In some cases all that is wanted to solve the difficulty is proper understanding of Luke's words. That, for example, is the case with Acts 11:28, where the statement, that in the days of Claudius there was famine over all the world, has been misinterpreted to imply that harvests failed and a famine ensued in every part of the whole world at exactly the same time, which would be an obvious exaggeration, and therefore not entirely trustworthy: it would be quite in the rhetorical style of Tacitus or Juvenal, not in the simple and true manner of Luke.
But, as all the commentators have pointed out, Suetonius, Dion Cassius, Tacitus and Eusebius mention scarcity occurring at different times in widely scattered parts of the Roman world during that reign; and an inscription has been interpreted (though not with certainty) as referring to a famine in Asia Minor some years before AD.56.  At no period in Roman history are so many allusions to widespread famine found as under Claudius. Luke refers to what must then have been an accepted belief, that at some time or other during the reign of Claudius every part of the Roman world suffered from famine.
A much more difficult case occurs in Acts 5:36-37, where Gamaliel in addressing the Sanhedrin says: "Before these days rose up Theudas, giving himself out to be somebody, to whom a number of men, about 400, joined themselves, who was slain, and all, as many as obeyed him, were dispersed and came to naught. And after this man rose up Judas the Galilean in the days of the enrollment' and caused people to revolt under his leadership: he also perished; and all, as many as obeyed him, were scattered abroad."
Now Josephus describes "a certain magician, named Theudas, who, while Fadus was Procurator of Judea, persuaded most of the people ton pleiston ochlon to take up their property and follow him to the river Jordan; for he told them he was a prophet, and he said that he would divide the river by his command and afford them easy passage through it; and he deceived many by telling them this. Fadus, however, did not permit them to profit by their folly, but sent a squadron of cavalry against them, which falling unexpectedly upon them, slew many of them and captured many alive. And they took Theudas himself alive and cut off his head and brought it to Jerusalem "(Ant Jud., 20., 5, 1).
In the following paragraph Josephus describes what happened under the government of Tiberius Alexander, the successor of Fadus; and, among other things, he tells that "the sons of Judas the Galilean were slain, viz., that Judas who caused the people to revolt from the Romans when Quirinius was making the valuation of Judea".
It is pointed out that in two successive paragraphs Josephus speaks first of Theudas and then of Judas, dating the latter under Quirinius; and that in two successive verses Luke speaks first of Theudas and then of Judas, dating the latter at the great enrollment (i.e., under Quirinius). From this the inference is drawn that Luke, reading hurriedly and carelessly the passage of Josephus, falsely inferred that Theudas, who is mentioned first, was the elder; and they point to the analogy, between the two accounts of Judas,  as evidence that Luke borrowed from Josephus.
Finally, since Josephus's Theudas rose and fell several years after Gamaliel is supposed to have delivered his speech, they infer that Luke had no authority for the words which he puts into Gamaliel's mouth, but freely invented the whole according to a common practice among ancient historians. Luke, as they say, constructed a suitable speech for Gamaliel out of his own scrappy and inaccurate reading, and thus made Gamaliel describe an event that had not yet occurred, supposing it to have taken place before AD.6.
Without doubt, if this theory is correct, we must throw up our whole case as hopeless. The blunder attributed to Luke is so ingeniously many-sided as to destroy his credit in various directions. It shows that he invented his speeches without authority; that he was incapable of reading two short paragraphs of Greek without misunderstanding them; that, even when he had a good authority before him, he could not report his information without introducing a portentous blunder; that he was so ignorant of Judean history as to think that an event which Josephus dates under Fadus could be, in the first place, older than Gamaliel's speech (delivered soon after AD.29 or 30), and, in the second place, older than the great enrollment. The most wretched old chronicler, in the worst and most ignorant Byzantine time, has not succeeded in doing anything so bad as that. To find a parallel instance of ignorance and stupidity, where knowledge is professed and must be expected, one must come down to modern times and look in the papers of rejected candidates in a "pass" examination, who have vainly tried, with the minimum of care and work, to delude the examiner into the belief that they know enough to be permitted to scrape through the test.
But is not this too gross a blunder? Is it credible that a person who was so shockingly ignorant and inaccurate should aspire to be a historian? The aspirations of men are usually Founded on the conscious possession of some qualifications for success. Luke evidently aimed -- and probably was the first to aim -- at connecting the story of the development of Christianity with the course of general Imperial history. Surely he would not have aimed at doing so, unless he possessed a certain moderate knowledge of that history. In his preface he declares that his motive for writing his work was that he was in possession of such exceptionally excellent information, gained from first-rate authorities. But only the grossest incapacity and ignorance combined could have enabled him to succeed in attaining so colossal a blunder.
The theory seems to me incredible, irrational, and psychologically impossible. It is irreconcilable with the known facts and the character of Luke's History; and I am confident that if it had been stated about any writer who was not a Christian, it would have been universally treated with the contempt that it merits. It is the sort of fancy that brands its originator and its believer as either lacking the critical faculty or blinded by prejudice.
Moreover, the theory is founded on an accidental peculiarity of order in the text of Josephus, and presupposes that Luke was indebted entirely to one passage of Josephus for his knowledge of Theudas and Judas. He could hardly have read any additional authority without acquiring some more correct idea as to the time when Theudas lived.
It is not here the place to discuss the question whether Luke had read Josephus. As Dr. Sanday  says, the assumption that he used the Jewish Antiquities "rests on little more than the fact that both writers relate or allude to the same events, though the differences between them are really more marked than the resemblances". He adds that "Schuerer  sums up the controversy by saying that either Luke had taken no notice of Josephus at all, which he thinks the simpler and more probable supposition, or at once forgot everything that he had read". The latter opinion is that of a scholar who believes Luke to have written after Josephus. We hold Luke to have written before him.
In truth there is between Luke and Josephus the minimum of resemblance and the maximum of discrepancy possible between two authorities writing about the same period, and both (as we believe) enjoying access to excellent authorities.
Moreover, it is clear, on the recognized principles of critical study, that Luke used some other authority and was not indebted to Josephus alone; for he mentions the exact number of persons who followed Theudas, viz., 400, whereas Josephus would lead one to believe that Theudas had a very much larger following.  Thus Luke had other means of learning the date of Theudas. It may be answered that Luke invented the number, and designedly or through incapacity varied from the account that Josephus gives. To that no reply need be given: they who say so will be ready to declare that Luke, who could read Josephus and suppose the procurator Fadus to be older than the great enrollment, was equally capable of reading any number of additional authorities without profiting by them!
We cannot, it is true, tell who was the Theudas to whom Gamaliel refers. The period is very obscure; Josephus is practically our only authority. He does not allude, or profess to allude, to every little disturbance on the banks of the Jordan. There is no real difficulty in believing that more than one impostor may have borne or taken the name Theudas; that one Theudas, amid the troubles that followed the death of Herod the Great (a period about which we have no information except that there were great troubles, calling for the presence of a Roman army from the Province Syria), or at some earlier time, pretended to be somebody, and found 400 followers; and that another Theudas, about AD.44-46, called himself a prophet, and led after him a great part of the Jewish people.
The result is, at present, disappointing. We have to leave the difficulty unsolved. We must hope for the discovery of further evidence. Meantime, no one who finds Luke to be a trustworthy historian in the rest of his History will see any difficulty in this passage.
But there is good cause to look forward confidently to the progress of discovery. The advance in knowledge, due to the increased activity in searching, has been immense during recent years. The whole essay, which has been here set before the public, is founded on one discovery; and after it was print it has been confirmed by a new find. 
We may suitably conclude the essay with another discovery, slight in itself, but significant of the general trend of advancing knowledge. 
The reference in Acts 10:1 to an Italic Cohort (of which Cornelius was a centurion) has caused some difficulty and discussion in recent years. Some excellent scholars have entertained the suspicion that this detail is an anachronism, caused by the intrusion of circumstances that were true at a later time into this early period. It is established by an inscription that an Italic Cohort was stationed in Syria at a considerably later time; and the theory is that Luke, knowing that such a Cohort was there at the time when he wrote, either incorrectly added this detail to the story which he learned about Cornelius, or in some other way manipulated or invented the story. What reason he had for so treating the story, and how precisely he treated it, the theory does not state. It simply casts discredit in a vague way on the story, accusing it of containing a false detail. 
Among non-theologians, Professor Mommsen pronounces no judgment, but avoids making any positive suggestion about the Cohort, in his illuminative paper in the Sitzungsberichte of the Berlin Academy, 1895, p.503.  Marquardt, in the work from which all study must always begin in these subjects, Romische Staatsverwaltung, 2., p.467, note 5, accepts the words of Acts as an ordinary authority, quoting them along with other references to an Italic Cohort. A recent discovery confirms the position taken by Marquardt, and will probably be held by most scholars as a sufficient proof that, in our present state of knowledge, the suspicion that has been entertained about the reference is contrary to the balance of evidence.
Dr. Bormann  publishes an inscription found recently at Carnuntum, one of the great military stations in Pannonia, on the south bank of the Danube, a little below Vienna. It is the epitaph of a young soldier, Proculus, a subordinate officer (optio) in the second Italic Cohort, who died at Carnuntum while engaged on detached service from the Syrian army (as an officer in a corps of archers from Syria, temporarily sent on special service and encamped at Carnuntum).  Proculus was born at Philadelphia (doubtless the city of that name beyond Jordan, the old Rabbath-Ammon), and his father bore the Syrian name Rabilus.
As to the date of this epitaph, Bormann and Domaszewski, two of the highest authorities, have come independently to the same conclusion. The epitaph was found with a group of others, stamped by criteria derived both from nomenclature, and from inscriptional and alphabetical character, as belonging to the period of the early emperors. This group belongs to all older cemetery, which was in use before AD.73, when a new camp near Carnuntum was built for the soldiers stationed there. Further, the service on which these Syrian soldiers had come to Carnuntum can be dated with the highest probability.
In AD.69, Syrian detachments to the number of 13,000 men swelled the army which Mucianus, governor of Syria, led westwards to support Vespasian in his struggle against Vitellius. But before Mucianus arrived on the scene, the armies of Pannonia and Moesia had declared for Vespasian, marched into Italy, and finished the contest. Their departure had left the northern frontier undefended against the barbarians, Dacians, Germans, etc., beyond the Danube. As Tacitus mentions, the Dacians showed signs of invading Moesia, and Mucianus dispatched the Sixth Legion  to guard against them on the Lower Danube. Tacitus does not say anything about the Upper Danube; but there also the danger was so obvious, that an experienced governor like Mucianus could hardly fail to send a guard thither also; for the words of Tacitus (Hist., 3., 46) show that he was fully alive to the danger all along the northern frontier. In this way we may conclude that part of the detachments came to Carnuntum; and there Proculus died, perhaps in AD.70. The Syrian armies were evidently soon sent back to the East, where the Sixth Legion is shortly afterwards mentioned as engaged in operations in the northern parts of Syria in 73.
There was therefore an Italic Cohort stationed in Syria in AD.69. It was recruited from Syria,  and therefore, according to the principle laid down by Mommsen, it belonged to the eastern Roman armies. It is therefore in every way probable that an Italic Cohort was stationed in the Province Syria, as Dr. Bormann has observed, about AD.40, when Cornelius is mentioned as "a centurion of the Cohort called Italic," resident in Caesarea (the Roman governmental center of Palestine).
This discovery, it is true, does not prove conclusively that the Italic Cohort, which had been stationed in Syria before AD.69, was there as early as about AD.40. It is not beyond the range of possibility that the Cohort might have been sent to Syria between 40 and 69. Movements of troops from province to province were not rare, and the Italic Cohort might have been moved in that interval. But, in general, the movements were caused by military requirements which can be ascertained. As Marquardt says of Syria, "the same Legions remained for centuries in the province," and they were divided between many different stations, not massed in single centers: for example, detachments of the Third Legion called Gallica, can be traced in Sidon, Beirut, Aera in the district Auranitis, and Phaena in Trachonitis. The whole burden of proof, therefore, rests with those who maintain that a Cohort which was in Syria before 69 was not there in 40. There is a strong probability that Luke is right when he alludes to that Cohort as part of the Syrian garrison about AD.40.
A series of arguments have been advanced to buttress this assumption that Luke when he spoke of an Italic Cohort in Syria about 40 was guilty of an anachronism.
It is pointed out, in the first place, that between AD.41 and 44, during which period Judea was formed into a dependent kingdom ruled by Herod Agrippa, a Roman Cohort would not be stationed in Caesarea. If this were certain, it would merely confirm the view taken by many scholars that the incident of Cornelius occurred earlier than 41. But as a matter of fact we know far too little of the relations between the rule of Agrippa and the provincial administration to be sure that a centurion would not be resident in Caesarea during his short reign. There is nothing more obscure than the precise terms on which the numerous dependent kingdoms in Asia Minor and Syria were administered. It is practically certain that these subject kingdoms were tributary from the first, even when they had never before been subject to Rome; and even Herod the Great's action was controlled by Rome in many important respects, and his subjects took an oath to be faithful to the Romans. But the Judean kingdom of Agrippa, as it existed in AD.41-44, had long been actually part of a Roman province; and there is great probability that it might retain certain relations with the provincial government, and that officers of the provincial soldiery might be kept resident in the capital, Caesarea, to maintain these relations. There is much that might be said on this point; but it is not necessary for our main purpose. Moreover, the whole subject is so obscure that a scholar who aims simply at understanding the subject will at present refrain from any dogmatic statement about it, and will certainly be very slow to condemn an ancient author for inaccuracy, because he does not confirm the modern scholar's hasty conjecture. All that need be said is that at present we find the argument so devoid of force that it hardly even affords any presumption in favor of a date for the incident of Cornelius earlier than AD.41.
In the next place it has been argued that even between AD.6 and 41, when Judea was part of the Province Syria, and when Roman auxiliary troops were stationed both at Caesarea and at Jerusalem, an Italic Cohort cannot have been stationed at Caesarea. This assertion is based on a series of conjectures as to the Roman forces stationed in Judea during these years. It is fortunately unnecessary for me to discuss these conjectures: I need only point out
(1) that they are in direct contradiction to the principles previously laid down by Mommsen, the supreme authority on the subject; 
(2) that Mommsen has now considered them and judged them to be "erroneous in every respect". 
But, further, even supposing that these conjectures were strong enough to support the conclusion that the Italic Cohort was not stationed in Caesarea, we know far too little to justify the inference that a centurion of that Cohort could not be on duty there, detached from his Cohort on special service. The entire subject of detachment-service is most obscure; and. we are very far from being able to say with certainty that the presence of an auxiliary centurion  in Caesarea is impossible, unless the Cohort in which he was an officer was stationed there.
Since the question of the Roman troops in Palestine is so full of difficulties, that it is hardly possible to make any assertion in the matter, what judgment should be pronounced on the light-heartedness which suspects Luke of inaccuracy, because he does not conform to the conjectures which some distinguished German professor sets forth? It is a matter of interest to observe how slow some very learned New Testament scholars are to appreciate the principle, which is regarded as fundamental by the historical and antiquarian students, that no conjecture which is not founded on clear evidence has any right even to be propounded, if it contradicts the direct statement of an ancient authority. Much less ought the ancient authority to be discredited because he disagrees with a loose and disputed modern conjecture.
The episode of Cornelius in Acts is characterized by that vagueness and want of direct, incisive statement of details, which Luke shows in handling the early history of the Church in Palestine. He was not at home in the province of Syria, and the Jewish people in particular he neither understood nor liked. If the narrative of Cornelius showed the same mastery of facts and surroundings as is apparent in Philippi or Ephesus or Cyprus or Athens, we should find it far more instructive than it is as to the way in which an officer of the Roman army of occupation lived. Was he resident in a private house? How was he in such close relations with the Jews throughout Palestine? Many questions suggest themselves, pressing for an answer, which I cannot give. But the tendency of discovery distinctly is, in this as in other cases, to confirm the trustworthiness of the general situation.
 St. Paul the Traveller, p. 48 f.  en tais hemerais tes apographes kai apestese laon opi so autou in Luke, and ton laon hapo apostesantos Kuriniou tes Ioudais timeteuontos in Josephus.  Bampton Lectures, 1893, p. 278.  Lucas und Josephus in Zeitschr. f. krit. Theologie, 1876, p. 574 ff. Josephus's great work on the Jewish Antiquities was written about AD. 93-94.  peithei ton pleiston ochlon . . . hepestha are his words.  See Preface.  The following paragraphs are shortened and modified (but without altering the opinions stated) from an article in the Expositor, September, 1896.  Steht . . . unter dem Verdacht, Verhaltnisse einer spateren Zeit in eine fruhere zuruck verlegt zu haben.  Mit Sicherheit vermoegen wir weder diese cohors Augusta (Acts 27:1) noch die speira Italike . . . zu identificieren.  Archaol. Epigr. Mittheil. aus Oesterreich, 1895, p. 218.  Ex vexil. sagit. exer. Syriaci, where Bormann's completion of the abbreviations seems beyond question ex vexillariis sagittariis exercitus Syriaci.  This Legion, called. Ferrata, was enrolled by Augustus and stationed in Syria. It formed part of Mucianus's army in AD. 69; and it remained in Judea at least as late as the third century.  Proculus was in his seventh year of service when he died, and had probably enlisted in AD. 64 (when he was nineteen years old).  See Mommsen in Hermes, 19., p. 217.  In jeder Hinsicht verfehlt, Mommsen in Berlin. Akad. Sitz. 1895, p. 501.  Auxiliary centurions, being of lower rank than legionary, were not employed as frumentarii (like Julius in Acts 27..); but there were other ways of detached service.
 en tais hemerais tes apographes kai apestese laon opi so autou in Luke, and ton laon hapo apostesantos Kuriniou tes Ioudais timeteuontos in Josephus.
 Bampton Lectures, 1893, p. 278.
 Lucas und Josephus in Zeitschr. f. krit. Theologie, 1876, p. 574 ff. Josephus's great work on the Jewish Antiquities was written about AD. 93-94.
 peithei ton pleiston ochlon . . . hepestha are his words.
 See Preface.
 The following paragraphs are shortened and modified (but without altering the opinions stated) from an article in the Expositor, September, 1896.
 Steht . . . unter dem Verdacht, Verhaltnisse einer spateren Zeit in eine fruhere zuruck verlegt zu haben.
 Mit Sicherheit vermoegen wir weder diese cohors Augusta (Acts 27:1) noch die speira Italike . . . zu identificieren.
 Archaol. Epigr. Mittheil. aus Oesterreich, 1895, p. 218.
 Ex vexil. sagit. exer. Syriaci, where Bormann's completion of the abbreviations seems beyond question ex vexillariis sagittariis exercitus Syriaci.
 This Legion, called. Ferrata, was enrolled by Augustus and stationed in Syria. It formed part of Mucianus's army in AD. 69; and it remained in Judea at least as late as the third century.
 Proculus was in his seventh year of service when he died, and had probably enlisted in AD. 64 (when he was nineteen years old).
 See Mommsen in Hermes, 19., p. 217.
 In jeder Hinsicht verfehlt, Mommsen in Berlin. Akad. Sitz. 1895, p. 501.
 Auxiliary centurions, being of lower rank than legionary, were not employed as frumentarii (like Julius in Acts 27..); but there were other ways of detached service.