The Nature of the Moral Law

Are the Precepts of the Decalogue Natural and Indispensable?

We affirm that they are.

Excerpts of Francis Turretin

Francis Turretin teaches that the Ten Commandments are not temporary rules given only to Israel, nor are they merely positive laws that could be changed or removed. Rather, they are natural, moral laws—rooted in God’s own character and written into human nature itself.

1. The Moral Law Is Natural

The commandments of the Decalogue flow from the very nature of God and from the way He created human beings. They are called natural because they are:

• Known by the light of reason

• Written on the human heart

• Recognized by all people, in all places, at all times

Even those without Scripture still understand, at least in part, that God should be worshiped, parents honored, life protected, marriage respected, property not stolen, truth upheld, and inward desires governed.

Romans 2:14–15 — The law is “written on their hearts.”
Ecclesiastes 12:13 — This is “the whole duty of man.”

2. The Moral Law Is Indispensable

Turretin insists that the moral law is unchangeable and binding. It cannot be repealed because it is grounded in:

• God’s holiness

• God’s justice

• God’s immutable will

If God were to abolish the moral law, He would be denying His own nature—which is impossible.

Malachi 3:6 — “I the LORD do not change.”
Psalm 119:160 — God’s righteous rules endure forever.

3. The Moral Law Is Not Ceremonial or Civil

Unlike ceremonial laws (sacrifices, dietary laws, temple rituals) and civil laws (Israel’s judicial system), the Decalogue:

• Existed before Moses

• Applies to all nations

• Continues after Christ’s resurrection

Christ fulfilled the ceremonial law, but He confirmed and upheld the moral law.

Matthew 5:17–19 — Christ did not abolish the Law but fulfilled it.
Romans 3:31 — Faith does not overthrow the law but establishes it.

4. The Moral Law Still Binds Believers

Turretin is clear: believers are not under the moral law as a way to earn salvation, but they are under it as a rule of life.

The law:

• Reveals God’s will

• Exposes sin

• Guides grateful obedience

Grace does not cancel obedience; it produces it.

John 14:15 — “If you love me, you will keep my commandments.”
Titus 2:11–12 — Grace trains us to live godly lives.

5. Summary (Turretin’s Affirmation)

• The Decalogue is natural, not invented by Moses.

• It is indispensable, not temporary.

• It is unchangeable, not adaptable to culture.

• It is universal, not limited to Israel.

• It is binding, not as a means of justification, but as a rule of obedience.

Conclusion:
According to Francis Turretin, the precepts of the Ten Commandments are laws of natural and indispensable right—flowing from God’s nature, written on the human heart, and permanently binding on all people, including believers under the gospel.