HAving throughout the whole Work us'd the Common and accustom'd Libertyof an Historian, we have both prais'd the Good, and condemn'd the Bad as they have fallen in our way, to the end that those whose Genius and Inclination prompts them to Virtue, may be the more encourag'd to Noble Actions, in hopes of having the Glory of their Names continu'd to all succeeding Generations; and on the other hand, that they that are bent to Wickedness may be curb'd and restrain'd from the Heat, at least, of their Impiety, by those marks of Dishonour and Disgrace fix'd upon them.
Since therefore we have brought down our History to the times wherein the Lacedaemonians fell by the sudden and unexpected Slaughter at Leuctra, and the like again not long after at Mantinea, whereby they lost the Sovereignty of Greece; We judge it part of our Province to keep close to the former Course and Method of Writing, (and therefore by the way in the first place to blame and reprehend the Lacedaemonians who justly deserve it: For who cannot but judge them worthy of Censure, and that justly, who having a well-settled Empire and Government descended to them from their Ancestors, and by their Valour supported and defended for the space of above Five hundred Years, should now in a Moment ruine it by their own Folly and Imprudence? For they that were before them, preserv'd the Grandeur and Glory of their Conquests, by their Lenity and Tenderness towards their Subjects, but these their Posterity by their Cruelty to their Confederates, and Pride and Ambition in making War upon the Grecians, most deservedly lost all by their Rashness and Inconsideratness. For those that hated them for the Injuries they had before suffer'd, greedily took the advantage now they were low, to revenge themselves on them as their Enemies. And they whose Forefathers were never before Conquer'd, were so much the more despis'd, by how much they deserv'd the greater Contempt, who by their Vices had stain'd the Virtue and Glory of their Ancestors.
The Thebans therefore (who for many Ages before were forc'd to stoop to them as their Superiors; having now (beyond all Mens expectations) conquer'd the Lacedaemonians) were made Chief Commanders of Greece: But the Lacedaemonians, after they had once lost their hold, could never after recover their ancient Glory and Dignity. But enough of this, we shall now return to the Course of our History.
The preceding Book, the Fourteenth in Order, ends with the Ruine of Rhegium by Dionysius, and the Taking of Rome by the Gauls, which happen'd the Year next before the Expedition of the Persians into Cyprus against Evagoras. We shall her begin this Book with that War, and end it with the Year next preceding the Reign of Philip the Son of Amyntas.