NORA: "A barrister's profession is such an uncertain thing, especially if he won't undertake unsavoury cases; and naturally Torvald has never been willing to do that." (1.114)
Does Torvald's dedication to obeying the law stem from personal integrity or a fear of what other people might think?
KROGSTAD: "My sons are growing up; for their sake I must try and win back as much respect as I can in the town. This post in the Bank was like the first step up for me—and now your husband is going to kick me downstairs again into the mud." (1.358)
Regaining his good name is Krogstad's major motivating force throughout the entire play.
NORA: "Your squirrel would run about and do all her tricks if you would be nice, and do what she wants." (2.92)
Does Nora respect herself when she resorts to these kinds of tactics?
NORA: "Yes—yes, of course. Just recall to your mind what these malicious creatures wrote in the papers about papa, and how horribly they slandered him." (2.108)
It seems Nora's family has a history of scandal.
HELMER: "I hear [Krogstad] is a good worker, too. But I knew him when we were boys. […] this tactless fellow lays no restraint on himself when other people are present. On the contrary, he thinks it gives him the right to adopt a familiar tone with me." (2.117)
Here's the real reason Helmer is firing Krogstad: once again he's worried about his reputation.
HELMER: "Your father's reputation as a public official was not above suspicion. Mine is." (2.109)
Helmer seems to base a lot of his self worth on what other people think about him.
HELMER: "Do you suppose I am going to make myself ridiculous before my whole staff, to let people think that I am a man to be swayed by all sorts of outside influence?" (2.113)
The influence that Torvald is referring to here is his wife. He's afraid to seem weak in public.
KROGSTAD: "I will tell you. I want to rehabilitate myself, Mrs. Helmer; I want to get on; and in that your husband must help me." (2.283)
It's ironic that Krogstad wants to fix his seedy reputation by blackmailing someone.
HELMER: "I must try and appease [Krogstad] some way or another. The matter must be hushed up at any cost." (3.242)
Krogstad was right when he predicted earlier in the play that Torvald would submit to his demands. The crooked lawyer knows his old friend has always been obsessed with what other people think.
Mrs. Christine Linde
MRS. LINDE: "Nils, I have faith in your real character—I can dare anything together with you." (3.58)
Christine doesn't care about what people say. She stands in stark contrast to Torvald and Krogstad, who are obsessed with reputation.