No one would claim that the rules by which scientific historians of to-day are judged should be applied to those that wrote when history was young, when the boundaries between the possible and the impossible were less clearly defined, or when, in fact, such boundaries hardly existed in men's minds. In this connection, even while we vaunt, we smile. After all, how much of our modern and so-called scientific history must strike the reasoning reader as mere theorizing or as special pleading based upon the slenderest evidence! Among the ancients the work of the historians whom we consider trustworthy--such writers, for instance, as Cæsar, Thucydides, Xenophon, Polybius, and Tacitus--may be said to fall generally within Rawlinson's canons 1 and 2 of historical criticism--that is, (1) cases where the historian has personal knowledge concerning the facts whereof he writes, or (2) where the facts are such that he may reasonably be supposed to have obtained them from contemporary witnesses. Canon 2 might be elaborated and refined very considerably and perhaps to advantage. It naturally includes as sources of knowledge--first, personal interviews with contemporary witnesses; and, second, accesses to the writings of historians whose opportunities brought them within canon 1. In this latter case the evidence would be less convincing, owing to the lack of opportunity to cross-question, though even here apparent lack of bias or the existence of biased testimony on both sides, from which a judicious man might have a fair chance to extract the truth, would go far to cure the defect.
The point, however, to which I tend is, that the portions of Livy's history from which we must judge of his trustworthiness treat, for the most part, of periods concerning which even his evidence was of the scantiest and poorest description. He doubtless had family records, funeral panegyrics, and inscription--all of which were possibly almost as reliable as those of our own day. Songs sung at festivals and handed down by tradition may or may not be held more truthful. These he had as well; but the government records, the ancient fasti, had been destroyed at the time of the burning of the city by the Gauls, and there is no hint of any Roman historian that lived prior to the date of the second Punic war. Thus we may safely infer that Livy wrote of the first five hundred years without the aid of any contemporary evidence, either approximately complete or ostensibly reliable. With the beginning of the second Punic war began also the writing of history. Quintus Fabius Pictor had left a work, which Polybius condemned on the score of its evident partiality. Lucius Cincius Alimentus, whose claim to knowledge if not to impartiality rests largely on the fact that he was captured and held prisoner by Hannibal, also left memoirs; but Hannibal was not famous for treating prisoners mildly, and the Romans, most cruel themselves in this respect, were always deeply scandalized by a much less degree of harshness on the part of their enemies. Above all, there was Polybius himself, who perhaps approaches nearer to the critical historian than any writer of antiquity, and it is Polybius upon whom Livy mainly relies through his third, fourth, and fifth decades. The works of Fabius and Cincius are lost. So also are those of the Lacedaemonian Sosilus and the Sicilian Silanus, who campaigned with Hannibal and wrote the Carthaginian side of the story; nor is there any evidence that either Polybius or Livy had access to their writings. Polybius, then, may be said to be the only reliable source from which Livy could draw for any of his extant books, and before condemning unqualifiedly in the cases where he deserts him and harks back to Roman authorities we must remember that Livy was a strong nationalist, one of a people who, despite their conquests, were essentially narrow, prejudiced, egotistical; and, thus remembering, we must marvel that he so fully recognises the merit of his unprejudiced guide and wanders as little as he does. All told, it is quite certain that he has dealt more fairly by Hannibal than have Alison and other English historians by Napoleon. His unreliability consists rather in his conclusions than in his facts, and it is unquestioned that through all the pages of the third decade he has so told the story of the man most hated by Rome--the deadliest enemy she had ever encountered--that the reader can not fail to feel the greatness of Hannibal dominating every chapter.