The Index Librorum Prohibitorum was a list of publications that the Catholic Church prohibited due to their content, deemed contrary to faith and morals. Established in 1557 during the Papacy of Paul IV, it served as a tool for controlling authors and ideas that could threaten Church doctrine. The index included works by notable philosophers, scientists, and writers, such as Galileo Galilei and Voltaire, reflecting the Church's historical role in intellectual censorship. By the mid-20th century, societal changes and the increasing value placed on freedom of expression led to mounting criticism of the Index's relevance and effectiveness.

In 1966, under the leadership of Pope Paul VI, the Vatican announced the abolition of the Index Librorum Prohibitorum. This decision came as part of the broader context of the Second Vatican Council, which sought to modernize the Church's practices and doctrines. The Council had already introduced significant reforms, aimed at increasing engagement with contemporary society and promoting dialogue with other faiths and cultures. The abolition of the Index was perceived as a move towards fostering a more open relationship with literature and promoting personal conscience among believers.

The decision was celebrated by many modernists within and outside the Church, who viewed it as a step towards intellectual freedom. It acknowledged the changing landscape of society and the need for the Church to adapt. While the Church no longer officially prohibited individual works, the underlying principles of adherence to faith and moral values remained in guiding the choices of the faithful. Thus, while removing the Index established a more permissive stance on literature, it did not entirely eliminate the Church's influence over moral and ethical considerations concerning reading materials.