That Xerxes’s army was extremely numerous I can readily believe, both from the great extent of his empire and from the foolish practice of the Eastern nations of encumbering their camp with a superfluous multitude; but will any rational man cite Herodotus’s wonderful narrations as an authority? There is something very rational, I own, in Lysias’s argument upon this subject. Had not Xerxes’ army been incredibly numerous, says he, he had never built a bridge over the Hellespont: it had been much easier to have transported his men over so short a passage, with the numerous shipping of which he was master. Polybius says that the Romans, between the first and second Punic Wars, being threatened with an invasion from the Gauls, mustered all their own forces and those of their allies, and found them amount to seven hundred thousand men able to bear arms. A great number surely, and which, when joined to the slaves, is probably not less, if not rather more than that extent of country affords at present.​[72] The enumeration too seems to have been made with some exactness, and Polybius gives us the detail of the particulars; but might not the number be imagined in order to encourage the people? Diodorus Siculus makes the same enumeration amount to near a million. These variations are suspicious. He plainly, too, supposes that Italy in his time was not so populous, another very suspicious circumstance; for who can believe that the inhabitants of that country diminished from the time of the first Punic War to that of the Triumvirates? Julius Cæsar, according to Appian, encountered four millions of Gauls, killed one million, and took another million prisoners.​[73] Supposing the number of the enemy’s army and of the killed could be exactly assigned, which never is possible, how could it be known how often the same man returned into the armies, or how distinguish the new from the old levied soldiers? No attention ought ever to be given to such loose, exaggerated calculations; especially where the author tells us not the mediums upon which the calculations were founded. Paterculus makes the number killed by Cæsar amount only to 400,000: a much more probable account, and more easily reconciled to the history of these wars given by that conqueror himself in his _Commentaries_.