Answer: By creating an index of banned works
Explanation: Also known as the Index of Forbidden Books, the purpose of which was to Counter-Reformation and prevent the canonical rules of the Catholic Church. As the Reformation itself meant some changes and different interpretations of the basic principles of the Catholic Church, this Index was to prevent any change and violation of the Catholic Faith. Thus, all books containing material that would "corrupt" or "misinterpret" the Catholic faith were found in this Index.