The Permanent Instruction of the Alta Vendita is a secret document created by the Alta Vendita, the highest lodge of the Italian Carbonari, a Masonic organization operating in the 19th century. This document outlines a covert plan to infiltrate and corrupt the Catholic Church from within rather than attacking it directly. Unlike previous anti-Catholic movements that sought to destroy the Church through force, the Alta Vendita's strategy focused on gradual infiltration, ensuring that over time, the Church would adopt secular and modernist ideas. The document was leaked and published by the Vatican in the 19th century and was later endorsed by Popes Pius IX and Leo XIII, who saw it as a real threat to the Catholic faith.