Cicero

 From Cicero's Commonwealth we have:

Nature itself, however, required that, as a result of their having been freed from monarchy, the people should claim rather more rights for themselves; that took place not much later (about sixteen years) in the consulate of Postumus Cominius and Spurius Cassius.This development was perhaps not completely rational, but the nature of commonwealths often overcomes reason. You must bear in mind what I said at the outset: if there isn’t an equitable balance in the state of rights and duties and responsibilities, so that there’s enough power in the hands of the magistrates and enough authority in the judgment of the aristocrats and enough freedom in the people, then the condition of the commonwealth can’t be preserved unchanged. Now when the state was disturbed as a result of the problem of debt, the plebs seized first the Sacred Mount, and then the Aventine. Not even the discipline of Lycurgus was able to keep firm hold of the reins in dealing with Greeks: even at Sparta, in the reign of Theopompus, the five ephors (as they are called at Sparta; in Crete they are the ten cosmoi) were established as a check on the kings’ strength, just as the tribunes of the plebs were established against consular power.

Worth reading. There needs be a balance of power and debt can be the great destroyer of any Commonwealth.