Trollope is no feminist; he generally seems interested in feminism only insofar as it provides expedient plot devices and characters to lampoon. Nonetheless, I think He Knew He Was Right is clearly about how the expectation of patriarchal power drives men insane, and this makes open, direct relations between the genders more or less impossible. Trollope even changed the title from “Mr. Trevelyan" to He Knew He Was Right, to emphasize the thematic concern of epistemic male stubbornness and egoism. (Though Trollope may have been unhappy with the ring of his made-up name; my favorite line in the book is when one of the traveling American women says, ”Mr. Trevelyan! What a pretty name. It sounds like a novel.“)
When Louis, who under the pretext of jealousy has made extreme demands of submission and obedience from his wife, is in his Italian hideaway with his son, whom he has abducted and carried off to the continent, he is confronted by his wife’s father, who means to defend her honor against Louis’s claim that she was somehow responsible for his misery. Everyone in the novel thinks Louis has gone "mad” because he is stuck on insisting complete authority over his wife, demanding she take responsibility and apologize for the jealous thoughts he has had, even though they are paranoid at best and at worst just an arbitrary reason for him to exert his dominance over his wife.
But that is not insane so much as it is the logical conclusion of patriarchal authority. That authority is such that she is totally responsible for his feelings, whatever they are, and accountable for them, while he is in no way responsible for her feelings, which it is her duty to control and make pleasing. He chooses to tell everyone about his wife’s “sin” and her “falseness” and her “being untrue,” all of which are readily interpreted as unfounded claims of her sexual infidelity, which prompts her father to make an outraged defense of his child. Trevelyan responds,
“Your child, sir! She is my wife;—my wife;—my wife!” Trevelyan, as he spoke, advanced close up to his father-in-law; and at last hissed out his words, with his lips close to Sir Marmaduke’s face. “Your right in her is gone, sir. She is mine,—mine,—mine!”
She is a piece of property, first and foremost, of course, but that has affective connotations as well as material ones. Only Louis has the “right” to be emotionally affected by her behavior; he controls and covets any emotional resonance she has in the world. What is matrimonial obedience worth, after all, if it has an affective horizon? If it doesn’t make a man more but less emotionally secure?
Later, his wife goes to see him and tries to persuade him that she still loves him, even after all his intransigence. He is tempted, but then this:
He shook his head, and began to think,—while she still clung to him. He was quite sure that her father and mother had intended to bring a mad doctor down upon him, and he knew that his wife was in her mother’s hands. Should he yield to her now,—should he make her any promise,—might not the result be that he would be shut up in dark rooms, robbed of his liberty, robbed of what he loved better than his liberty,—his power as a man. She would thus get the better of him and take the child, and the world would say that in this contest between him and her he had been the sinning one, and she the one against whom the sin had been done. It was the chief object of his mind, the one thing for which he was eager, that this should never come to pass. Let it once be conceded to him from all sides that he had been right, and then she might do with him almost as she willed. He knew well that he was ill.
He can only think of a marriage as a power struggle — sexual jealousy is explicitly irrelevant to this novel, which is part of what makes it so devastating a portrait of patriarchal power. The other characters in the novel think all that stuff about honor and a woman’s good name are basically euphemistic for sexual integrity, but it’s actually that control over sexuality is a pretense for total emotional control. This emotional control has nothing to do with sexual passion, though it’s hard for us moderns, who equate those two things, to recognize that.
His power as a man is contingent not on liberty but a constrained relation to a woman/slave, which he regards as “better.” The object of this total patriarchal power is not even the wife in the end, but the audience for their power struggle, patriarchal society, which has made a sport of watching couples struggle with integrating companionate marriage with longstanding hierarchies. Louis doesn’t want to control his wife but public opinion about his reputation, which hinges on the impossible standard of no one thinking anything inappropriate about his wife or the way he chooses to treat her.