Nora: (goes over to the table, right) You know I could never act against your wishes.
Torvald: Of course not. And you’ve given me your word -

Nora declares her faithfulness to Torvald’s preferences when he teases her about violating his prohibition on eating sweets. While her dishonesty regarding the pastry she has just secretly eaten is not serious, this scenario reveals how easily Nora lies. Nora reassures Torvald that she would never go against his wishes, which we later find out is not the truth.

This secret that is my pride and my joy – that he should hear about it in such a filthy, beastly way – hear about it from you! It’d involve me in the most dreadful unpleasantness -

Nora responds with disgust and indignation to Krogstad’s threat to reveal that she borrowed money from him for Torvald. Although Nora knows she would face Torvald’s anger if he found out about the loan, she still feels satisfaction in the transaction. Such feelings reveal Nora’s sense of power while engaging in deceit, the only feeling of power she has in her marriage. Despite her struggle to repay the money, Nora feels proud of what she was able to do for her family, even if she was only able to get away with it by lying.

Just think how a man with that load on his conscience must always be lying and cheating and dissembling – how he must wear a mask even in the presence of those who are dearest to him, even his own wife and children!... Because an atmosphere of lies contaminates and poisons every corner of the home. Every breath that the children draw in such a house contains the germs of evil.

After Torvald tells Nora that Krogstad forged someone else’s name, he explains how such an action destroyed Krogstad. The audience is aware that Nora’s crime is the same as Krogstad’s, and in trying to cover up her crime, she too has had to lie to those dearest to her. Unlike Torvald’s description of Krogstad, rather than feeling guilt over her dishonesty, Nora felt justified in her actions. The irony of Torvald’s observation is in his unwillingness to look more closely into people’s motives: In Torvald’s description of the fallout from lying, he is demonizing a liar rather than empathizing with a person who may have extenuating circumstances.