Thomas Watson’s The Ten Commandments is the second volume of his great Body of Practical Divinity, and it is exactly what its plain title promises: a warm, searching, sentence-by-sentence walk through the moral law. But if you come to it expecting a rulebook, Watson will surprise you. He does hold the commandments up to the light and show you every angle of them — yet his whole aim in doing so is not to leave you straining to keep them, but to drive you to Christ, who kept them for you. This guide is a map of the book: what it is, how Watson handles each commandment, the great themes that run underneath, who will most profit from it, and how to read it today. Along the way we quote Watson himself, so you can hear the voice that has kept readers company for three and a half centuries. The full text is free to read on Ochorus, and this guide is meant to send you into it, not to replace it.
What the book is, and Watson’s approach
Watson (c. 1620–1686) was a London Puritan, rector of St Stephen’s, Walbrook, until he was ejected in 1662. He was famous in his own day less for learning worn on his sleeve than for putting more truth into a single sentence than most preachers managed in a page. The Ten Commandments began as sermons on the Westminster Shorter Catechism, and it keeps a preacher’s heat: every doctrine ends in application, every abstraction in a homely picture you cannot forget.
The key to the whole book is announced before Watson reaches the first commandment. The law, he says, is a mirror. Its first work is not to make us feel capable but to make us feel our need:
“It is a glass to show us our sins, that, seeing our pollution and misery, we may be forced to flee to Christ to satisfy for former guilt, and to save from future wrath.”
Thomas Watson
That sentence governs everything. Watson is following Paul, who wrote that “by the law is the knowledge of sin” (Romans 3:20) and that “the law was our schoolmaster to bring us unto Christ” (Galatians 3:24). So when Watson exposes how far short we fall, he is not tightening a noose; he is pointing to a door. The commandments show us the disease so that we will value the Physician. This is why the book is a companion to the gospel and not a rival to it, and why Watson can insist that obedience, when it finally comes, is never the ground of our acceptance. Even the best Christian, he says, shoots short of the mark:
“Not our obedience, but Christ’s merits procure acceptance.”
Thomas Watson
How Watson reads each commandment
Before treating the commandments one by one, Watson lays down rules for reading them rightly, and these rules are the engine of the whole exposition. The first is that the law reaches the heart. Quoting the great summary “Thou shalt love the Lord thy God with all thine heart” (Deuteronomy 6:5), he insists that God requires “not only the outward act of obedience, but the inward affection of love.” In his memorable rendering of an old maxim, “Man’s law binds the hands only, God’s law binds the heart.” This is precisely how Jesus read the law in the Sermon on the Mount, where an unmurdered brother can still be hated and an untouched woman still lusted after (Matthew 5).
His second rule is that each commandment says more than it seems to say — “In the commandments there is a synecdoche, more is intended than is spoken.” From this he draws a pattern that shapes every chapter:
- Where a duty is commanded, the opposite sin is forbidden — the command to keep the Sabbath holy forbids profaning it.
- Where a sin is forbidden, the opposite duty is commanded — the ban on taking God’s name in vain requires that we reverence it.
- Where a sin is forbidden, its occasions are forbidden too — “Where murder is forbidden, envy and rash anger are forbidden, which may occasion it.”
So Watson treats every commandment in two movements: the duties it requires and the sins it forbids. Under the first commandment he unfolds what it means to have God as our God; under the third, both the reverencing and the profaning of his name; under the sixth, not only murder but the anger and malice that breed it; under the eighth, both honest labour and every kind of theft. He divides the ten across the two tables Jesus named — love of God and love of neighbour (Matthew 22) — and refuses to let a reader keep one table while breaking the other: “A good Christian makes gospel piety and moral equity kiss each other.” The effect is bracing. By the time Watson has read a single commandment down into the heart and out into all its occasions, no honest reader is left thinking of himself as a keeper of the law.
Central themes: the use of the law, and law and gospel
The deepest current in the book is the right relation of law and gospel, and Watson holds it with unusual care. He distinguishes them plainly: “The law requires that we worship God as our Creator; the gospel, that we worship him in and through Christ.” He is equally plain that the believer is no longer under the law as a way of salvation. Christ has borne its curse — “Christ has redeemed us from the curse of the law, being made a curse for us” (Galatians 3:13) — so the law can neither justify nor condemn the one who is in him.
But Watson will not let this good news curdle into lawlessness. The law, abolished as a covenant, remains as a rule:
“Though it be not their Saviour, it is their guide.”
Thomas Watson
Against those of his day who wanted the moral law abrogated altogether, he writes one of his most quoted lines — a sentence that guards the gospel by refusing to divorce it from holiness:
“They who will not have the law to rule them, shall never have the gospel to save them.”
Thomas Watson
This is the opposite of moralism. Moralism makes obedience the price of God’s favour; Watson makes it the fruit of it. The order matters enormously. Because acceptance is already secured by Christ’s merits, obedience can at last be free, glad, and heartfelt rather than anxious. Watson prizes willing obedience above the grudging kind — “God sometimes accepts of willingness without the work, but never of the work without willingness” — and warns that a religion of outward performance without the heart is worthless: “Cain brought his sacrifice, but not his heart.” He even ties knowledge and obedience together as two halves of one life: “Obedience without knowledge is blind, and knowledge without obedience is lame.”
The book’s architecture makes the argument for you. After the commandments Watson turns to our total inability to keep them, then to the degrees of sin and the wrath of God (a chapter that lets the mirror do its full work), and only then to faith, repentance, the Word, the sacraments, and prayer. In other words, the law empties our hands so that faith can be filled. When he finally reaches faith he crowns it above every other grace for this one reason:
“Other graces help to sanctify us, but faith only has the honour to justify us.”
Thomas Watson
He leans on the same texts Protestants have always leaned on — “the just shall live by his faith” (Habakkuk 2:4), Christ “set forth to be a propitiation through faith in his blood” (Romans 3:25), “this is the victory that overcometh the world, even our faith” (1 John 5:4). And he presses the danger of the opposite: “He that believeth not on the Son of God, the wrath of God abideth on him” (John 3:36). Law and gospel, held together, end where Watson wants every reader to end — resting on Christ.
Who should read it
This book is for a wider circle than its Puritan pedigree might suggest. It is for the new believer who wants to know what a holy life actually looks like and keeps mistaking rules for relationship — Watson will show you the shape of obedience without ever letting you make it your saviour. It is for the mature Christian who has grown slack, and needs the mirror held up again. It is for anyone burdened by guilt or by perfectionism, because Watson relentlessly redirects the anxious heart from its own performance to Christ’s merits. It is for preachers and teachers, who will find here a model of how to move from text to conscience to Christ. And it is for the curious reader of Scripture who has always wanted a patient, thorough exposition of the Decalogue by a master of the plain, vivid sentence. Because Watson always ends in application, even his heaviest chapters leave you with something to do and someone to trust.
How to read it today
A few habits will make the book far more rewarding.
- Read the front chapters first, and slowly. The opening pieces on obedience, love, the preface to the commandments, and the right understanding of the law are the lens for everything after. Skip them and the individual commandments can read like moralism; keep them and the whole book breathes grace.
- Take one commandment at a time. Each chapter is self-contained. Read the duties it requires and the sins it forbids, then pause and let the mirror do its work before moving on.
- Let it drive you to Christ, not to despair. When Watson shows you how far you fall short, that is the schoolmaster of Galatians 3:24 at work. The right response is not resolve but repentance and renewed faith. Read the closing chapters on faith and repentance as the destination the whole book is aiming at.
- Keep a Bible open. Watson quotes constantly; read his proof-texts in their own context, from Exodus 20 to the Sermon on the Mount, and the exposition comes alive.
- Mind the older English. A few Latin tags and seventeenth-century idioms appear, but Watson is one of the most readable of the Puritans; a slightly slower pace is all most readers need.
You can read the whole of The Ten Commandments free on Ochorus, and browse the rest of Thomas Watson’s writings alongside it.
For reflection
Use these questions on your own or with a group, ideally with the book open beside you.
- Watson calls the law “a glass to show us our sins” that we may “flee to Christ.” When you measure yourself against the commandments, does the result push you toward despair, toward self-improvement, or toward Christ — and why?
- “Man’s law binds the hands only, God’s law binds the heart.” Where are you tempted to be content with outward conformity while the inward affection is missing?
- Watson says the moral law is “not their Saviour” but “their guide.” How does obeying out of gratitude for grace differ, in practice, from obeying to earn acceptance?
- “God sometimes accepts of willingness without the work, but never of the work without willingness.” What would change if you pursued glad obedience rather than dutiful performance this week?
- Reading the commandment that most exposes you, what is the specific duty required and sin forbidden — and what would repentance and renewed faith in Christ look like there?
