His principal work, Mysterium Fidei, written in 1921, was a comprehensive study of the Mass. Dealing with the sacrifice once offered by Christ, he describes the Mass as the Sacrifice of the Church and the Eucharist as a Sacrament. His contention was that there is a unity between Christ's sacrifice begun at the Last Supper, consummated on the Cross and Resurrection and continued in the Mass. There was only one immolation, that at Calvary, to which the supper looked forward and the Mass looks back. He defended himself against his critics in The Mystery of Faith and Human Opinion (1930).
Published works
The Mystery of Faith: Regarding The Most August Sacrament And Sacrifice Of The Body And Blood Of Christ (1921) (Mysterium Fidei)