Henrik Ibsen, in A Doll's House, explores the limiting and, sometimes debilitating, impact of social "norms" and the need of some to behave in a certain way, even when it negatively affects their lives.
Torvald clearly maintains his position of authority in the household. He mistakenly believes that his control will ensure that his family not only maintain a certain standard but that it meets social expectations and is successful. Nora and Torvald's position in the family hierachy is revealed to the audience almost immediately as Torvald reprimands his "little spendthrift" and talks to her like a child " Don't interrupt me." (Act I). Torvald does not think that his wife can make any valuable contribution to anything other than domestic affairs and the children.
He is particularly influenced by a belief that children are predisposed to suffer as a result of their parents' characteristics and even their shortcomings or indiscretions. Whilst accusing Nora of overspending he reveals " It's in the blood. Yes, Nora, that sort of thing is hereditary." (Act I) Torvald's tight hold of the family budget is partially to protect her from herself as in his opinion she could never manage without him. It is his responsibility to ensure the family is provided for as, if his brains were "knocked out," there is a belief that, without his pre-planning, she would not manage.
The fact that Torvald has no idea about Nora's secret, the loan she took out when Torvald's life was threatened, presumably by stress, reinforces his belief that the family revolves around him. It comes as such a shock to him when all is revealed that his reaction causes Nora to reassess her own circumstances and realise that Torvald's love is paternal only, a feeling of duty driving his actions rather than his love for Nora.
It is then, Torvald's sexist attitude that ultimately drives them apart as he is unable to reconcile his beliefs with the reality that faces him. Even if he is initially angry with Nora for keeping this secret, his reaction when he discovers it reveals only his sexism as he does not think Nora should have ever done such a thing - it's just not right "Are you not clear about your place in your own home ?" (Act III) - and he is offended by the suggestion that he could not provide. He feels no relief that his burden of responsibility is shared nor that he now has an equal partnership with Nora. "I almost think you are out of your senses."
Torvald only feels betrayed, much as a parent feels when a child disappoints him or her. Torvald even questions Nora's religious beliefs. The final straw comes as "no man sacrifices his honour, even for one he loves." Nora realises that Torvald only loves to look after her when she is supposedly "so weak and fragile" and his restricted, sexist view has now caused the end of their relationship due to his failure to accept Nora's new found independent spirit.