The Complete Aristotle (eng.)

is
a cause of revolution. Men who are themselves dishonored and who
see others obtaining honors rise in rebellion; the honor or
dishonor when undeserved is unjust; and just when awarded according
to merit.
    Again, superiority is a cause of revolution when one or more
persons have a power which is too much for the state and the power
of the government; this is a condition of affairs out of which
there arises a monarchy, or a family oligarchy. And therefore, in
some places, as at Athens and Argos, they have recourse to
ostracism. But how much better to provide from the first that there
should be no such pre-eminent individuals instead of letting them
come into existence and then finding a remedy.
    Another cause of revolution is fear. Either men have committed
wrong, and are afraid of punishment, or they are expecting to
suffer wrong and are desirous of anticipating their enemy. Thus at
Rhodes the notables conspired against the people through fear of
the suits that were brought against them. Contempt is also a cause
of insurrection and revolution; for example, in oligarchies—when
those who have no share in the state are the majority, they revolt,
because they think that they are the stronger. Or, again, in
democracies, the rich despise the disorder and anarchy of the
state; at Thebes, for example, where, after the battle of
Oenophyta, the bad administration of the democracy led to its ruin.
At Megara the fall of the democracy was due to a defeat occasioned
by disorder and anarchy. And at Syracuse the democracy aroused
contempt before the tyranny of Gelo arose; at Rhodes, before the
insurrection.
    Political revolutions also spring from a disproportionate
increase in any part of the state. For as a body is made up of many
members, and every member ought to grow in proportion, that
symmetry may be preserved; but loses its nature if the foot be four
cubits long and the rest of the body two spans; and, should the
abnormal increase be one of quality as well as of quantity, may
even take the form of another animal: even so a state has many
parts, of which some one may often grow imperceptibly; for example,
the number of poor in democracies and in constitutional states. And
this disproportion may sometimes happen by an accident, as at
Tarentum, from a defeat in which many of the notables were slain in
a battle with the Iapygians just after the Persian War, the
constitutional government in consequence becoming a democracy; or
as was the case at Argos, where the Argives, after their army had
been cut to pieces on the seventh day of the month by Cleomenes the
Lacedaemonian, were compelled to admit to citizen some of their
Perioeci; and at Athens, when, after frequent defeats of their
infantry at the time of the Peloponnesian War, the notables were
reduced in number, because the soldiers had to be taken from the
roll of citizens. Revolutions arise from this cause as well, in
democracies as in other forms of government, but not to so great an
extent. When the rich grow numerous or properties increase, the
form of government changes into an oligarchy or a government of
families. Forms of government also change—sometimes even without
revolution, owing to election contests, as at Heraea (where,
instead of electing their magistrates, they took them by lot,
because the electors were in the habit of choosing their own
partisans); or owing to carelessness, when disloyal persons are
allowed to find their way into the highest offices, as at Oreum,
where, upon the accession of Heracleodorus to office, the oligarchy
was overthrown, and changed by him into a constitutional and
democratical government.
    Again, the revolution may be facilitated by the slightness of
the change; I mean that a great change may sometimes slip into the
constitution through neglect of a small matter; at Ambracia, for
instance, the qualification for office, small at first, was
eventually reduced to nothing. For the Ambraciots thought that a
small qualification was much the same as none at all.
    Another cause of revolution is difference of races which do not
at once acquire a common spirit; for a state is not the growth of a
day, any more than it grows out of a multitude brought together by
accident. Hence the reception of strangers in colonies, either at
the time of their foundation or afterwards, has generally produced
revolution; for example, the Achaeans who joined the Troezenians in
the foundation of Sybaris, becoming later the more numerous,
expelled them;