At what time, by what hands, under what circumstances, have the Gospels been compiled?
This is the primary question upon which depends the opinion to be formed of their credibility.
Each of the four Gospels bears at its head the name of a personage, known either in the apostolic history, or in the Gospel history itself.

These four personages are not strictly given us as the authors.

The formulae "according to Matthew," "according to Mark," "according to Luke," "according to John," do not imply that, in the most ancient opinion, these recitals were written from beginning to end by Matthew, Mark, Luke, and John,[1] they merely signify that these were the traditions proceeding from each of these apostles, and claiming their authority.

It is clear that, if these titles are exact, the Gospels, without ceasing to be in part legendary, are of great value, since they enable us to go back to the half century which followed the death of Jesus, and in two instances, even to the eye-witnesses of his actions.
[Footnote 1: In the same manner we say, "The Gospel according to the Hebrews," "The Gospel according to the Egyptians."] Firstly, as to Luke, doubt is scarcely possible.

The Gospel of Luke is a regular composition, founded on anterior documents.[1] It is the work of a man who selects, prunes, and combines.