374. How is a moral conscience formed to be upright and truthful?An upright and true moral conscience is formed by education and by assimilating the Word of God and the teaching of the Church. It is supported by the gifts of the Holy Spirit and helped by the advice of wise people. Prayer and an examination of conscience can also greatly assist one's moral formation.
Further reading: CCC 1783-1788, 1799-1800375. What norms must conscience always follow?There are three general norms: 1) one may never do evil so that good may result from it: 2) the so-called
Golden Rule, "Whatever you wish that men would do to you, do so to them" (
Matthew 7:12): 3) charity always proceeds by way of respect for one's neighbor and his conscience, even though this does not mean accepting as good something that is objectively evil.
Further reading: CCC 1789
376. Can a moral conscience make erroneous judgments?A person must always obey the certain judgment of his own conscience but he could make erroneous judgments for reasons that may not always exempt him from personal guilt. However, an evil act committed through involuntary ignorance is not imputable to the person, even though the act remains objectively evil. One must therefore work to correct the errors of moral conscience.
Further reading: CCC 1790-1794, 1801-1802