Dominum et Vivificantem §43

⁴³ The Second Vatican Council mentioned the Catholic teaching on conscience when it spoke about man's vocation and in particular about the dignity of the human person. It is precisely the conscience in particular which determines this dignity. For the conscience is "the most secret core and sanctuary of a man, where he is alone with God, whose voice echoes in his depths." It "can ...speak to his heart more specifically: do this, shun that." This capacity to command what is good and to forbid evil, placed in man by the Creator, is the main characteristic of the personal subject. But at the same time, "in the depths of his conscience, man detects a law which he does not impose upon himself, but which holds him to obedience." The conscience therefore is not an independent and exclusive capacity to decide what is good and what is evil. Rather there is profoundly imprinted upon it a principle of obedience vis-a-vis the objective norm which establishes and conditions the correspondence of its decisions with the commands and prohibitions which are at the basis of human behavior, as from the passage of the Book of Genesis which we have already considered. Precisely in this sense the conscience is the "secret sanctuary" in which "God's voice echoes." The conscience is "the voice of God," even when man recognizes in it nothing more than the principle of the moral order which it is not humanly possible to doubt, even without any direct reference to the Creator. It is precisely in reference to this that the conscience always finds its foundation and justification. The Gospel's "convincing concerning sin" under the influence of the Spirit of truth can be accomplished in man in no other way except through the conscience. If the conscience is upright, it serves "to resolve according to truth the moral problems which arise both in the life of individuals and from social relationships"; then "persons and groups turn aside from blind choice and try to be guided by the objective standards of moral conduct." A result of an upright conscience is, first of all, to call good and evil by their proper name, as we read in the same Pastoral Constitution: "whatever is opposed to life itself, such as any type of murder, genocide, abortion, euthanasia, or willful self-destruction, whatever violates the integrity of the human person, such as mutilation, torments inflicted on body or mind, attempts to coerce the will itself; whatever insults human dignity, such as subhuman living conditions, arbitrary imprisonment, deportation, slavery, prostitution, the selling of women and children; as well as disgraceful working conditions, where people are treated as mere tools for profit, rather than as free and responsible persons"; and having called by name the many different sins that are so frequent and widespread in our time, the Constitution adds: "All these things and others of their kind are infamies indeed. They poison human society, but they do more harm to those who practice them than to those who suffer from the injury. Moreover, they are a supreme dishonor to the Creator" By calling by their proper name the sins that most dishonor man, and by showing that they are a moral evil that weighs negatively on any balance- sheet of human progress, the Council also describes all this as a stage in "a dramatic struggle between good and evil, between light and darkness," which characterizes "all of human life, whether individual or collective." The 1983 Assembly of the Synod of Bishops on reconciliation and penance specified even more clearly the personal and social significance of human sin.