Which philosopher said this?

Aristotle on government..."When a change of constitution takes place, Kingship pes into Tyranny, because Tyranny is the bad form of monarchy, so that a bad king becomes a tyrant. Aristocracy pes into Oligarchy owing to badness in the rulers, who do not distribute what the State has to offer according to desert, but give all or most of its benefits to themselves, and always ign the offices to the same persons, because they set supreme value upon riches; thus power is in the hands of a few bad men, instead of being in the hands of the best men. Timocracy pes into Democracy, there being an affinity between them, inasmuch as the ideal of Timocracy also is government by the m of the citizens, and within the property qualifications all are equal. Democracy is the least bad of the perversions, for it is only a very small deviation from the constitutional form of government. These are the commonest ways in which revolutions occur in states, since they involve the smallest change, and come about most easily."