54 The relationship between man's freedom and God's law is most deeply lived out in the "heart" of the person, in his moral conscience. As the Second Vatican Council observed: "In the depths of his conscience man detects a law which he does not impose on himself, but which holds him to obedience. Always summoning him to love good and avoid evil, the voice of conscience can when necessary speak to his heart more specifically: 'do this, shun that'. For man has in his heart a law written by God. To obey it is the very dignity of man; according to it he will be judged (cf. Rom 2:14-16)". The way in which one conceives the relationship between freedom and law is thus intimately bound up with one's understanding of the moral conscience. Here the cultural tendencies referred to above — in which freedom and law are set in opposition to each other and kept apart, and freedom is exalted almost to the point of idolatry — lead to a "creative" understanding of moral conscience, which diverges from the teaching of the Church's tradition and her Magisterium.
Source: Veritatis Splendor (Vatican.va)