THANK YOU FOR THE QUESTION, I LIKE GETTING TO GO INTO IT. In short Harvey's intense Madonna-Whore Complex is the central pillar of how he perceives and interacts with all women. He divides the female sex into two rigid, irreconcilable categories: the pure, respectable Madonna and the degraded, disposable Whore, as the complex dictates. There is almost no gray area for him.

Loretta, initially, is the the embodiment of the Madonna in Harvey’s life. She represents the ideal of the quiet, mousy, grieving widow who became a devoted suburban wife and mother. In his mind, she is meant to be modest, dutiful, and sexually restrained; outwardly symbolizing proper middle-class WASP femininity. He needs her to remain pure and submissive to preserve his fragile self-image as a respectable family man. Sex with her is rare, mechanical, and often leaves him feeling resentful or impotent afterward, because domestic intimacy feels like obligation rather than conquest. At the same time, he secretly resents her for "trapping" him in this respectable life and fantasizes about her betraying him, which would finally give him justification to punish her as the whore he suspects all women truly are.

In contrast, the prostitutes and sex workers he frequents in the city are pure Whores to him. These women—often wearing fishnets, cheap perfume, and revealing clothing—embody unthinkable open sexuality and moral corruption in his eyes. Their existence offends his sense of dated 1950s decency, yet that very offensiveness is what arouses him. He views them as disposable outlets for his rage, violence, and sexual frustration. They are beneath contempt, objects to be used and discarded. Once he penetrates them, they become his permanent property. Any assertion of independence is seen as betrayal, which justifies his brutal violence.

The deepest tension and excitement for Harvey lies in the space between these two poles. He is most aroused by the fantasy of corrupting a Madonna i.e. slowly eroding the boundaries of a prim housewife, secretary, or respectable mother, turning her "trashy," and then punishing her for the fall. This is why he spies on neighboring housewives, makes obscene phone calls, and engineers situations where women of the street belittle him: it gives him the moral excuse to unleash his rage. Homemakers are outwardly to be respected and protected, but secretly lusted after as future victims. Sex workers, while useful, ultimately feel less satisfying because they lack the delicious drama of a fall from grace, which warrants their immediate disposal.

Through Harvey's eyes, all women are ultimately whores: the Madonna is simply one who hasn't been properly exposed yet. His violence is, at its core, punishment for this perceived universal female deceit and betrayal of the idealized feminine nuclear family role he both worships and desperately wants to conquer.