The dynamic of politics is that oligarchy and democracy tend towards tyranny and the destruction of stability and freedom, that is towards the factional violence and silence of civil war. Consider this chart. At a certain point the wealthy or the poor become arbitrary in rule, overturn all law and become tyrannical. Politics is lost. Any faction that charges things or causes great disturbances, this includes both popular uprising, coup de etat, power grabbing by faction.
Faction destroys common good and often leads to violence.
Aristotle observes revolution often comes from questions of honor and wealth, that is, seeking profit or honor and avoiding loss and dishonor. These are the motivating factors. Note - honor and wealth create discord and faction because they cannot be easily shared. Wealth cannot be had in common - it is appropriated as thine or mine ultimately. Like the body, it is private.