Ten years ago this month, on June 29th, 1943, to be exact, His Holiness Pope Pius XII issued the encyclical Mystici Corporis. The publication of this doctrinal instruction was providential, as any comparison between manuals of ecclesiology written prior to its appearance and the texts which have been printed during the last ten years will very easily attest. It is only fitting that Catholic theologians throughout the world should take cognizance of this anniversary, and try, on this occasion, to appreciate some of the great benefits God has granted to His kingdom on earth through this doctrinal letter of Our Lord's vicar on earth.
The central pronouncement in the encyclical Mystici Corporis is to be found in the declaration that the expression "Mystical Body of Jesus Christ" is actually a definition of the Church. In the words of the Holy Father, "If we would define and describe this true Church of Jesus Christ - which is the One, Holy, Catholic, Apostolic, Roman Church - we shall find no expression more noble, more sublime, or more divine, than the phrase which calls it 'the Mystical Body of Jesus Christ.'" Fenton