Human Nature, apparently, craves a morality. The Church has insistently offered and prescribed a moral system to the People of God.
It is not always noticed that when HWHY delivered a code of morality, Ten Words, to Moses for the People of Israel, He did so in the singular: "Thou shall ... Thou shalt not."
This 'singular' aspect of Morality is essential. I will not say that it is the whole of the story. Most of the Torah is in the plural, addressed to the People. Perhaps some readers will not share my approval of certain aspects and expressions in Liberation Theology, but I am quite sure that Sin is embodied in immoral corporate structures. And in those corporate structures Sin is indeed to be resisted. The doctrine of Original Sin expresses the truth that our Sin is a Corporate, species-wide, Sin; inherent in what it is to be a Son of Adam or a Daughter of Eve.
But any morality which excludes individual obligation is phony. Which is why we must resist the modern tendency to down-play individual Sin and to elevate the corporate aspects of Sin so high as to obscure individual responsibilities.
Quite possibly, in a culture which emphasised, as 'Victorian Morality' perhaps did, the lapses (particularly sexual) of individuals, Christian witness obliged us principally to condemn corporate structures of Sin. But such a situation, if it existed, is now reversed.
So, among other things, I am talking critically about a culture which ignores the precepts of the Decalogue, addressed to each individual, and lays great emphasis on corporate Sin. In our own day, Thou shalt not kill is ignored when it is matter of the life of one inconvenient child in the womb of one inconvenienced mother, but a genocide happening thousands of miles away, or two or three generations ago, is a matter of great moment and of self-righteous moral posturing.
Thou shalt not commit adultery is reduced to very small proportions by a prescribed obligation to demonstrate against Global Warming. And what is left of it is demolished by emphasis on the newly-minted 'Sin' of failing in Inclusivity and Diversity and Non-judgementalism.
It is only if my feet are firmly planted on my obligation not to kill or to commit adultery, that I have any locus standi to say to my fellows "We must do, or must not do, such-and-such".
To be concluded.