1 A sense of the dignity of the human person has been impressing itself more and more deeply on the consciousness of contemporary man, and the demand is increasingly made that men should act on their own judgment, enjoying and making use of a responsible freedom, not driven by coercion but motivated by a sense of duty. The demand is likewise made that constitutional limits should be set to the powers of government, in order that there may be no encroachment on the rightful freedom of the person and of associations. This demand for freedom in human society chiefly regards the quest for the values proper to the human spirit. It regards, in the first place, the free exercise of religion in society. This Vatican Council takes careful note of these desires in the minds of men. It proposes to declare them to be greatly in accord with truth and justice. To this end, it searches into the sacred tradition and doctrine of the Church-the treasury out of which the Church continually brings forth new things that are in harmony with the things that are old. First, the council professes its belief that God Himself has made known to mankind the way in which men are to serve Him, and thus be saved in Christ and come to blessedness. We believe that this one true religion subsists in the Catholic and Apostolic Church, to which the Lord Jesus committed the duty of spreading it abroad among all men. Thus He spoke to the Apostles: "Go, therefore, and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all things whatsoever I have enjoined upon you" (Matt. 28: 19-20). On their part, all men are bound to seek the truth, especially in what concerns God and His Church, and to embrace the truth they come to know, and to hold fast to it. This Vatican Council likewise professes its belief that it is upon the human conscience that these obligations fall and exert their binding force. The truth cannot impose itself except by virtue of its own truth, as it makes its entrance into the mind at once quietly and with power. Religious freedom, in turn, which men demand as necessary to fulfill their duty to worship God, has to do with immunity from coercion in civil society. Therefore it leaves untouched traditional Catholic doctrine on the moral duty of men and societies toward the true religion and toward the one Church of Christ. Over and above all this, the council intends to develop the doctrine of recent popes on the inviolable rights of the human person and the constitutional order of society.
Source: Dignitatis Humanae (Vatican.va)