Me, and as I am in Thee, that they also may be one in us, THAT THE
WORLD MAY KNOW that Thou hast sent Me" (John xvii. 21). Unity, then,
is undeniably the test and sign-manual attached by Christ to His
Bride, the Church; the presence or absence of which must (if there be
any truth in God) determine the genuineness or the falsity of every
claimant.

Now, this mark is nowhere found outside the One, Holy, Catholic and
Apostolic Church, whose centre is in Rome.

Other Churches not merely do not possess unity. They do not possess so
much as the requisite machinery to produce it, nor even the means of
preserving it, if produced.

With us, on the contrary, it flows as naturally and as directly from
the recognised Supremacy and Infallibility of the Vicar of Christ as
light flows from the sun. It is so manifest that it would seem only
the blind can fail to see it: so that one is sometimes puzzled to know
how to excuse educated Protestants from the damnable sin of _vincible_
ignorance. Thus, the faithful throughout the entire world are in
constant communication with their respective pastors; the pastors, in
their turn, are in direct communication with their respective Bishops,
and the Bishops, dispersed throughout the length and breadth of
Christendom, are in close and direct communication with the one
Supreme and Infallible Ruler, whom the Lord has placed over all His
possessions; who has been promised immunity from error; and whose
special duty and office is to "confirm his brethren" (Luke xxii. 32).
By this most simple, yet most practical and effective expedient, the
very least and humblest catechumen in China or Australia is as truly
in touch with the central authority at the Vatican, and as completely