In the third decade (Bks. XXI.-XXX.), in addition to Fabius Pictor (xx. 7), Piso (xxv. 39), Valerius Antias (xxv. 39, xxvi. 49, xxix. 35, xxx. 19 and 29), Claudius Quadrigarius (xxv. 39 auctor est Claudius qui annales Acilianos [i.e., of C. Acilius Glabrio, 2nd century B.C., Cic. De Off, iii. 115, Aul. Gell. vii. 14, 9, Plut. Cat. 22, IVIacrob. Sat. i. 5] ex Graeco in Latinum sermonem vertit), Cincius Alimentus (xxi. 38), we have some new names. L. Cae lius Antipater, a contemporary of C. Gracchus, who wrote a his tory of the Second Punic War (Cic., De Div i. 24, De Or. ii. 12, De Legg. i. 2, Brut. 26, Ad. Att. xiii. 8, Gell. x. 24, Valer. Max. i. 7), is cited in xxi. 38, xxii. 31, xxiii. 6, xxvi. II, XXV11. 27, xxviii. xxix. 27. Silenus (cf. H. Dessau, Ober die Quellen unseres Wissens vom zweiten punischen Kriegs, Hermes 51 [1916] p. seq.), of Cale Acte in Sicily, who was in the camp of Hannibal for part of the campaign (Corn. Nep. xxiii. 13.3 : "The events of this war have been recounted by many writers, but of these, two were with him in his camp and lived with him as long as fortune permitted, Silenus and Sosilus of Lacedaemon"), and whose work was used by Caelius Antipater (Cic., De Div. i. 24: "This is also in the Greek history of Silenus whom Caelius follows: he was a most careful follower of the affairs of Hannibal"), is referred to in xxvi. 49. Lastly, Polybius is cited once (xxx. 45 Polybius, haudquaquam spernendus auctor).
In the fourth and fifth decades (Bks. XXXI.-XLV.) the author ities cited are Claudius Quadrigarius (xxxiii. 10, xxxv. 14), Va lerius Antias (xxxii. 6, xxxiii. Jo, xxxiv. 15, xxxv. 2, xxxvi. 19 and 38, xxxviii. 50, xxxix. 22, xl. 29, X11. 32, X111. II, X11V. 13, xlv. 40), and Polybius (xxxiii. Io, xxxiv. 5o, xxxvi. 19, xxxix. 52, xlv. 45) The principle on which he proceeds is to use Polybius for matters concerning Greece and the East, the Roman writers for those con cerning Italy and Western Europe. In this way is explained the comparatively small use made of Polybius in the third decade which is occupied mainly with Rome and Roman affairs, for which Roman authorities were naturally more abundant.
A few examples will illustrate his method of dealing with his authorities. Mere vague rumour is always to be neglected in favour of written evidence: vi. 1, the history of Rome down to the capture of the city by the Gauls (390 B.c.) is obscure, "first through its antiquity and then because in those letters, the one faithful guardian of the memory of things (laterae, una custodia fidelis memoriae rerum gestarurn), were few and rare, and because such as existed in the journals (commentarii) of the pontifices or in other public or private memorials perished when Rome was burnt." When his authorities agree, he usually ac cepts them without comment. When they differ, he is sometimes content to state the different accounts without deciding between them, e.g., xxv. 39. More often he indicates his preference and the grounds on which it is based. In general, preference is given to the older and, if available, contemporary authority : viii. 40 "Nor is there extant any writer contemporary with those times on whom one could take one's stand as a sufficiently sure auth ority," cf. xxii. 7. Sometimes the ground is merely general prob ability: xxvii. 7 "The storming of Carthage I have put in this year, with many authorities, although I am not unaware that some put the capture of the city in the following year, because it seemed to me less likely that Scipio would have spent a whole year in Spain doing nothing," cf. vi. 2 I . "In the case of things so ancient I should be content if what looks like the truth were taken for true." Where the number of the slain and captured, or the amount of booty, is variously given, he prefers the middle estimate : xxvi. 49 "If we must agree with some authority, the middle estimate is likest the truth." Sometimes he admits that he can discover no ground for a decision : vii. 40 "It is not easy to prefer one account to another or one authority to another" (aut rem rei aut auctorem auctori praeferre). Sometimes, if he sees reason, he does not hesitate to reject all his authorities: xxii. 31 "Almost all the annalists say that Fabius was dictator when he fought against Hannibal. Caelius (Antipater) also writes that he was the first dictator created by the people. But it has escaped Caelius and the rest that only the consul Gnaeus Servilius, who was then far away in the province of Gaul, had the power to appoint a dictator. As the State, already terror stricken by disaster, could not await the delay thus occasioned, recourse was had to the appointment by the people of a pro dictator. The general's subsequent exploits, his eminent fame, and the exaggeration by his descendants in the title attached to his portrait, easily brought it about that he should be styled dictator instead of pro-dictator." For mere invention he has no place (xxii. 7 nihil haustum ex nano velim, quo nimis inclinant ferme scribentium animi), and the exaggerations of Valerius Antias (xxxiii., io Si V alerio quis credat omnium rerum immodice numerum augenti) are stigmatized with the utmost candour (xxvi. 49 adeo nullus mentiendi modus est).