The faint traditionary traces which inform us that St. Matthew and St. Mark were supposed to have written Gospels fail us with St. Luke. The apostolic and the immediately post-apostolic Fathers never mention Luke as having written a history of our Lord at all. There was indeed a Gospel in use among the Marcionites which resembled that of St. Luke, as the Gospel of the Ebionites resembled that of St. Matthew. In both the one and the other there was no mention of our Lord's miraculous birth; and later writers accused Marcion of having mutilated St. Luke. But apparently their only reason for thinking so was that the two Gospels were like each other; and for all that can be historically proved, the Gospel of the Marcionites may have been the older of the two. What is wanting externally, however, is supposed to be more than made up by the language of St. Luke himself. The Gospel was evidently composed in its present form by the same person who wrote the Acts of the Apostles. In the latter part of the Acts of the Apostles the writer speaks in the first person as the companion of St. Paul; and the date of this Gospel seems to be thus conclusively fixed at an early period in the apostolic age. There is at least a high probability that this reasoning is sound; yet it has seemed strange that a convert so eminent as 'the most excellent' Theophilus, to whom St. Luke addressed himself, should be found impossible to identify. 'Most excellent' was a title given only to persons of high rank; and it is singular that St. Paul himself should never have mentioned so considerable a name. And again, there is something peculiar in the language of the introduction to the Gospel itself. Though St. Luke professes to be writing on the authority of eye-witnesses, he does not say he had spoken with eye-witnesses; so far from it, that the word translated in the English version 'delivered' is literally 'handed down;' it is the verb which corresponds to the technical expression for 'tradition;' and the words translated 'having had perfect understanding of all things from the first,' might be rendered more properly, 'having traced or followed up all things from the beginning.' And again, as it is humanly speaking certain that in St. Luke's Gospel there are passages, however they are to be explained, which were embodied in it from some other source, so, though extremely probable, it is not absolutely certain that those passages in the Acts in which the writer speaks in the first person are by the same hand as the body of the narrative. If St. Luke had anywhere directly introduced himself--if he had said plainly that he, the writer who was addressing Theophilus, had personally joined St. Paul, and in that part of his story was relating what he had seen and heard, there would be no room for uncertainty. But, so far as we know, there is no other instance in literature of a change of person introduced abruptly without explanation.