2. Luke's sources. — in the complete absence of any definite statements as to the sources used by Luke, with tlie exception of the preface to the Gospel, internal evidence can alone be used, and the results of its study are necessarily only tentative.
In the preface to the Gospel Luke tells us that he was acquainted with many previous attempts to give a SiriyrjffLV tQv veTr\Tipo<popr)fx4vuv 4v Tjfjuv TrpayiJidTwv — a difficult phrase, which, however, much more probably means 'the things accom- plished among us' than the 'things most surely believed among us' — in accordance with the tradition of the original eye-witnesses, and that he also had decided to write an account of them because he was irapriKoXovdrjKdTL dvudev TracTLV. From this passage it has sometimes been concluded that Luke disapproved of the previous efforts, and re- garded himself as altogether superior to his pre- decessors. This, however, is not the natural meaning of the Greek; Luke saj's : 'Inasmuch as many ... it seemed good to me also' {Kdp.oi), and the force of the 'also' is to class him with and not above his predecessors. A more serious problem is provided by the exact exegesis of TrS.cn, in P. Does it refer to the iroXXoi of 1^, or to the TTpaynaTuiv of the Same verse, or to the avTo-n-raL of 1^? No decision is possible; the probability is rather in favour of a reference to ttoWoL, as carry- ing on and explaining the e-n-eibTj-n-ep ttoWoL of the opening words, but the other alternatives are possible. In any case, the main object of Luke was to provide Theophilus with the proof (iVa iTTiyvilis . . , Trjv d<r(pd.\eLav) of the "KSyoi in which he had received oral instruction (Karrixv^V^)- Luke is therefore -^Titing history with the object of giving the historical basis of the statements (pre- sumably theological) which were current in the oral instruction given to converts. VOL. I. — 46
(a) The icritten sources vsed by Luke. — In the Gospel at least two written sources can be detected. (1) Mark, either exactly in the form now extant, or in one only slightly differing from it, was certainly used by Luke. This is one of the most secure results of the criticism of the Synoptic Gospels. (2) Besides Mark, Luke used a docu- ment commonly called Q {Quelle), which was also used by Matthew, and, according to some scholars (not, the present writer thinks, correctly), by Mark. The exact contents of Q cannot be defined. Nor can we say with certainty whether Q represents one or many documents. These points are at present among the most warmly debated and most intently studied problems in the Sj-noptic question. If, however, Q be used to cover all the material common to Matthew and Luke, and it be assiuned that Q is only one docimient, it must have been Greek, not Aramaic, as the agreement between Matthew and Luke is often too close to admit the possibility that the two narratives re- present two translations of a single Aramaic docu- ment. In the same way the Mark used bj- Matthew and Luke must have been Greek ; it is, however, possible, though no sufficient proof has been given even by WelLhausen, that behind the Greek IMark and the Greek Q there were originally Aramaic texts. (3) It is doubtful whether Luke used other WTitten sources in his Gospel. It is possible that the Persian section 9^^-18^ may have had a WTitten source, and the same may be said of the ' Jerusalem narrative' of the Passion and Resurrection ; but it is also possible that their pecuUarly Lucan passages rest on oral tradition. (4) In the Acts much depends on the view taken of the critical questions, but in any case the 'we-sections' must be referred to a written source, even though their source may have been a diary of the editor of the whole book. Whether the 'Antiochene' source was a WTitten document is doubtful, and the same may be said of source B in the Jerusalem-Casarsean tradition. It is, however, as probable as any point which is supported merely by hterarj^ evidence can be that source A (containing Ac 3—4, probably 8^*, and possibly also ch. 5) depends from a written Greek source (see art. Acts for the fuller treatment of the question of the sources of Acts).
(b) The use of the LXX. — It remains a question which criticism has as yet found no means of solving whether Luke used, besides the foregoing sources, an Aramaic document for his narrative of the Nativity in the Gospel, or gave his version of a tradition which he had heard, casting it into a form based on the LXX. It is in any case certain that the LXX, and not the Hebrew, was the form of the OT which he habitually used, and his diction seems to have been greatly influenced by it.
(c) The tise of other writings. — No other books seem to have been certainly used by Luke, with the possible (or, in the present writer's opinion, probable) exception of Josephus. The facts re- lating to Josephus in connexion with Theudas seem to point very strongly to a knowledge of the Antiquities (see art. Acts).
(f/) The use of the Epistles. — There is no reason to suppose that Luke was acquainted with any of the Pauline Epistles. There is nothing in the Acts which resembles a quotation, and in relating facts alluded to in the Epistles there is more often difference than agreement, even though it be true that the difference is not always very serious.