In his book, Les Principe des Theologie Catholique, Joseph Ratzinger states: ‟Let us content ourselves here with stating that the text [of the Vatican II Constitution, Gaudium et spes] plays the role of a counter-Syllabus to the measure that it represents an attempt to officially reconcile the Church with the world as it had become after 1789.” 1 What Ratzinger is saying is that Vatican II changed the errors condemned in the Syllabus of Errors by Pope Pius IX into truth, which is impossible. Can two plus two equal four a century ago and twenty-two today?
What this is saying is that what was false in 1863 and was condemned in the Syllabus of Errors could become true in 1962-5 at Vatican II.
On December 7, 1965, the Second Ecumenical Council of the Vatican would define as a matter of Faith for the Conciliar Church: “This Vatican Council declares that the human person has a right to religious freedom. This freedom means that all men are to be immune from coercion on the part of individuals or of social groups and of any human power, in such wise that no one is to be forced to act in a manner contrary to his own beliefs, whether privately or publicly, whether alone or in association with others, within due limits. The council further declares that the right to religious freedom has its foundation in the very dignity of the human person as this dignity is known through the revealed word of God and by reason itself. This right of the human person to religious freedom is to be recognized in the constitutional law whereby society is governed and thus it is to become a civil right.” Dignitatis Humanae, December 7, 1965, paragraph 2
Using the same principle Ratzinger caused the condemnation of the errors of Antonio Rosmini-Serbatti to be over turned, when he was a Cardinal. After he was elected Antipope, he beatified Antonio Rosmini-Serbatti.
The principle then is that truth can change, which is a Modernist, not a Catholic principle.