Pius XII Assisi Allocution (1956): critique of tendencies in the Liturgical Movement, including the separation of altar and tabernacle
This important allocution was included in the Acta Apostolicis Sedis, and so it is an act of the Papal Magisterium. As such it is refered to in the Decree of the Congregation of Rites which appeared the following year, Sanctissimam Eucharistiam, which is also on the LMS website. While praising the good results of the Liturgical Movement in general terms, the Allocution is composed of a series of criticisms of theological tendencies associated with the Movement, or some of its members. Here are some quotations.
Pius XII: Assisi Allocution 1956
Allocution of Pope Pius XII to the Assisi Liturgical Congress of 1956
Against the confusion of roles of celebrating priest and congregation (clerical or lay):
When the consecration of the bread and wine is validly performed, the entire action of Christ himself is accomplished. Even if all that follows cannot be carried out there is still nothing lacking to the offering of Christ. When the consecration is completed, the 'oblation of the Victim placed upon the altar' may be done and is done by the celebrating priest, by the Church, by the other priests and by each of the faithful, but this action is not the 'action of Christ Himself through a priest sustaining, and acting in, His person.' In truth the action of the consecrating priest is the very action of Christ, who acts by His minister.
Against the attack on the Real Presence.
For them the essential content of the species of bread and wine as they stand is 'Christ in heaven,' with whom the species have a so-called real, essential relation of containing and of presence. This speculative interpretation raises serious objections when it is put forward as completely sufficient, for the Christian sense of the faithful, the constant catechetical teaching of the Church, the expressions of the Council and particularly the words of our Lord, require that the Eucharist contain Christ Himself. The sacramental species are not Christ, even if they have a so-called essential relationship of containing and of presence with the substance of Christ in heaven. Our Lord said: 'This is my body! This is my blood!' He did not say: 'This is a sensible appearance which signifies the presence of my body and my blood.' Doubtless the sensible signs of a real relation of presence would be the sensible and efficacious signs of sacramental grace; but We are here concerned with the essential content of the 'eucharistic species,' not with their sacramental efficacy. One cannot, then, admit that the theory of which We are speaking does full justice to the words of Christ, that the presence of Christ in the Eucharist means no more than this and that this suffices to be able to say in very truth of the Eucharist: 'It is the Lord' (cf. John 21:7).
Against the view that the Tabernacle should be placed away from the Altar where Mass is celebrated.
It is not so much to the material presence of the tabernacle on the altar as to a tendency toward a lesser esteem for the presence and the action of Christ in the tabernacle that We would like to draw your attention. The sacrifice of the altar is considered sufficient, and the importance of Him who accomplished it is diminished. But the person of the Lord must occupy the centre of worship, for it is that which unifies the relations of the altar and the tabernacle and gives to them their meaning.
It is first of all by the sacrifice of the altar that our Lord makes Himself present in the Eucharist and He is in the tabernacle only as memoria sacrificii et passionis suae, a 'memorial of His sacrifice and passion.' To separate the tabernacle and the altar is to separate two things which should remain united by their origin and their nature.