Some say: Ignorance is bliss, because it excuses them to do what really want to do. Yet only invincible ignorance of a person who has no possibility of knowing the morality of an act excuses. Such ignorance is common among small children and very uneducated people.

If… the ignorance is invincible, or the moral subject is not responsible for his erroneous judgment, the evil committed by the person cannot be imputed to him. It remains no less an evil, a privation, a disorder. One must therefore work to correct the errors of moral conscience (CCC 1793).

Suppose an engineer said ignorance is bliss, designing a beautiful bridge that everyone acclaims. Yet the bridge collapses during an earthquake, taking many lives. In the enquiry after the disaster, the investigators discover that the engineer failed to do a seismic study of his design before building the bridge—he just didn’t know how to do seismic studies. Would everyone excuse him for his ignorance? Certainly not: it was his job to know, or at least to hire a consultant to do the seismic study. The same is true about doctors diagnosing our illnesses: it is their job to know. Thus our Lord encourages us to build our moral lives on a good foundation:

Every one then who hears these words of mine and does them will be like a wise man who built his house upon rock; and the rain fell,and the floods came, and the winds blew and beat upon that house, but it did not fall, because it had been founded on the rock. And every one who hears these words of mine and does not do them will be like a foolish man who built his house upon sand; and the rain fell, and the floods came, and the winds blew and beat against that house, and it fell; and great was its fall (Matthew 7:24-27).

Having freedom to make moral decisions obliges us to follow our conscience enlightened and formed by truth. God enlightens the conscience through that formation. As Jesus says: “If you continue in my word, you are truly my disciples, and you will know the truth, and the truth will make you free” (John 8:31-32).

Overcoming Ignorance and Bad Formation

Ignorance, and poor and unreliable formation, causes serious errors and harm:

Ignorance of Christ and his Gospel, bad example given by others, enslavement to one’s passions, assertion of a mistaken notion of autonomy of conscience, rejection of the Church’s authority and her teaching, lack of conversion and of charity: these can be at the source of errors of judgment in moral conduct (CCC 1792).

If a person is not responsible for his erroneous judgment, the person does not bear the guilt of the evil act. Yet the act itself remains evil, and the person eventually must confront the evil and take responsibility for his acts.

For example, there was a handsome young college student who had been a good athlete in high school. His father taught him that the way you deal with women is to conquer them. This he did throughout high school and college. One day this student met a girl who was—as he described her—beautiful on the inside as well as on the outside. He realized that if he were to conquer this girl he would destroy her beauty. It was at that moment that he fully discovered the erroneous formation he had received. He began to rediscover and study his faith, which totally changed his life; he learned the freedom of true love.