This an excerpt of an important forty page article in the Dictionary of Christian Biography ed. by William Smith et al. It gives you a sense of how Lightfoot critically assessed the work of ‘the father of church history’— Eusebius of Caesarea. Chiefly he faults him for lack of knowledge of Latin and important Latin Fathers such as Tertullian. Here is a bit of what he says (thanks to the site www.tertullian.org/rpearse/eusebius/lightfoot.html):
“It will have appeared from this account that Eusebius had a truly noble conception of the work which he was taking in hand. It was nothing less than the history of a society which stood in an intimate relation to the Divine Logos Himself, a society whose roots struck down into the remotest past and whose destinies soared into the eternal future. He felt moreover that he himself lived at the great crisis in its history. Now at length it had conquered, or at least seemed to have conquered, the powers of this world. No such moment in its development had ever occurred before ; and it was difficult to see how any such could occur again. This was the very time therefore to place on record the incidents of its past career. Moreover, he had great opportunities, such as were not likely to fall to another. In his own episcopal city, perhaps in his own official residence, was the largest Christian library which had hitherto been got together—the books collected by his friend Pamphilus. Not far off, at Jerusalem, was another valuable library, collected in the earlier part of the preceding century by the bishop Alexander, and especially rich in the correspondence of men of letters and rulers in the church, “from which library,” writes Eusebius, “we too have been able to collect together the materials for this undertaking which we have in hand” (H. E. vi. 20). Moreover, he himself had been trained in a highly efficient school of literary industry under Pamphilus, while his passion for learning has rarely been equalled, perhaps never surpassed.
It must be confessed however that the execution of his work falls far short of the conception. The faults indeed are patent and tend to obscure the merits, so that an unjust depreciation of the work has too commonly been the consequence. Yet, with all allowance made for these, it is a noble monument of literary labour. He himself, as we have seen, pleads for indulgence, as one who is setting foot upon new ground, “nullius ante trita solo.” As he had no predecessor, so also he had no successor. Rufinus, Socrates, Sozomen, Theodoret, all commenced their work where he had ended. None ventured to go over the same ground again, but left him sole possessor of the field which he held by right of discovery and of conquest. The most bitter of his theological adversaries were forced to confess their obligations to him, and to speak of his work with respect. It is only necessary to reflect for a moment what a blank would be left in our knowledge of this most important chapter in all human history, if the narrative of Eusebius were blotted out, and we shall appreciate the enormous debt of gratitude which we owe to him. The little light which glimmered over the earliest history of Christianity in medieval times came ultimately from Eusebius alone, coloured and distorted in its passage through various media.
The two points which require consideration are (1) the range and adequacy of his materials (2) the use made of these materials.
1. The range of materials is astonishing when we consider that Eusebius was a pioneer breaking new ground. Some hundred works, in several cases very lengthy works, are either directly cited or referred to as read. When we remember that in many instances he would read an entire treatise through for the sake of one or two historical notices, while in many others he must have done the same without finding any thing which would serve his purpose, we are able to form some conception of the enormous labour involved in the work. This then is his strongest point. Yet even here deficiencies may be noted. He very rarely quotes the works of heresiarchs themselves, being content to give their opinions through the medium of their opponents’ refutations. A still greater defect is his ignorance of Latin literature and of Latin Christendom generally. Thus he knows nothing of Tertullian’s works, except the Apologeticum, which he quotes (ii. 2, 25, iii. 20, 33, v. 5) from a bad Greek translation (e. g. ii. 25, where the translator, being ignorant of the Latin idiom cum maxime, makes shipwreck of the sense). Of Tertullian himself he gives no account, but calls him a “Roman.” Pliny’s letter he only knows through Tertullian (iii. 33), and is unacquainted with the name of the province which Pliny governed. Of Hippolytus again he has very little information to comniunicate, and cannot even tell the name of his see (vi. 20, 22). His account of Cyprian too is meagre in the extreme (vi. 43, vii. 3), though Cyprian was for some years the most conspicuous figure in western Christendom, and died (AD. 258) not very long before his own birth. He betrays the same ignorance also with regard to the bishops of Rome. His dates here, strangely enough, are widest of the mark in the latter half of the 3rd century, close upon his own time. Thus he assigns to Xystus II. (d. AD. 258) eleven years (vii. 27) instead of eleven months ; to Eutychianus (d. AD. 283) ten months (vii. 32) instead of nearly nine years; to Gaius, whom he calls his own contemporary, and who died long-after he had arrived at manhood (AD. 296), “about fifteen years” (vii. 32) instead of twelve. He seems to have had a corrupt list, and he did not possess the knowledge necessary to correct it. With the Latin language indeed he appears to have had no thorough acquaintance, though he sometimes ventured to translate Latin documents (iv. 8, 9; comp. viii. 17). But he must not be held responsible for the blunders in the versions of others, e.g. of Tertullian’s Apoloqeticum. Whether the translations of state documents in the later books are his own or not does not appear. But as Constantine was in the habit of employing persons to translate his state papers, speeches, &c., from Latin into Greek (V.C. iv. 32), we may suppose that Eusebius generally availed himself of such official or semiofficial versions. See on this subject Heinichen’s note on H.E. iv. 8.
This treatment may be regarded as too great a sacrifice to edification. It may discredit his conception of history; but it leaves no imputation on his honesty. Nor again can the special charges against his honour as a narrator be sustained. There is no ground whatever for the surmise that Eusebius forged or interpolated the passage from Josephus relating to our Lord quoted in H. E. i 11, though Heinichen (iii. p. 623 sq., Melet. ii.) is disposed to entertain the charge. Inasmuch as this passage is contained in all our extant MSS, and there is sufficient evidence that other interpolations (though not this) were introduced into the text of Josephus long before his time (see Orig. c. Cels. i. 47, Delarue’s note), no suspicion can justly . attach to Eusebius himself. Another interpolation in the Jewish historian, which he quotes elsewhere (ii. 23), was certainly known to Origen (l. c.). Doubtless also the omission of the owl in the account of Herod Agrippa’s death (H. E. ii. 10) was already in some texts of Josephus (Ant. xix. 8, 2). The manner in which Eusebius deals with his very numerous quotations elsewhere, where we can test his honesty, is a sufficient vindication against this unjust charge.1
Moreover, Eusebius is generally careful not only to collect the best evidence accessible, but also to distinguish between different kinds of evidence. “Almost every page witnesses to the zeal with which he collected testimonies from writers who lived at the time of the events which he describes. For the sixth and seventh books he evidently rejoices to be able to use for the foundation of his narrative the contemporary letters of Dionysius; ‘Dionysius, our great bishop of Alexandria,’ he writes, ‘will again help me by his own words in the composition of my seventh book of the history, since he relates in order the events of his own time in the letters which he has left’ (vii. praef.) . . . In accordance with this instinctive desire for original testimony, Eusebius scrupulously distinguishes facts which rest on documentary from those which rest on oral evidence. Some things he relates on the authority of a ‘general’ (iii. 11, 36) or ‘old report’ (iii. 19, 20) or from tradition (i. 7, . 9, vi. 2, &c.). In the lists of successions he is careful to notice where written records failed him. ‘I could not,’ he says, ‘ by any means find the chronology of the bishops of Jerusalem preserved in writing; thus much only I received from written sources, that there were fifteen bishops in succession up to the date of the siege under Hadrian, &c.’ (iv. 5).” [W.] “There is nothing like hearing the actual words” of the writer, he says again and again (i. 23, iii. 32, vii. 23; comp. iv. 23), when introducing a quotation.
The general sincerity and good faith of the historian seem therefore to be assured. But his intellectual qualifications for his task were in many respects defective. His credulity indeed has frequently been much exaggerated. “Undoubtedly he relates many incidents which may seemto us incredible, but, when he does so, he gives the evidence on which they are recommended to him. At one time it is the express testimony of some well-known writer, at another a general belief, at another an old tradition, at another his own observation (v. 7, vi. 9, vii. 17, 18)” [W.]. The most remarkable passage bearing on the question is one in which he recounts his own experience during the last persecution in Palestine (Mart. Pal. 9). “There can be no doubt about the occurrence which Eusebius here describes, and it does not appear that he can be reproached for adding the interpretation which his countrymen placed upon it. What he vouches for we can accept as truth ; what he records as a popular comment leaves his historical veracity and judgment unimpaired.” Gibbon (c. xvi) describes the character of Eusebius as “less tinctured with credulity, and more practised in the arts of courts, than that of almost any of his contemporaries.”
A far more serious drawback to his value as a historian is the loose and uncritical spirit in which he sometimes deals with his materials. This shews itself in diverse ways. (a) He is not always to be trusted in his discrimination of genuine and spurious documents. …