Two continuous successions of able and virtuous princes will achieve great results.
As well-constituted republics have, in the nature of things, a succession of virtuous rulers, their acquisitions and extension will consequently be very great.
After Rome had expelled her kings she was no longer exposed to the dangers which we have spoken of above, as resulting from a succession of feeble or wicked kings; for the sovereign authority was vested in the Consuls, who obtained that authority not by inheritance, or fraud, or violent ambition, but by the free suffrages of the people, and were generally most excellent men. Rome, having the benefit of the virtue and good fortune of these men from time to time, was thus enabled to attain her utmost grandeur in no greater length of time than she had existed under the rule of kings. For if, as has been seen, two successive good and valorous princes are sufficient to conquer the world, as was the case with Philip of Macedon and Alexander the Great, a republic should be able to do still more, having the power to elect not only two successions, but an infinite number of most competent and virtuous rulers one after the other; and this system of electing a succession of virtuous men should ever be the established practice of every republic.
Oh for one single able and virtuous ruler!