In "The Spirit of the Liturgy", Cardinal Joseph Ratzinger (later Pope Benedict XVI) attributed to the influence of Saint Peter's Basilica the fact that other churches in Rome are built with the apse to the west and also attributed to topographical circumstances that arrangement for Saint Peter's. However, the arrangement whereby the apse with the altar is at the west end of the church and the entrance on the east is found also in Roman churches contemporary with Saint Peter's (such as the original Basilica of Saint Paul Outside the Walls) that were under no such constraints of terrain, and the same arrangement remained the usual one until the 6th century. In this early layout, the people were situated in the side aisles of the church, not in the central nave. While the priest faced both the altar and east throughout the Mass, the people would face the altar (from the sides) until the high point of the Mass, where they would then turn to face east along with the priest.