Thomas Aquinas

"[Thomas Aquinas] is clear that in a conflict between authority and conscience, it is conscience that we are to follow. Conscience may turn out to be mistaken. It may even turn out that our sin and stubbornness have distorted our conscience, so that it is our own fault when conscience gives us the wrong answer. Still, the right thing to do is what conscience tells us. Bad judgments will need to be corrected, and if we have contributed to them by our own sin, we may expect punishment for it at some later point, but we must not obey anyone who tells us to go against what our conscience tells us now."

— Robin W. Lovin in An Introduction to Christian Ethics: Goals, Duties, and Virtues