A Course of Studies of the Acts of the Magisterium on Modern Errors:
Errors of Modernism in philosophical foundation, concepts of Faith, dogmatic theology, apologetic methods and critical principles
The following encyclicals clearly show the difference between Church Teaching before and after the Second Vatican Council
Pope Pius IX "Syllabus of Modern Errors"
Dec 8 1864
Pope Pius X "Lamentabili"
July 3 1907
Pope Pius X "Pascendi"
On modernist errors on philosophical principles
Sept 8 1907
Pope Pius X "Anti-modernist Oath"
Sept 1 1910