Both Bayard and Horace are morally weak characters, but it is inaccurate to call their actions a "moral decline." In reality they are only perpetuating the morally flawed system from which they came. The difference is that the glossy exterior of aristocratic society invented in Colonel Sartoris' day to justify an immoral system, has begun to wear thin. The immorality of these aristocratic frauds has been exposed by a new society where the caste system has to a great extent broken down. Reduced to the role of figure head of a dead era, or shown to be pathetic actors in a pseudo-aristocratic farce, the progeny of the old tradition have become a joke. Bayard seems to sense this, Horace appears oblivious to it, but they both become self-destructive because of it. Failing to adjust to the reality of their surroundings, they both pay dearly for it--one with a senseless death, the other with a profound unhappiness (the marriage to Belle). In the end it is not a moral decline, but rather an exposure of a magnolia and wistaria laden continuum of immorality.