 He was no longer satisfied with his chair as the means of propagating his ideas, and soon after his return from Bruges he began to express them in tracts and longer works.In a book concerned with the government of God and the Ten Commandments, he attacked the temporal rule of the clergy, the collection of annates, indulgences, and simony.He entered the politics of the day with his great work "De civili dominio" ("On Civil Dominion").