Trevin Wax writes in Counterfeit Gospels (page 117-18) about the human drive for moral standards, as well as the deep-seated tendency to justify ourselves by those standards...
In Policy Review, Mary Eberstadt compares two imaginary ladies, a grandmother named Betty and her thirty-year-old granddaughter, Jennifer. Betty wouldn’t think of judging someone based upon what they eat. Jennifer wouldn’t think of judging someone based upon their sexual activity. But both still maintain some notion that there is right and wrong.
What the imaginary examples of Betty and [her thirty-year-old granddaughter] Jennifer have established is this: Their personal moral relationships toward food and toward sex are just about perfectly reversed. Betty does care about nutrition and food, but it doesn’t occur to her to extend her opinions to a moral judgment—i.e., to believe that other people ought to do as she does in the matter of food, and that they are wrong if they don’t. In fact, she thinks such an extension would be wrong in a different way; it would be impolite, needlessly judgmental, simply not done.
Jennifer, similarly, does care to some limited degree about what other people do about sex; but it seldom occurs to her to extend her opinions to a moral judgment. In fact, she thinks such an extension would be wrong in a different way—because it would be impolite, needlessly judgmental, simply not done. On the other hand, Jennifer is genuinely certain that her opinions about food are not only nutritionally correct, but also, in some deep, meaningful sense, morally correct—i.e., she feels that others ought to do something like what she does.
And Betty, on the other hand, feels exactly the same way about what she calls sexual morality.
Do you see how the desire to judge is woven into the core of our being? Generations may trade morals and values, but all of us long for universal morality. We are born to be moralists.
God has given us a conscience that reveals to us that something is wrong with the world. Likewise, deep down we know that something is wrong with us.
Moralism satisfies our desire for a universal morality in a perverse way. We look for ways to define our morality based upon whatever is socially acceptable. By shifting with the moral standards of society, we feel good about staying within current expressions of morality and rejecting older expressions of morality. Ironically, what may look like license is actually a commitment to new moral norms.