Vatican II puts it simply: "Conscience is what summons us to love good and avoid evil. . . . To obey is the very dignity of the human person, according to it one will be judged. . . . The most secret core and sanctuary . . . along with God whose voice echoes in the depths of the person" (Church in the Modern World).

There is no Hebrew word for conscience in the Old Testament. The Greek word for it occurs only once in Wisdom 17:11. Instead, the Scriptures generally use the word "heart" - "harden not your hearts" (Psalm 95:8). Job insists "my heart does not reproach me."

The Gospels do not use the word "conscience," but one can find this word 25 times in Paul's writings, three times in 1 Peter, and twice in Acts, both times spoken by Paul.

For Paul, conscience is the fundamental awareness of the difference between moral good and evil. "The law is written in our hearts," he says in Romans 2:15.

Several times, Paul appeals to his own clear conscience.

It is the principle of freedom in which moral decisions are made but there must be consideration for the effect of one's actions on others.

In 1 Corinthians, chapters 8 and 10, Paul speaks of the eating of meat sacrificed to idols. One can eat this meat if one's conscience approves it since this is ordinary food as idols are nothing. But, because of this example, a weaker person might eat the meat even though it is against that person's conscience.

So the first person is obliged to refrain from eating it even though in good conscience it could be eaten. Even if the weaker person's conscience is erroneous (believes this meat can't be eaten), still that person is obliged to follow it.

The Church stresses the formation of conscience. Conscience is not formed in a vacuum nor does any one person have enough wisdom and experience to make the decision alone. Conscience needs to be guided and illuminated.

The society in which one lives may help or hinder the development of a right conscience. But Christian influences must be operative also. If one is seriously interested in making a right moral decision, one needs to work at it.

Moral decision-making is a process which requires the individual to sincerely seek a truthful response to a moral question using one's whole being: reason, intuition, senses and feelings.

In a spirit of prayerfulness, openness, prudence and above all honesty, one searches Scripture for the truths found therein, looking to see which side of my moral dilemma is supported by Gospel values.

Then, in the Church's teachings and tradition, a variety of practices and documents will show its principles in regards to the issue at hand.

One also looks at the empirical and social sciences (documented human experience) which might have a bearing on the question to see what they might have to say to help. And one must not neglect to analyze one's personal experiences, circumstances and feelings, as well as the Christian community's experience, to see how this could affect the decision.

St. Ignatius' rules of discernment stress the importance of being in tune with one's inner feelings so that one can discern whether it is the good or evil spirit which is operative.

The overriding questions one needs to ask oneself are: Am I responding to God's call? Is my response life-serving? Will this action help me to become more fully the human person God intended me to be?

Informed by the study of the issue using the relevant resources, a decision is then made based on one's conscience. If one is at peace with the decision and if one had been honest with oneself throughout the process, one can rest assured that it is the right decision. That is what is meant by an informed conscience which one is obliged to follow.

Even should that decision be morally wrong, one is not culpable because every effort was made to determine the right action and one had no intention of breaking the moral law. This is what is called invincible ignorance.

However, I know that people making moral decisions don't always have the time nor the expertise nor the opportunity to do the thorough examination to which I refer. In addition, often decisions are made when one is in emotional turmoil.

But I do not believe that God requires super-human effort. God only expects us to do our best with the gifts and possibilities we have been given. But we need God's grace and the teachings of Scripture and the Church to help us make our decision.