In his encyclical Nostis et nobiscum of December 8, 1849, Pius IX denounces a false understanding of these words.
“As regards this teaching and these theories [about distancing the peoples of Italy from obedience to the Pope and the Holy See], it is now generally known that the special goal of their proponents is to introduce to the people the pernicious fictions of Socialism and Communism by misapplying the terms liberty and equality.”
Plinio Corrêa de Oliveira, Nobility and Analogous Traditional Elites in the Allocutions of Pius XII: A Theme Illuminating American Social History (York, Penn.: The American Society for the Defense of Tradition, Family, and Property, 1993), Appendix III, p. 383.
