"As for the Roman constitution, it had three elements, each of them possessing sovereign powers: and their respective share of power in the whole state had been regulated with such a scrupulous regard to equality and equilibrium, that no one could say for certain, not even a native, whether the constitution as a whole were an aristocracy or democracy or despotism. And no wonder: for if we confine our observation to the power of the Consuls we should be inclined to regard it as despotic; if on that of the Senate, as aristocratic; and if finally one looks at the power possessed by the people it would seem a clear case of democracy."
Could someone please explain the meaning of this quote from The Histories of Polybius Book VI and its significance?