When the Church, then, was thrown upon her own resources, first local disturbances gave exercise to Bishops, and next ecumenical disturbances gave exercise to Popes; and whether communion with the Pope was necessary for Catholicity would not and could not be debated till a suspension of that communion had actually occurred. It is not a greater difficulty that St. Ignatius does not write to the Asian Greeks about Popes, than that St. Paul does not write to the Corinthians about Bishops. And it is a less difficulty that the Papal supremacy was not formally acknowledged in the second century, than that there was no formal acknowledgment on the part of the Church of the doctrine of the Holy Trinity till the fourth. No doctrine is defined till it is violated.
And, in like manner, it was natural for Christians to direct their course in matters of doctrine by the guidance of mere floating, and, as it were, endemic tradition, while it was fresh and strong; but in proportion as it languished, or was broken in particular places, did it become necessary to fall back upon its special homes, first the Apostolic Sees, and then the See of St. Peter.
An Essay on the Development of Christian Doctrine, Chapter IV, Section III, paragraph 4