemy of the state is used to satisfy a high party functionary’s testosterone level. This is not what he signed up for.
On the other hand, he realises these enemies of the state are normal people with problems, kindness, pettiness, and everything else. Then there’s the additional factor of him experiencing art, poetry, and music in a way he never has before. It’s all of that together, throughout the entire film, that makes him an almost-accidental hero. He’s not your knight in shining armour who fights for good.”