Montesquieu's Spirit of the Laws for Seekers

Dear reader — Montesquieu was a French nobleman and judge who spent about twenty years writing a huge comparative study of laws and governments, published in 1748. It's enormous. This guide is selected, not complete, and I'm telling you the rule up front so nobody thinks I'm pretending: it covers about a tenth of the book, the passages the American founders actually used (the three forms of government, the size of republics, liberty and the separation of powers) plus the chapters on slavery, which show both his reach and his limits. The English is Thomas Nugent's eighteenth-century translation (I'm quoting the 1758 edition, because the wording shifts between editions), which is old enough to be public domain.

He's here because the founders cited him constantly. In Federalist No. 47, Madison calls him "the celebrated Montesquieu" and "the oracle who is always consulted and cited."

What Laws Are

"Laws, in their most general signification, are the necessary relations resulting from the nature of things."

Before Montesquieu, writers on politics tended to ask which government was best in the abstract. He asked how laws actually fit a country's climate, size, religion, customs and economy. He sorted governments into three: republics (rule by the people or part of them), monarchies (one person ruling under fixed laws) and despotisms (one person ruling without law). Each runs on a different driving principle: virtue in a republic, honor in a monarchy, fear in a despotism.

The comparative method became part of the foundation of political science. The point that institutions have to fit the people they govern is still argued about, any time someone asks whether a political system can be exported.

How Big Can A Republic Be

"It is natural to a republic to have only a small territory; otherwise it cannot long subsist."

In a large state, he thought, private interests overwhelm the common good, there are too many great fortunes, and the public good is sacrificed to a thousand considerations. Republics survive only when citizens are close enough to see the common interest. His way around it was a confederate republic, a union of small republics, which he said combines the internal advantages of a republic with the external strength of a monarchy.

This is the argument the Anti-Federalists used against the Constitution and the one Madison answers in Federalist No. 10, where he flips it: a large republic with many interests is safer. The Federalist No. 10 guide lays out both sides.

What Liberty Is

"Liberty is a right of doing whatever the laws permit; and if a citizen could do what they forbid, he would no longer be possest of liberty, because all his fellow citizens would have the same power."

He had to separate liberty from doing whatever you like, which he called license. In his account, liberty means being governed by law and safe from other people's power. A person feels free when he isn't afraid of another, and that takes a government arranged so no one needs to be.

Other traditions have stressed other parts of liberty, such as taking part in making the laws, or having the means to act on your choices. Those differences sit under a lot of present-day disagreements about what government should do.

Power Should Check Power

This is the famous one. Montesquieu's observation is that anyone given power tends to abuse it, "to prevent the abuse of power, it is necessary that by the very disposition of things power should be a check to power."

Then the rule: "When the legislative and executive powers are united in the same person, or in the same body of magistrates, there can be no liberty... Again, there is no liberty, if the power of judging be not separated from the legislative and executive powers."

Two myths to sort out. One: Montesquieu invented the separation of powers. He didn't. Aristotle, Polybius and Locke had versions of it, and Locke distinguished legislative, executive and federative powers in the Second Treatise. Montesquieu gave it its best-known form. Two: Montesquieu, or the Constitution, requires a total separation of the three branches. Madison answers that in Federalist No. 47, saying Montesquieu "did not mean that these departments ought to have no partial agency in, or no control over, the acts of each other." The Constitution's veto, confirmation and impeachment powers are overlap by design.

And there's a historians' dispute about whether Montesquieu even described the English constitution of his day accurately. The king's ministers already sat in Parliament, which is more fusion than he let on. Walter Bagehot made that point in 1867.

Strict Separation Or Fusion?

One side says strict separation, as in a presidential system: a president elected separately has his own mandate and can check the legislature, neither can dissolve the other, and the system forces compromise. The other says fusion, as in a parliamentary system: when the executive comes from and answers to the legislature, the majority can govern, voters know whom to hold responsible, and a government that loses confidence can be replaced without waiting for an election. Bagehot thought England's strength was exactly that fusion. Many stable democracies work this way, and they avoid the standoffs that sometimes paralyze the American system. Both of those are serious positions.

What He Wrote About Slavery

Book XV is the hard chapter. Montesquieu argues that slavery is against natural law. Chapter 5 starts with "Were I to vindicate our right to make slaves of the negroes, these should be my arguments," and then lists the arguments someone might make, in a tone of heavy irony, so the chapter is usually read as satire on them. Elsewhere he gives conventional explanations tying slavery to climate, saying in countries of extreme heat it was more reconcilable to reason.

Scholars still debate whether he was a consistent opponent of slavery. It matters here because the founders cited Montesquieu on liberty while many of them held people in slavery, and because abolitionists later used passages like this one.

Where To Start

Read Book XI chapter 6, and then Federalist No. 47 to see what the founders did with it. After that, Federalist No. 10 and No. 51 show the argument getting reversed and then turned into a working mechanism.