The Catechism in a Year (with Fr. Mike Schmitz)

Episode: Day 256: The Natural Moral Law (2025)

Date: September 13, 2025
Host: Fr. Mike Schmitz
Reading: Catechism of the Catholic Church, Paragraphs 1949–1960

Episode Overview

This episode delves into the concept of “the natural moral law” as presented in the Catechism of the Catholic Church. Fr. Mike unpacks what the Church means by “moral law,” its roots in divine wisdom, and the unique ability of humans to participate in this law through reason. He explores how these foundational laws, written on the human heart, intersect with revealed law, civil law, and the teachings of Christ. The discussion emphasizes our calling to pursue goodness, how the law guides us, and why grace is vital for salvation.

Key Discussion Points & Insights

1. Introduction to the Moral Law and Its Structure

• Main Idea: The Catechism transitions to a new section on God’s salvation through law and grace, starting with the foundational moral law—specifically, the natural moral law.
• Clarification: The term “natural law” isn’t the same as the “law of nature” (like survival of the fittest), but refers to moral imperatives written in every human heart.
• Fr. Mike:

  “There are laws written not in some book somewhere, but written on the human heart.” [01:40]

2. We're Called to Beatitude but Wounded by Sin

• Human Condition: Humanity is made for eternal happiness with God but is wounded by sin and needs salvation.
• Role of Law and Grace: Divine help arrives via both the law (which guides) and grace (which sustains and enables us).
• Scripture Reference:

  “As St. Paul’s letter to the Philippians states, ‘Work out your own salvation with fear and trembling, for God is at work in you both to will and to work for his good pleasure.’” [05:20]

3. What is the Moral Law?

• Biblical Meaning: The moral law is a form of “fatherly instruction”—God teaching us as a loving parent.
• Definition:

  “Law is a rule of conduct enacted by competent authority for the sake of the common good.” [06:10]

• Foundation: All law finds its origin in the eternal law—God’s wisdom and providence.

4. Expressions of Moral Law

• Hierarchy and Connection:

  • Eternal Law (rooted in God as the source of all law)
  • Natural Law (in the human heart)
  • Revealed Law (Old and New Covenant)
  • Civil and Ecclesiastical Laws

• Interconnectedness: Church, state, and societal laws should reflect God-given moral law.

• Example: Human equality is rooted in theological and natural law, ideally reflected in civil and church laws.

• Quote:

  “All of them are meant to be connected. They’re meant to be coherent and consistent.” [11:45]

5. The Heart of Natural Moral Law

• What Is Natural Law?
  • The way humans, using reason, participate in God’s wisdom and goodness.
  • Internal compass—every person feels obligated to do good and avoid evil.
• Quotes from Tradition:
  • Pope Leo XIII:

    “The natural law is written and engraved in the soul of each and every man, because it is human reason ordaining him to do good and forbidding him to sin.” [14:05]

  • St. Augustine:

    “Where then are these rules written, if not in the book of that light we call the truth?... it places its imprint on it, like a seal on a ring that passes onto wax...” [16:15]

  • St. Thomas Aquinas:

    “The natural law is nothing other than the light of understanding placed in us by God. Through it we know what we must do and what we must avoid.” [17:00]

  • Cicero:

    “For there is a true law, right reason, it is in conformity with nature, is diffused among all men, and is immutable and eternal...” [18:20]

6. Features and Permanence of the Natural Law

• Universality: It applies to all people, everywhere and always.
• Immutability:

  “The natural law is immutable and permanent. Throughout the variations of history, it subsists under the flux of ideas and customs and supports their progress.” [19:50]

• Expressed in the Decalogue (Ten Commandments): The principal precepts recognized across cultures and religions.

7. Common Misunderstandings: Natural Law vs. Law of Nature

• Distinction:
  • Law of Nature: Observed behaviors in animals and the physical world (e.g., animal mothers eating their young).
  • Natural Law: Moral imperatives discerned by reason (not everything in nature is morally good).

  “Natural law is not the same thing as the law of nature. The natural law is rooted in reason and in freedom.” [22:05]

8. Challenges in Perceiving the Natural Law

• Effects of Sin: Original sin clouds human judgment; not everyone clearly or immediately perceives natural law.
• Cultural Diversity: Application can differ by time, place, and situation, but the basic precepts remain.
• Need for Grace and Revelation:

  “Sinful man needs grace and revelation, so moral and religious truths may be known by everyone with facility, with firm certainty, and with no admixture of error.” [24:35]

9. Memorable Illustrations and Modern References

• C.S. Lewis on Natural Law:
  • Using “argument” as evidence for a universal sense of right/wrong; even small acts (like trying to step on someone’s toe) reveal a belief in binding moral standards.

  “We don’t simply fight, we argue… typically we appeal to a greater law that all of us find in our hearts.” [15:35]

Notable Quotes & Moments

• Fr. Mike, On Law and Grace:

  “If anyone’s going to say that you don’t need the law or that you don’t need grace, those would be false… Both, and: we need both law and grace. The law that guides us and the grace that sustains us.” [08:10]

• On God as the Source of Law and Goodness:

  “God is the source of all good, so he commands goodness. God is the source of all life, so he commands life… God is reasonable… Therefore everything he commands is connected.” [12:30]

Timestamps for Important Segments

• [01:40] – Distinguishing “natural law” from “law of nature”
• [05:20] – Humanity’s woundedness and need for law/grace (Philippians quote)
• [06:10] – Catechism’s definition of moral law
• [11:45] – Interconnectedness of eternal, natural, revealed, civil, and church laws
• [14:05] – Pope Leo XIII on law written in the soul
• [15:35] – C.S. Lewis and the universality of moral argument
• [16:15] – St. Augustine on rules written on the heart by divine light
• [17:00] – St. Thomas Aquinas on the natural law as God-given understanding
• [18:20] – Cicero on the universality and immutability of natural law
• [19:50] – The permanence of natural law across history
• [22:05] – Highlighting the difference between natural law and law of nature
• [24:35] – Why grace and revelation are necessary for moral certainty

Conclusion & Looking Ahead

Fr. Mike summarizes that natural law is both profound and foundational—written on every heart, accessible to all, yet not always perfectly perceived due to sin and limitation. Tomorrow’s episode will move to the “old law” and its relationship to natural law, then onward to the law of the Gospel, continuing the journey of how God speaks more clearly and specifically through Revelation.

Takeaway:
At the root of Catholic moral teaching lies a set of universal precepts—natural moral law—that guides all people toward goodness, sustained by God’s grace, and made explicit in revelation through Scripture and Tradition.

End of summary.