What is the theme in The Master Builder by Henrik Ibsen?

Self-Deception
Solness is aware of the suffering he has caused others, especially his wife, during his self-serving rise to power. In an effort to cope with the harsh consequences of this unchecked ambition, he tries to convince himself that he has not been completely responsible for his actions. He struggles to persuade others, as well as himself, that he is beset by internal devils, ‘‘players’’ that impose his will on others, without his consent. Solness insists that all he has to do is think of something he desires and immediately with no instruction from him, his devils carry out the deed. For example, the first time he meets Kaja, he thinks that he would like her to work in his office so Ragnar ‘‘would stay put too.’’ As he is telling this story to Dr. Herdal, he swears he ‘‘didn’t breathe a word’’ of these thoughts to anyone, but the next day, Kaja came back to the office, acting as if he had already given her the job. As a result of these thoughts, Solness admits to the doctor that he fears that he is going mad.

Hilda reinforces this self-deception when she insists that she also has a troll inside of her and that the trolls in each of them have brought them together. By absolving them of the responsibility of their desire for each other and their plans to run off together, Hilda tries to assuage their guilt over destroying Solness’s marriage and abandoning Aline.

Age versus Youth
As Solness struggles to cope with the consequences of his actions