"If you wish to participate in the Mass actively, you must follow with your eye, heart, and mouth all that happens on the altar. Further, you must pray with the Priest the holy words said by him in the Name of Christ and what Christ says by him. You have to associate your heart with the holy feelings which are contained in these words and in this manner you ought to follow all that happens at the altar. When acting in this way you have prayed Holy Mass." - St. Pius X