In the same lecture, Ratzinger drew some helpful conclusions about the nature of conscience that speak emphatically to present distortions. Rather than mere subjective, self-centered "infallibility," conscience consists first of anamnesis — a Platonic recollection of real goodness implanted in our being — and second of a deliberate act. Conscience includes both an awareness of man's "essential" being as well as an exercise of his faculties to recognize, bear witness, and judge. It is opposed to "pure praxeology" where "technique becomes the highest criterion."
This is quintessential Cardinal Ratzinger, placing an emphasis on truth as a "middle term" between authority and subjectivity. Real freedom is opposed to relativism, and it allows us to "hear the message of conscience with joy and without fear." This is also why I believe his resignation of the Chair of Peter was such a meaningful and deeply Christian act.
The idea that conscience includes an act, and that it is not simply a habit, is especially timely. Popular morality is more and more focused on "consciousness" that points to "awareness" and "sustainability." The easy criticism of this trend is that relativism has completely won out, and that truth has entirely collapsed into self-referential validation. But consciousness and awareness and sustainability are all positive aspects of anamnesis. In many ways, modern ethical concerns can help to redirect us toward authentic epistemological responsibilities.
A greater error is to omit the active dimension of conscience — our responsibility to recognize, to bear witness, and to judge moral good and evil in very personal circumstances. Consciousness and awareness don't by themselves constitute moral living. This is an error that's easy enough to identify in millennial ethics, but that is just as prevalent among Christians. Thinking and knowing about moral goods doesn't bring them to be, even if they're reflective of a higher, objective, divinely ordered truth. And even worse, failing to engage the active dimension of conscience limits our ability to see that objectivity for what it is. As Ratzinger says, "truth becomes a yoke that is too heavy for our shoulders."
Christian conscience, then, is not a privilege reserved for the elite and intellectual, nor is it a burden imposed from without that is inscrutable and wearying. It is the active acceptance of the fruits of true freedom, formed by careful reflection, and deployed in every instance of mundane life.