Without stirring abroad, One can know the whole world; Without looking out of the window One can see the way of heaven. The further one goes The less one knows.
At 15 I set my heart on learning; At 30 I firmly took my stand; At 40 I had no delusions; At 50 I knew the Mandate of Heaven; At 60 my ear was attuned; At 70 I followed my heart's desire without overstepping the boundaries of right.
As to those other things which we hold on the authority, not of Scripture, but of tradition, and which are observed throughout the whole world, it may be understood that they are held as approved and instituted either by the apostles themselves, or by plenary Councils, whose authority in the Church is most useful, e.g. the annual commemoration, by special solemnities, of the Lord's passion, resurrection, and ascension, and of the descent of the Holy Spirit from heaven, and whatever else is in like manner observed by the whole Church wherever it has been established.
Christianity as a specific doctrine was slain with Jesus, suddenly and utterly. He was hardly cold in his grave, or high in his heaven (as you please), before the apostles dragged the tradition of him down to the level of the thing it has remained ever since.