Book III, Chapter X
the abuse of government and its tendency to degenerate
As the particular will acts constantly in opposition to the general will, the government continually exerts itself against the Sovereignty. The greater this exertion becomes, the more the constitution changes; and, as there is in this case no other corporate will to create an equilibrium by resisting the will of the prince, sooner or later the prince must inevitably suppress the Sovereign and break the social treaty. This is the unavoidable and inherent defect which, from the very birth of the body politic, tends ceaselessly to destroy it, as age and death end by destroying the human body.
There are two general courses by which government degenerates: i.e. when it undergoes contraction, or when the State is dissolved.
Government undergoes contraction when it passes from the many to the few, that is, from democracy to aristocracy, and from aristocracy to royalty. To do so is its natural propensity.  If it took the backward course from the few to the many, it could be said that it was relaxed; by this inverse sequence is impossible.
Indeed, governments never change their form except when their energy is exhausted and leaves them too weak to keep what they have. If a government at once extended its sphere and relaxed its stringency, its force would become absolutely nil, and it would persist still less. It is therefore necessary to wind up the spring and tighten the hold as it gives way: or else the State it sustains will come to grief.
The dissolution of the State may come about in either of two ways.
First, when the prince ceases to administer the State in accordance with the laws, and usurps the Sovereign power. A remarkable change then occurs: not the government, but the State, undergoes contraction; I mean that the great State is dissolved, and another is formed within it, composed solely of the members of the government, which becomes for the rest of the people merely master and tyrant. So that the moment the government usurps the Sovereignty, the social compact is broken and all private citizens recover by right their natural liberty, and are forced, but not bound, to obey.
The same thing happens when the members of the government severally usurp the power they should exercise only as a body; this is as great an infraction of the laws, and results in even greater disorders. There are then, so to speak, as many princes as there are magistrates, and the State, no less divided than the government, either perishes or changes its form.
When the State is dissolved, the abuse of government, whatever it is, bears the common name of anarchy. To distinguish, democracy degenerates into ochlocracy and aristocracy into oligarchy and I would add that royalty degenerates into tyranny; but this last word is ambiguous and needs explanation.
In vulgar usage, a tyrant is a king who governs violently and without regard for justice and law. In the exact sense, a tyrant is an individual who arrogates to himself the royal authority without having a right to it. This is how the Greeks understood the word "tyrant": they applied it indifferently to good and bad princes whose authority was not legitimate.  Tyrant and usurper are thus perfectly synonymous terms.
In order that I may give different things different names, I call him who usurps the royal authority tyrant, and him who usurps the sovereign power a despot. The tyrant is he who thrusts himself in contrary to the laws to govern in accordance with the laws; the despot is he who sets himself above the laws themselves. Thus the tyrant cannot be a despot, but the despot is always a tyrant.
 The slow formation and the progress of the Republic of Venice in its lagoons are a notable instance of this sequence; and it is most astonishing that, after more than twelve hundred years' existence, the Venetians seem to be still at the second stage, which they reached with the Serrar di Consiglio in 1198. As for the ancient Dukes who are brought up against them, it is proved, whatever the Squittinio della libertà veneta may say of them, that they were in no sense Sovereigns.
A case certain to be cited against my view is that of the Roman Republic, which, it will be said, followed exactly the opposite course, and passed from monarchy to aristocracy and from aristocracy to democracy. I by no means take this view of it.
What Romulus first set up was a mixed government, which soon deteriorated into despotism. From special causes, the State died an untimely death, as new-born children sometimes perish without reaching manhood. The expulsion of the Tarquins was the real period of the birth of the Republic. But at first it took on no constant form, because, by not abolishing the patriciate, it left half its work undone. For, by this means, hereditary aristocracy, the worst of all legitimate forms of administration, remained in conflict with democracy, and the form of the government, as Macchiavelli has proved, was only fixed on the establishment of the tribunate: only then was there a true government and a veritable democracy. In fact, the people was then not only Sovereign, but also magistrate and judge; the senate was only a subordinate tribunal, to temper and concentrate the government, and the consuls themselves, though they were patricians, first magistrates, and absolute generals in war, were in Rome itself no more than presidents of the people.
From that point, the government followed its natural tendency, and inclined strongly to aristocracy. The patriciate, we may say, abolished itself, and the aristocracy was found no longer in the body of patricians as at Venice and Genoa, but in the body of the senate, which was composed of patricians and plebeians, and even in the body of tribunes when they began to usurp an active function: for names do not affect facts, and, when the people has rulers who govern for it, whatever name they bear, the government is an aristocracy.
The abuse of aristocracy led to the civil wars and the triumvirate. Sulla, Julius Cæsar and Augustus became in fact real monarchs; and finally, under the despotism of Tiberius, the State was dissolved. Roman history then confirms, instead of invalidating, the principle I have laid down.
 Omnes enim et habentur et dicuntur tyranni, qui potestate utuntur perpetua in ea civitate quæ libertate usa est (Cornelius Nepos, Life of Miltiades). [For all those are called and considered tyrants, who hold perpetual power in a State that has known liberty.] It is true that Aristotle (Nicomachean Ethics, Book viii, chapter x) distinguishes the tyrant from the king by the fact that the former governs in his own interest, and the latter only for the good of his subjects; but not only did all Greek authors in general use the word tyrant in a different sense, as appears most clearly in Xenophon's Hiero, but also it would follow from Aristotle's distinction that, from the very beginning of the world, there has not yet been a single king.