The author of Acts refers to the Gospel specifically as “the first treatise,” ton prōton logon, (Act 1:1) and both are addressed to Theophilus (Luk 1:3; Act 1:1). He speaks of himself in both books as “me” (kamoi, Luk 1:3) and I made (epoiēsamēn, Act 1:1). He refers to himself with others as “we” and “us” as in Act 16:10, the “we” sections of Acts. The unity of Acts is here assumed until the authorship of Acts is discussed in Volume III. The same style appears in Gospel and Acts, so that the presumption is strongly in support of the author’s statement. It is quite possible that the formal Introduction to the Gospel (Luk 1:1-4) was intended to apply to the Acts also which has only an introductory clause. Plummer argues that to suppose that the author of Acts imitated the Gospel purposely is to suppose a literary miracle. Even Cadbury, who is not convinced of the Lucan authorship, says: “In my study of Luke and Acts, their unity is a fundamental and illuminating axiom.” He adds: “They are not merely two independent writings from the same pen; they are a single continuous work. Acts is neither an appendix nor an afterthought. It is probably an integral part of the author’s original plan and purpose.”

The proof of this position belongs to the treatment of Acts, but a word is needed here. The use of “we” and “us” in Act 16:10 and from Act 20:6 to the end of chapter Acts 28 shows it beyond controversy if the same man wrote the “we” sections and the rest of the Acts. This proof Harnack has produced with painstaking detail in his Date of the Acts and the Synoptic Gospels and in his volume The Acts of the Apostles and in his Luke the Physician.

The argument for this position lies in the use of medical terms throughout the Gospel and the Acts. Hobart in his Medical Language of St. Luke proves that the author of both Gospel and Acts shows a fondness for medical terms best explained by the fact that he was a physician. Like most enthusiasts he overdid it and some of his proof does not stand the actual test of sifting. Harnack and Hawkins in his Horae Synopticae have picked out the most pertinent items which will stand. Cadbury in his Style and Literary Method of Luke denies that Luke uses Greek medical words more frequently in proportion than Josephus, Philo, Plutarch, or Lucian. It is to miss the point about Luke merely to count words. It is mainly the interest in medical things shown in Luke and Acts. The proof that Luke is the author of the books does not turn on this fact. It is merely confirmatory. Paul calls Luke “the beloved physician” (ho iatros ho agapētos, Col 4:14), “my beloved physician.” Together they worked in the Island of Malta (Act 28:8-10) where many were healed and Luke shared with Paul in the appreciation of the natives who “came and were healed (etherapeuonto) who also honoured us with many honours.” The implication there is that Paul wrought miracles of healing (iasato), while Luke practised his medical art also. Other notes of the physician’s interest will be indicated in the discussion of details like his omitting Mark’s apparent discredit of physicians (Mar 5:26) by a milder and more general statement of a chronic case (Luk 8:43).

His name is not a common one, and is probably a shortened form of Lukios and Lukanos. Some of the manuscripts of the Gospel actually have as the title Kata Lukanon. Dean Plumptre suggests that the Latin poet Lucanus was named after Luke who probably was the family physician when he was born. That is conjecture as well as the notion of Hayes that, since the brothers Gallio and Seneca were uncles of Lucanus they were influenced by Luke to be friendly toward Paul both in Corinth and in Rome. It is probable that Luke was a Greek, certainly a Gentile, possibly a freedman. So this man who wrote more than one-fourth of the New Testament was not a Jew. It is not certain whether his home was in Antioch or in Philippi. It is also uncertain whether he was already converted when Paul met him at Troas. The Codex Bezae has a “we” passage after Act 11:27 which, if genuine, would bring Luke in contact with Paul before Troas. Hayes thinks that he was a slave boy in the family of Theophilus at Antioch, several conjectures in one. We do not know that Theophilus lived at Antioch. It may have been Rome. But, whether one of Paul’s converts or not, he was a loyal friend to Paul. If he lived at Antioch, he could have studied medicine there and the great medical temple of Aesculapius was at Aegae, not far away. As a Greek physician, Luke was a university man and in touch with the science of his day. Greek medicine is the beginning of the science of medicine as it is known today. Tradition calls him a painter, but of that we know nothing. Certainly he was a humanist and a man of culture and broad sympathies and personal charm. He was the first genuine scientist who faced the problem of Christ and of Christianity. It must be said of him that he wrote his books with open mind and not as a credulous enthusiast.

There are two outstanding facts to mark off the date of this Gospel by Luke. It was later than the Gospel of Mark since Luke makes abundant use of it. It was before the Acts of the Apostles since he definitely refers to it in Act 1:1. Unfortunately the precise date of both termini is uncertain. There are still some scholars who hold that the author of the Acts shows knowledge of the Antiquities of Josephus and so is after a.d. 85, a mistaken position, in my opinion, but a point to be discussed when Acts is reached. Still others more plausibly hold that the Acts was written after the destruction of Jerusalem and that the Gospel of Luke has a definite allusion to that event (Luk 21:20.), which is interpreted as a prophecy post eventum instead of a prediction by Christ a generation beforehand. Many who accept this view hold to authorship of both Acts and Gospel by Luke. I have long held the view, now so ably defended by Harnack, that the Acts of the Apostles closes as it does for the simple and obvious reason that Paul was still a prisoner in Rome. Whether Luke meant the Acts to be used in the trial in Rome, which may or may not have come to pass, is not the point. Some argue that Luke contemplated a third book which would cover the events of the trial and Paul’s later career. There is no proof of that view. The outstanding fact is that the book closes with Paul already a prisoner for two years in Rome. If the Acts was written about a.d. 63, as I believe to be the case, then obviously the Gospel comes earlier. How much before we do not know. It so happens that Paul was a prisoner a little over two years in Caesarea. That period gave Luke abundant opportunity for the kind of research of which he speaks in Luk 1:1-4. In Palestine he could have access to persons familiar with the earthly life and teachings of Jesus and to whatever documents were already produced concerning such matters. Luke may have produced the Gospel towards the close of the stay of Paul in Caesarea or during the early part of the first Roman imprisonment, somewhere between a.d. 59 and 62. The other testimony concerns the date of Mark’s Gospel which has already been discussed in volume I. There is no real difficulty in the way of the early date of Mark’s Gospel. All the facts that are known admit, even argue for a date by a.d. 60. If Mark wrote his Gospel in Rome, as is possible, it would certainly be before a.d. 64, the date of the burning of Rome by Nero. There are scholars, however, who argue for a much earlier date for his gospel, even as early as a.d. 50. The various aspects of the Synoptic problem are ably discussed by Hawkins in his Horae Synopticae, by Sanday and others in Oxford Studies in the Synoptic Problem, by Streeter in his The Four Gospels, by Hayes in his The Synoptic Gospels and the Book of Acts, by Harnack in his Date of the Acts and the Synoptic Gospels, by Stanton in his The Gospels as Historical Documents, and by many others. My own views are given at length in my Studies in Mark’s Gospel and in Luke the Historian in the Light of Research.

In his Preface or Prologue (Luk 1:1-4) the author tells us that he had two kinds of sources, oral and written, and that they were many, how many we have no way of telling. It is now generally accepted that we know two of his written sources, Mark’s Gospel and Q or the Logia of Jesus (written by Matthew, Papias says). Mark is still preserved and it is not difficult for any one by the use of a harmony of the Gospels to note how Luke made use of Mark, incorporating what he chose, adapting it in various ways, not using what did not suit his purposes. The other source we only know in the non-Markan portions of Matthew and Luke, that is the material common to both, but not in Mark. This also can be noted by any one in a harmony. Only it is probable that this source was more extensive than just the portions used by both Matthew and Luke. It is probable that both Matthew and Luke each used portions of the Logia not used by the other. But there is a large portion of Luke’s Gospel which is different from Mark and Matthew. Some scholars call this source L. There is little doubt that Luke had another document for the material peculiar to him, but it is also probable that he had several others. He spoke of “many.” This applies especially to chapters 9 to 21. But Luke expressly says that he had received help from “eye-witnesses and ministers of the word,” in oral form this means. It is, then, probable that Luke made numerous notes of such data and used them along with the written sources at his command. This remark applies particularly to chapters 1 and 2 which have a very distinct Semitic (Aramaic) colouring due to the sources used. It is possible, of course, that Mary the mother of Jesus may have written a statement concerning these important matters or that Luke may have had converse with her or with one of her circle. Ramsay, in his volume, Was Christ Born at Bethlehem? shows the likelihood of Luke’s contact with Mary or her circle during these two years at Caesarea. Luke handles the data acquired with care and skill as he claims in his Prologue and as the result shows. The outcome is what Renan called the most beautiful book in the world.

Literary charm is here beyond dispute. It is a book that only a man with genuine culture and literary genius could write. It has all the simple grace of Mark and Matthew plus an indefinable quality not in these wonderful books. There is a delicate finish of detail and proportion of parts that give the balance and poise that come only from full knowledge of the subject, the chief element in a good style according to Dr. James Stalker. This scientific physician, this man of the schools, this converted Gentile, this devoted friend of Paul, comes to the study of the life of Christ with a trained intellect, with an historian’s method of research, with a physician’s care in diagnosis and discrimination, with a charm of style all his own, with reverence for and loyalty to Jesus Christ as Lord and Saviour. One could not afford to give up either of the Four Gospels. They each supplement the other in a wonderful way. John’s Gospel is the greatest book in all the world, reaching the highest heights of all. But if we had only Luke’s Gospel, we should have an adequate portrait of Jesus Christ as Son of God and Son of Man. If Mark’s is the Gospel for the Romans and Matthew’s for the Jews, the Gospel of Luke is for the Gentile world. He shows the sympathy of Jesus for the poor and the outcast. Luke understands women and children and so is the universal Gospel of mankind in all phases and conditions. It is often called the Gospel of womanhood, of infancy, of prayer, of praise. We have in Luke the first Christian hymns. With Luke we catch some glimpses of the child Jesus for which we are grateful. Luke was a friend and follower of Paul, and verbal parallels with Paul’s Epistles do occur, but there is no Pauline propaganda in the Gospel as Moffatt clearly shows (Intr. to Lit. of the N.T., p. 281). The Prologue is in literary Koiné and deserves comparison with those in any Greek and Latin writers. His style is versatile and is often coloured by his source. He was a great reader of the Septuagint as is shown by occasional Hebraisms evidently due to reading that translation Greek. He has graciousness and a sense of humour as McLachlan and Ragg show. Every really great man has a saving sense of humour as Jesus himself had. Ramsay dares to call Luke, as shown by the Gospel and Acts, the greatest of all historians not even excepting Thucydides. Ramsay has done much to restore Luke to his rightful place in the estimation of modern scholars. Some German critics used to cite Luk 2:1-7 as a passage containing more historical blunders than any similar passage in any historian. The story of how papyri and inscriptions have fully justified Luke in every statement here made is carefully worked out by Ramsay in his various books, especially in The Bearing of Recent Discovery on the Trustworthiness of the New Testament. The main feature of this proof appears also in my Luke the Historian in the Light of Research. So many items, where Luke once stood alone, have been confirmed by recent discoveries that the burden of proof now rests on those who challenge Luke in those cases where he still stands alone.