The discernment between right and wrong engraved on the human conscience can show itself to be deeper and more correct than the content of a norm.
From Theology of the Body, general audience of 8/13/80, “The Content of the Commandment: ‘You Shall Not Commit Adultery'”

As I reread Theology of the Body, I can’t help but catch whole passages, or sometimes just sentences, that are not only wise, but that shed a whole panel of fluorescents on in my mind. The first section of the audiences, which I have almost bumbled my way through, consider the original unity of man and woman. What was it like in the garden? John Paul II explores this, using Scripture.

In this audience, I couldn’t help but stop when I read this sentence. God has equipped us with a conscience for a reason. He has equipped us with the beginning of what we need to make good decisions. All we have to do is let him guide us, and use what he gave us. What society says about ‘right’ and ‘wrong’ is, largely, just an opinion, and often a falsely based one. It has always been that way, from the very beginning of society. John Paul II takes us back to the garden, before the fall, to see what God intended. And it is in studying the intention that I am gaining a deeper appreciation for my own marriage, as God designed it.