MANDERS. Well, I mean people in such independent and influential positions that one cannot help attaching some weight to their opinions. (1.209)
As a provincial clergyman, Manders has social, political and business duties. Preserving his reputation among the who's who is important to preserving his welfare.
MANDERS. Now, as I have been your adviser, and have had the business arrangements in my hands, I cannot but fear that I may have to bear the brunt of fanaticism – MRS. ALVING. Oh, you mustn't run the risk of that. MANDERS. To say nothing of the attacks that would assuredly be made upon me in certain papers and periodicals, which – (1.215-217)
Manders brings up his personal reputation as the last support for the argument against insuring the orphanage. It's the closest to his heart, and also the most convincing for Mrs. Alving, who cares about him.
OSWALD. And yet he managed to do so much in the world; so much that was good and useful; although he died so early. (1.295)
Almost wholly informed about his father through his mother's deceptive letters, Oswald has an image of his father as a charitable nobleman.
MANDERS. Yes, you have inherited the name of an energetic and admirable man, my dear Oswald Alving. No doubt it will be an incentive to you – (1.296)
During this part of the conversation, Mrs. Alving is silently listening. It rankles her to hear Manders (the man she once loved) and Oswald glorifying the man who made her miserable. Now, however, is not the time to talk about it.
MRS. ALVING. Here, in my loneliness, I have come to the same way of thinking, Pastor Manders. But I have never dared to say anything. Well! now my boy shall speak for me. (1.351)
Mrs. Alving is courageous in her thinking, but not so much in her actions. Still insecure about her own progressive values, she looks to Oswald to support and articulate them.
MANDERS. But instead of that you rebelliously throw away the cross, desert the backslider whom you should have supported, go and risk your good name and reputation, and – nearly succeed in ruining other people's reputation into the bargain. (1.360)
Ah-ha! So that's where you were going with that, Manders. Pastor Manders spends a lot of time condemning Mrs. Alving in idealistic, general, religious terms. Behind the sermon lies a very personal fear of exposure and humiliation.
MRS. ALVING. Other people's? One other person's, you mean. (1.361)
Mrs. Alving immediately recognizes Pastor Manders's Achilles heel: his fear of public condemnation. She calls him a "big baby," and part of her wants to protect him. Why else would she agree not to insure the orphanage?
MRS. ALVING. And you know what power Alving had of winning people's hearts. Nobody seemed able to believe anything but good of him. He was one of those people whose life does not bite upon their reputation. (1.399)
In his joy-of-lifey way, Captain Alving charmed the neighbors who may otherwise have thought badly of him. We can just imagine the couple at a party: he's the fun one, she's serious.
ENGSTRAND. And to think that such a thing should happen to a benevolent Institution, that was to have been a blessing both to town and country, as the saying goes! The newspapers won't be for handling your Reverence very gently, I expect. (3.36)
And the wily carpenter sticks his finger right into Pastor Manders's open wound. Like Mrs. Alving, Engstrand recognizes that the Pastor fears public humiliation above all else. Unlike Mrs. Alving, he uses that knowledge to secure his own stability.
REGINA. [To herself.] So mother was that kind of woman. (3.133)
While she defended her mother violently in the first scene with Engstrand, Regina doesn't throw a fit when she finds out his intimations were true. Regina is pragmatic. There's not point in making a fuss now, she just needs to figure out what's next.