Legislative, executive, and judicial power. In a state, power is the name for the force established in the hands of one or of many.

In each state, three sorts of capacities or powers are distinguished: [1] legislative power , the executive power over things that depend on the law of nations—in other words, the executive power of the state—and the executive power over things that depend on civil law. [2]

By the first, the prince or the state makes laws for a temporary or permanent period, and corrects or abrogates those already made. By the second, it makes peace or war, sends or receives ambassadors, establishes security, prevents invasions. By the third, it punishes crimes or judges disputes between individuals; that is why we call this latter the judicial power .

Liberty must extend to all individuals, as equally enjoying the same nature. If it is limited to certain persons, it would be better for it not to exist at all, since then it furnishes a dreadful comparison that aggravates the unhappiness of those deprived of it.

There is less risk of losing liberty when the legislative power is in the hands of many persons who differ by status and interest. But where it is at the discretion of those who are alike in these two things, the government is not far from falling into the despotism of monarchy. Liberty is never more assured than when the legislative power is entrusted to different persons so happily distinguished from each other that, in working for their own interest, they advance the interest of the whole people—or, to use different terms, when there is not a single sector of the people that does not have a shared interest with at least a portion of the legislators.

If there is only one body of legislators, this is scarcely better than tyranny. If there are only two, one of them risks being swallowed up over time by the disputes that arise between them; they will need a third to tip the scales. There would be the same drawback with four, and a larger number would cause too much trouble. I have never been able to read a passage in Polybius on this score, and another in Cicero, without tasting a secret pleasure in applying them to the government of England, with which they are much more closely connected than with that of Rome. [3] These two great authors give preference to government composed of three bodies—the monarchical, the aristocratic, and the popular. They doubtless had the Roman republic in mind, where the consuls represented the king, the senators the nobles, and the tribunes the people. These three powers that one sees in Rome were not as distinct or as natural as they seem in Great Britain’s form of government. The governments of most ancient republics suffered this abuse: that the people were at the same time both judge and accuser. But since the legislative body is composed of two parts in the government of which we are speaking, one binds the other by its natural faculty of vetoing, and both are bound by the executive power , which is itself bound by the legislative power . See the details on this in the work on l’esprit des lois , bk. II. ch. vi . [4] It is enough for me to remark in general that political liberty is lost in a state if the same man, or the same body of leaders or of nobles or of the people, exercise the three powers —that of making the laws, that of executing public resolutions, and that of judging crimes or private differences.

1. Jaucourt’s distinction here is between pouvoir, which we translate as “capacity” because of its broader connotations, and puissance, which usually connotes a specifically human authority—whether familial, religious, or political. See the article Power.

2. This definition, and the next paragraph, come from Montesquieu, The Spirit of the Laws , 11.6, on the English constitution.

3. On the mixed constitution to which Jaucourt refers, see for example Polybius, Histories , 6.10–14; Cicero, De Republica , bk. 1.

4. The discussion appears in Montesquieu, Spirit of the Laws, 11.6.