CHAPTER XXV.—That he who attacks a City divided against itself, must not think to get possession of it through its Divisions.
Violent dissensions breaking out in Rome between the commons and the nobles, it appeared to the Veientines and Etruscans that now was their time to deal a fatal blow to the Roman supremacy. Accordingly, they assembled an army and invaded the territories of Rome. The senate sent Caius Manlius and Marcus Fabius to meet them, whose forces encamping close by the Veientines, the latter ceased not to reproach and vilify the Roman name with every sort of taunt and abuse, and so incensed the Romans by their unmeasured insolence that, from being divided they became reconciled, and giving the enemy battle, broke and defeated them. Here, again, we see, what has already been noted, how prone men are to adopt wrong courses, and how often they miss their object when they think to secure it. The Veientines imagined that they could conquer the Romans by attacking them while they were at feud among themselves; but this very attack reunited the Romans and brought ruin on their assailants. For the causes of division in a commonwealth are, for the most part, ease and tranquillity, while the causes of union are fear and war. Wherefore, had the Veientines been wise, the more divided they saw Rome to be, the more should they have sought to avoid war with her, and endeavoured to gain an advantage over her by peaceful arts. And the best way to effect this in a divided city lies in gaining the confidence of both factions, and in mediating between them as arbiter so long as they do not come to blows; but when they resort to open violence, then to render some tardy aid to the weaker side, so as to plunge them deeper in hostilities, wherein both may exhaust their forces without being led by your putting forth an excess of strength to suspect you of a desire to ruin them and remain their master. Where this is well managed, it will almost always happen that you succeed in effecting the object you propose to yourself.
The city of Pistoja, as I have said already in connection with another matter, was won over to the Florentine republic by no other artifice than this. For the town being split by factions, the Florentines, by now favouring one side and now the other, without incurring the suspicions of either, brought both to such extremities that, wearied out with their harassed life, they threw themselves at last of their own accord into the arms of Florence. The city of Siena, again, has never made any change in her government which has had the support of the Florentines, save when that support has been slight and insignificant; for whenever the interference of Florence has been marked and decided, it has had the effect of uniting all parties in support of things as they stood.
One other instance I shall add to those already given. Oftener than once Filippo Visconti, duke of Milan, relying on their divisions, set wars on foot against the Florentines, and always without success; so that, in lamenting over these failures, he was wont to complain that the mad humours of the Florentines had cost him two millions of gold, without his having anything to show for it. The Veientines and Etruscans, therefore, as I have said already, were misled by false hopes, and in the end were routed by the Romans in a single pitched battle; and any who should look hereafter to prevail on like grounds and by similar means against a divided people, will always find themselves deceived.