In the first thousand years of Christianity, bishops of Rome used the title "vicar of Peter" (Peter being the leader of the Jesus' immediate students/followers, called apostles). The title "vicar of Christ" gradually came into use after the monastic and papal reforms of the 11th century.
The new official Catechism of the Catholic Church quotes John Cardinal Newman, writing at the time of the First Vatican Council: "Conscience is the aboriginal Vicar of Christ" (no. 1778). --CGE
On Sun, 16 Jan 2005, John Thornton wrote:
> >Interesting. By this logic, then, a call to lift the Cuba embargo--
> >insofar as it benefits the Catholic Church and helps the Church
> >expound Catholic faith in Cuba--would fall in the realm of infallibility.
> >Am I missing something here? (As I said, I don't know much about
> >Catholicism.)
> >
> >Miles
>
> The last "ex cathedra" pronouncement from the Vatican that I know of
> was in the sixties. It was an encyclical teaching against
> contraceptive use. There is some argument within the church about this
> because it is a stupid teaching and eventually they will find a way to
> finesse their way around it. Nothing the current pontiff said in his
> speech concerning Cuba would qualify as infallible. An interesting
> aspect about infallibility is that the "list" of qualifications for
> infallibility was not issued either "ex cathedra" or even as an
> Authentic Magesterium (this is disputed by some) so in essence the
> list is non-infallible and subject to revision. The comment was also
> posted that catholics would be uncomfortable with the characterization
> of the pope as "gods representative on earth". When issuing "ex
> cathedra" pronouncements via encyclical letter or some such other
> contrivance the pope is referred to as the "vicar of christ" but some
> popes used "vicar of god" which is basically the same as saying
> "substitute for christ". More than a mere representative they believe
> themselves an actual substitute!
>
> Vicar \Vic"ar\ (v[i^]k"[~e]r), n. [OE. vicar, viker, vicair, F.
> vicaire, fr. L. vicarius.]
> 1. One deputed or authorized to perform the functions of
> another; a substitute in office; a deputy. [R.]
> [1913 Webster]