The traditional ecclesiastical structure for the organisation of the Catholic Church, at the local level, is a geographical diocese under the authority of a bishop. A bishop appointed as a Diocesan Bishop, i.e. one entrusted with the responsibility of leadership of a diocese is conferred with ordinary jurisdiction and in canon law is known as an Ordinary. The important point here is that ecclesiatical authority does not reside in the ordination to the episcopate, per se, but in the the appointment of being an Ordinary. Assisant bishops in dioceses are an example of bishops who are not Ordinaries, ie they do not possess the capacity for ecclesiastical jurisdiction in their own right.
However, just as not all bishops are Ordinaries so too not all Ordinaries are bishops. The most common example of non-episcopal Ordinaries are abbots and some other heads of religious orders. Abbots exercise ecclesiastical authority within their own communities. On formal occasions, such for solemn professions, abbots will dress in mitres and possess a pastoral staff (even though they are not bishops) to signify they are acting in their capacity as an ecclesiastical Ordinary.
The diocese is an example of a geographical ecclesiastical administrative structure. There are, however, a few non-geographical dioceses with the military ordinariates being the most common example of these. The Catholic Military Ordinariate of Australia is consistuted by catholics in the Australian Defence Force across the whole of Australia and wherever else in the world ADF members are deployed. This non geographical diocese is administered by a bishop with the faculties of an Ordinary and thus this organisation is known by the term ordinariate. The personal ordinariates for former Anglicans is a more recent expression of a non-geographical diocese within the Latin Church.
Personal Ordinariates for former Anglicans
The Personal Ordinariates were established to provide a vehicle by which those of Anglican heritage could be received into full communion with the Catholic Church, as catholics, whilst maintaining certain disctinctive elements of their theological, spiritual and liturgical patrimony.
The key to understanding the essential purpose of the Ordinariate is to be found in the preface to Anglicanorum coetibus. In those opening paragraphs, there are no fewer than nine references to the Vatican II document Lumen Gentium, the Dogmatic Constitution on the Church.
Here the one Church of Jesus Christ is said to subsist in the Catholic Church: although many elements of sanctification and of truth are found outside of its visible structure, these elements, as gifts belonging to the Church of Christ, are forces impelling toward catholic unity.
There is an inner dynamic in the life and teaching of Anglicanism which continues to draw Anglicans to its source. The Personal Ordinariate is Pope Benedict XVI’s response to “this holy desire.”