By juxtaposing the Church’s definition of Liturgy and the Mass with the myriad of post-conciliar liturgical changes, it becomes apparent there has been a deliberate intent to shift from the Catholic idea of the Mass as a propitiatory sacrifice to the Modernist idea of the "Eucharistic celebration" as a "communal, fraternal meal". To correct this, the Church must return to the conciliar document on the liturgy, Sacrosanctum Concilium, and "reform the liturgical reform" according to the intention of the Council Fathers, and in harmony with Tradition and the spirit of the liturgy. To this end, the many changes are explored, the Church’s liturgical laws are consulted, and Sacrosanctum Concilium is re-applied to the preconciliar liturgy.