Pisa, Arezzo, and the other subject cities of Tuscany were treated by her with such selfish harshness that they proved her chiefest peril in the hour of need.[1] Competition in commerce increased the mutual hatred of the free burghs.

States like Venice, Florence, Pisa, Genoa, depending for their existence upon mercantile wealth, and governed by men of business, took every opportunity they could of ruining a rival in the market.

So mean and narrow was the spirit of Italian policy that no one accounted it unpatriotic or dishonorable for Florence to suck the very life out of Pisa, or for Venice to strangle a competitor so dangerous as Genoa.
[1] See the instructions furnished to Averardo dei Medici, quoted by Von Reumont in his _Life of Lorenzo_, vol.ii.p.

122, German edition.
Thus the jealousy of state against state, of party against party, and of family against family, held Italy in perpetual disunion; while diplomatic habits were contracted which rendered the adoption of any simple policy impossible.

When the time came for the Italians to cope with the great nations of Europe, the republics of Venice, Genoa, Milan, Florence ought to have been leagued together and supported by the weight of the Papal authority.