Archbishop Harry Flynn affirmed this in a pastoral letter released Monday, titled "Moral Conscience." Archbishop Flynn retired May 2, upon turning 75.
In the letter's first section, the prelate suggested that the novelty of today's understanding of right and wrong is that "now the very idea of knowing right and wrong is called into question."
"This questioning of the truth of right and wrong, the questioning even of the possibility of knowing anything to be certain," he explained, "leads to what we call 'relativism.' It has been creeping up on us for centuries, gradually changing the way we think about ourselves and our world."
Archbishop Flynn noted how relativism works: "This sort of subjectivism leads to the notion that things are good or bad because they do or do not suit my preferences, because they are or are not in accord with what I think is best for me -- almost like deciding what sort of car to drive or what sort of music to enjoy. Of course, preferences have a valid part to play in our lives, but mere self-centered choices will never serve as a basis for true fulfillment or as a way of serving the common good."
The prelate then turned his attention to the role of truth in the moral life.
"Truth is essential in our relationship to God and to each other," he said. "The foolishness of what we have referred to as relativism is in the fact that it tries to accept everything as possibly true and ends up accepting nothing as actually true."
"God has given us the means of finding the truth," Archbishop Flynn continued. "He has given us faith and reason, and they are both his gifts, they are both of value in our search for truth, our search for God. Far from denigrating the power of human reason, the Church has consistently defended it. It has seen no contradiction between reason and faith, but has recognized their ordered relationship.
"Reason’s search for truth is not wrong, it is simply not fully sufficient in itself. It finds its fulfillment in the act of faith."
The archbishop noted, "True freedom is not, as we are sometimes prone to think, the possibility of choosing either good or evil. The possibility of choosing evil is actually a perversion of freedom. True freedom is the possibility of always being able to choose what is truly good, and that we can do only if we come to know the truth about what is right and what is wrong. Know the truth, and the truth will truly set you free."
Thus, he explained, "there is no contradiction between a Church that offers the love of Christ and a Church that teaches the truth which Christ embodies."
With that backdrop, the prelate turned to the role of conscience.
"Conscience measures a contemplated act against the objective standard of the moral law, which is one aspect of the truth that sets us free and to which the Church bears witness. Conscience applies this law of love in the particular circumstances of daily life," he said.
"In other words," Archbishop Flynn continued, "conscience does not determine what is right or wrong, but rather makes a judgment about whether a particular proposed action is in accord with what is right or wrong and is, therefore, a good or evil action."
From that, it is clear that conscience, as a human judgment, can be wrong, the archbishop said.
"This is why the Church teaches that conscience must be properly formed," he noted. "Clearly a person must follow conscience in order to be morally responsible. Yet no human being can realistically claim that his conscience is simply infallible, since decisions of conscience depend on conformity to the objective moral law and do not create the moral law. But if conscience can be erroneous, therein lies the potential for tragedy.
After explaining the importance of conscience formation, the archbishop affirmed: "To have a well formed conscience is not to have our freedom constrained. It is, rather, to have a freedom that is full and complete, because in every choice made on the ground of a well formed conscience we come one step nearer to God and one step nearer to what, in our heart of hearts, we truly wish to be."
"To live in Christ is to live as another Christ," Archbishop Flynn concluded. "It is to live for the truth and to lay down our lives for that truth as witnesses to the gift we have received. To live in Christ is to love self and neighbor as does Christ.
"This love is not a feeling. It is a steadfast willing. It is a constant choice of the good, and that good must be illuminated by the truth known to reason and fulfilled in faith. This is the function of the well formed conscience. It is a responsibility of the highest order. It is something we must all pursue, for without a conscience informed by the truth we can never find fulfillment in the love of God or love of neighbor."