The General Secretariat for the Synod has published this Preparatory Document to indicate the guiding principles that will direct the path of the Synod on Synodality. The solemn opening of the Synod will take place in Rome on October 9-10, 2021, and in the particular Churches on October 17; and will conclude in the Vatican in 2023 with the assembly of bishops from around the world. The Preparatory Document is intended above all to be an instrument facilitating the first phase of listening and consultation of the People of God in the particular Churches, which will take place from October 2021 to April 2022.