SYLLABUS OF PIUS X. A series of propositions condemned by the Congregation of the Holy Office and ratified by the Pope as decreed in the encyclical Lamentabili (July 3, 1907). It denounced the tenets of Modernism and repudiated their errors. The basis of these false doctrines was the pseudo-scientific theory of evolution on human knowledge and belief. By a subsequent motu proprio the Pope further confirmed the syllabus by publishing the Oath Against Modernism (September 1, 1910).