· Summa I-II & II-II
Moral Theology
The science of human acts ordered to the supernatural end. Conscience, law, sin, the virtues and vices, the Decalogue, the precepts of the Church. Tanquerey, Alphonsus Liguori, and Aquinas's Secunda Pars form the principal sources.
Primary Texts
42 chaptersIntroduction
Table of contents and overview
The Last End of Man
Existence of the Last End; Nature of the Last End; Attainment of the Last End.
Acts as Human
Definition; Knowledge Requisite for a Human Act; Effects of Concomitant, Consequent, and Antecedent Ignorance; Effects of Invincible and Vincible Ignorance; Consent Requisite for a Human Act; Kinds of Voluntary Acts; Obstacles to Consent; Habits; Two Kinds of Voluntary Acts.
Acts as Moral
Definition; The Sources of Morality; Good Acts; Bad Acts; Indifferent Acts; Morality of the External Act; The Morality of the Act That Is Indirectly Willed; The Morality of the Consequences of an Act; Imputability.
Acts as Meritorious
Definitions; Divisions; The second kind of merit mentioned above; The objects of condign merit.
The Passions
Definition; Division; Moral Value of the Passions.
Habits in General
Definition; Division; Strengthening and Weakening of Habits; Habits and Morality; Duties as regards Habits.
Good Habits, or Virtues
Definition; Division; Causes of Virtues; Properties of the Virtues; The Complements of the Virtues.
Bad Habits, or Vices
Definition; Divisions; Mortal Sin; Venial Sin; Imperfections; Change in the Gravity of Moral Defects; The Distinction of Sins; First Rule of Numerical Distinction; Second Rule of Numerical Distinction.
Law in General
Definition; Division; Collision of Laws; Since rights and duties are correlative; The Basis of All Laws.
The Natural Law
Meaning; Relation of the Natural Law to Other Laws; Division; Properties; Interpretation.
The Positive Divine Law
Meaning; Division; The Mosaic Law; The Excellence of the Mosaic Law; The Subjects of the Mosaic Law; The Duration of the Mosaic Law; The Law of the New Testament; Comparison of the Two Testaments from Other Viewpoints; Differences in the Precepts of the Two Laws.
Human Law
Definition; Division of Human Laws; Qualities; Obligation of Human Laws; Interpretation; Those Subject to Law; Change of Law; The Law of Custom; Dispensation.
Ecclesiastical Law
General Law of the Church; Lawgivers in the Church; Subject-Matter of Church Law; Those Bound by General Laws; Those Bound by Particular Laws; Promulgation; Fulfillment of Law; Interpretation; Rules for Doctrinal Interpretation.
Civil Law
Meaning; Origin; Subject-Matter; Those Subject to Civil Law; The Obligation of Civil Law; Special Kinds of Laws.
The Law of Conscience
Definition; Division; Obligation of Conscience; Exception; Results of Conscience.
A Good Conscience
Definition; Divisions; The Lax Conscience; Causes of a Lax Conscience; Special Dangers of a Lax Conscience; Remedies Recommended for a Lax Conscience; The scrupulous Conscience; Special Dangers of a scrupulous Conscience; The Perplexed Conscience.
A Certain Conscience
Necessity of Certitude; Kinds of Certitude; An Uncertain Conscience; Doubt and Suspicion; Opinion; The Moral Systems; Tutiorism; Laxism; Probabiliorism.
The Virtue of Faith
Excellence of the Virtue of Faith; Utility of Faith for the Individual; Utility of Faith for Society; The Meaning of Faith; The Object of Faith; The Acts of Faith; The Habit of Faith; The Gifts of Understanding and Knowledge.
The Sins against Faith
The Sin of Unbelief; Heresy; Various Kinds of Heresy; Apostasy; The Sin of Doubt; Credulity and Rationalism; Dangers to Faith; Dangerous Reading; Dangerous Schools.
The Commandments of Faith
The Commandment of Knowledge; The Commandment of Internal Acts of Faith; The Commandment of External Profession of Faith; Dangers of Profession of Unbelief; Forbidden Societies; Absolution of Those Who Belong to Forbidden Societies; Communication in Worship; Cooperation in Religious Activities.
The Virtue of Hope
Definition; The Object of Hope; The Excellence of Hope; Comparison of Hope with Faith; Comparison of Hope with Charity; The Subject of Hope; The Gift of Fear of the Lord; The Sins Against Hope; Since hope has many elements of which it is composed, despair.
The Virtue of Charity
Definition; The Excellence of Charity; Production of Charity; The Origin of Charity; The Decline of Charity; The Loss of Charity; The Object of Charity; Charity for Sinners; Association with Sinners.
The Effects of Charity
Internal Effects of Charity; Peace; Mercy; Mercy Compared with the Other Moral Virtues; Mercy Compared with Charity; The Obligation of Mercy; External Effects of Charity; Beneficence; Almsgiving.
The Sins against Love and Joy
Hate; Hatred of God; Hatred of God as a Special Sin; The Gravity of Hatred of God; Degrees of Malice in Hatred of God; Hatred of Creatures; Gravity of the Sin of Hatred of Neighbor; Hatred Compared with Other Sins Against the Neighbor; Various Species of the Sin of Hatred.
The Sins against Peace
Discord; Sinfulness of Intentional Discord; Sinfulness of Unintentional Discord; The Origin of Discord; Contention; The Sin of Contention; The Causes of Sinful Contention; Schism; The Principal Schismatical Movements.
The Sins against Beneficence
Scandal; Definition of Scandal; Causes of Scandal; Obscenity; Persons Who Give Scandal on Account of Obscenity; Results of Scandal; Sinfulness of Scandal; Practical Applications of the Preceding Paragraph to Confession; The Gravity of the Sin of Scandal.
The Commandments of Charity
The Commandment of Love of God; The Commandment of Love of Self; Examples of Sins Committed by Neglect of Necessary Education; Confession of Sins against Charity Owed to Self; The Commandment of Love of Neighbor; Fulfillment of the Commandments of Charity; The Intention of Performing All Good Works out of Love for God; Applications of the Preceding Paragraph; The precept of love of God obliges directly.
The Gift of Wisdom
The Nature of the Gift of Wisdom; The Persons Who Possess Wisdom; The Exercise of the Gift of Wisdom; The Beatitude and the Fruits that Correspond to Wisdom; The Sins Opposed to Wisdom.
The Virtue of Prudence
Definition; The Objects of the Act of Prudence; Necessity of Certitude; Relation of Prudence to the Other Moral Virtues; The Exercise of Prudence; Qualities of Prudence; The Parts or Kinds of Prudence; Integral Parts of Prudence; The Subjective Parts or Species of Prudence.
The Virtue of Justice
Nature of Justice; Definition of Right; Divisions of Right; Signs by which Strict and Non-Strict Rights May Be Distinguished; Legal Enforcement of Strict Rights; The Subject of Justice, or the Faculty of the Soul in Which It Exists; The Objects or Subject-Matter of Justice; Division of Justice; Comparison of Legal and Particular Justice.
The Subjective Parts of Justice: Distributive and Commutative Justice
The Three Species of Justice; Resemblance between Distributive and Commutative Justice; The Special Differences between Distributive and Commutative Justice; Commutations of Commutative Justice; Forms of Contract; The Equality Sought by Commutative Justice; Restitution; Differences between Satisfaction and Restitution; When Restitution Is Due.
The Vices Opposed to Commutative and Distributive Justice
The Vice Opposed to Distributive Justice; The Sinfulness of Favoritism from Revelation; The Sinfulness of Favoritism from Reason; The Gravity of the Sin of Favoritism; Favoritism in Spiritual Matters; Opinion of the Applicant or Appointee about His Own Fitness; Favoritism in Secular Matters; Favoritism in Marks of Esteem or Honor Shown to Others; Favoritism in Judges (Umpires, Arbitrators) and the Like.
The Quasi-Integral and Potential Parts of Justice; the Virtue of Religion and the Opposite Vices
The Quasi-Integral Parts of Justice; The Potential Parts of Justice; Degrees of Moral Debt; Epieikeia; The Virtue of Religion; Religion as a Moral Virtue; Superiority of Religion as a Virtue; Necessity of the Acts of Religion; The Internal Acts of Religion.
The Remaining Potential Parts of Justice; the Gift of Piety; the Commandments
The Virtue of Piety; Definition of Piety; The Reverence Required by Piety; The Assistance Required by Piety; Sins against Piety; Malice of Sins against Piety; The Virtue of Reverence; Species of Honor; Obligation of Showing Honor to Deserving Excellence.
The Virtue of Fortitude
The Virtue of Fortitude; Fortitude in General; Definition of Fortitude; The Two Acts of Fortitude; The Excellence of Fortitude; Martyrdom; Kinds of Martyrdom; Conditions for Martyrdom; Practical Questions about Martyrdom.
The Virtue of Temperance
Definition of Temperance; The Rule of Moderation; The Excellence of Temperance; The Vices Opposed to Temperance; The Parts of Temperance; Abstemiousness; Degrees of Abstemiousness; Austerity; The Excellence of Fasting and Abstinence.
The Duties of Members of the Church
The General Duties of the Faithful; The First Precept of the Church; The Affirmative and Negative Parts of the First Precept; How Mass Must Be Heard; Time and Place of Mass; Servile Works; Other Kinds of Works and Sunday Observance; Obligation of First Precept; Excuses from Observance of First Precept.
Duties of Members of Domestic and Civil Society
The Duties of Husbands and Wives; The Obligation of Paying the Conjugal Debt; Absence of Obligation; Suspension of Obligation; Is There an Obligation of Requesting Conjugal Intercourse?; The Morality of Venereal Acts of Marriage; Nota; Contraception; Some Arguments of Neo-Malthusians and Other Advocates of Contraception.
The Sacraments in General; the Sacramentals
Nature of a Sacrament; Rules on the Invalid Use of the Matter and Form of the Sacraments; Simultaneity of Matter and Form; Accidental Changes or Separations as to Matter and Form; Substantial Changes or Separations; Doubtful Matter; What Sacraments Have a Necessity of Means (see 360, 786, 2156)?; Reception of Sacraments *in re* or *in voto*; What Sacraments Have a Necessity of Precept?.
Baptism; Confirmation; the Eucharist; the Sacrifice of the Mass
The Sacrament of Baptism; Solemn and Private Baptism; Duties of Parish-Priests as to Baptism; Duties of Parents and Guardians in Reference to Baptism; Sponsors; Duties of Sponsors; Duties of the Minister of Baptism; The Sacrament of Confirmation; The Minister of Confirmation.
Repentance; Penance; Extreme Unction
The Virtue of Repentance; Repentance; The Character of Repentance; The Excellence of Repentance; Is Repentance Necessary as a Means or as a Precept?; How Soon Does the Precept of Repentance Oblige?; Accompaniments of Repentance as to Mortal Sin; The Fruits of Repentance; Forgiveness of Sin through the Use of the Sacraments.
Holy Orders; Matrimony
The Sacrament of Orders; Distinction of the Orders; The Hierarchy of Orders and Jurisdiction; The Matter and Form of the Various Orders in the Latin Church; The Minister of Ordination; The Special Duties of the Minister; The Recipient of Orders; Canonical Requirements for Ordination; Duties of Ordinandi According to Canon Law.
Glenn's Tour of the Summa
277 questionsGlenn's chapter-by-chapter précis of the Summa Theologica, with links to the full Latin–English text at New Advent.
Q.1 The End Man Seeks Q.2 Where Happiness is Found Q.3 What Happiness Is Q.4 Requisites for Happiness Q.5 The Attainment of Happiness Q.6 Voluntariness Q.7 Circumstances of Human Acts Q.8 Volition and Its Object Q.9 What Moves the Will Q.10 How the Will is Moved Q.11 Fruition or Enjoyment Q.12 Intention Q.13 Election or Choice of Means Q.14 Counsel Q.15 Consent Q.16 Use Q.17 Commanded Acts of the Will Q.18 Moral Good and Evil in Human Acts Q.19 Morality in Acts of the Will Q.20 Good and Evil in External Acts
Browse all 277 Tour questions for this tract →
Magisterial Documents
20Rerum Novarum
The founding document of Catholic social teaching — addressing the condition of workers, the right to private property, the just wage, and the proper roles of the state, the Church, and voluntary associations.
Casti Connubii
Reaffirms the sanctity and indissolubility of Christian marriage, condemns contraception, sterilisation, and eugenics, and establishes the doctrinal framework that Humanae Vitae later presupposes.
Quadragesimo Anno
Develops Leo XIII's social teaching forty years on — introducing the principle of subsidiarity, critiquing both unrestrained capitalism and socialism, and proposing a reconstruction of the social order.
Pacem in Terris
John XXIII's encyclical on establishing universal peace in truth, justice, charity and liberty: the order of rights and duties between persons, between citizens and public authority, between states, and in the world community. The first encyclical addressed to all people of good will.
Dignitatis Humanae
Vatican II's Declaration on Religious Freedom: the right of every person to immunity from coercion in religious matters, grounded in human dignity, while the moral duty to seek the truth and embrace the true religion remains intact.
Gaudium et Spes
Vatican II's Pastoral Constitution on the Church in the Modern World: the dignity and vocation of the human person revealed in Christ, and the Church's teaching on marriage, culture, economic life, political community and peace.
Populorum Progressio
Paul VI's encyclical on the development of peoples: integral human development of the whole person and of every person, the social limits of property, the dangers of unbridled liberalism and of revolution, and solidarity between rich and poor nations.
Humanae Vitae
Reaffirms the Church's constant teaching that every act of marital intercourse must remain open to the transmission of life, prohibiting artificial contraception.
Familiaris Consortio
John Paul II's apostolic exhortation following the 1980 Synod of Bishops on the role of the Christian family: God's plan for marriage and the family, its four tasks, the teaching of Humanae Vitae, and pastoral care in difficult situations.
Laborem Exercens
John Paul II's encyclical on human work, for the ninetieth anniversary of Rerum Novarum: work in its objective and subjective senses, the priority of labour over capital, the rights of workers and unions, the indirect employer, and a spirituality of work.
Donum Vitae
The Congregation for the Doctrine of the Faith's instruction on respect for human life in its origin and on the dignity of procreation: the respect owed to the human embryo, and the moral evaluation of artificial fertilisation, both heterologous and homologous.
Centesimus Annus
Written for the centenary of Rerum Novarum after the fall of Communism: the anthropological error of socialism, private property and the universal destination of goods, the free economy within a juridical and moral framework, democracy grounded in truth, and the critique of consumerism.
Veritatis Splendor
Provides the philosophical and theological foundations for Catholic moral theology — defending intrinsically evil acts, the objectivity of the moral law, and the inseparability of freedom and truth against proportionalism and consequentialism.
Evangelium Vitae
John Paul II's encyclical on the value and inviolability of human life, with solemn confirmations of the Church's teaching on the killing of the innocent, abortion and euthanasia, and a call to build a culture of life.
Deus Caritas Est
Benedict XVI's first encyclical, on Christian love: the unity of eros and agape in creation and salvation history, God's love revealed in Christ, the inseparability of love of God and neighbour, and the Church's charitable activity as an expression of that love.
Dignitas Personae
The Congregation for the Doctrine of the Faith's instruction on certain bioethical questions: it confirms Donum Vitae and applies its principles to newer techniques, including embryo freezing, preimplantation diagnosis, cloning, gene therapy, stem cell research and the use of biological material of illicit origin.
Caritas in Veritate
Benedict XVI's social encyclical on integral human development in charity and truth: charity as the heart of social doctrine, the legacy of Populorum Progressio, gratuitousness and the logic of gift in economic life, the link between life ethics and social ethics, and the challenge of technology.
Laudato Si'
Francis's encyclical on care for our common home: the ecological crisis and its human roots in the technocratic paradigm, the Gospel of creation, integral ecology, and the call to ecological conversion.
Fratelli Tutti
Francis's encyclical on fraternity and social friendship: the parable of the Good Samaritan as a model for society, the universal destination of goods, a better kind of politics, dialogue, forgiveness and peace, the rejection of war and the death penalty, and the service of religions to fraternity.
Magnifica Humanitas
Leo XIV's first encyclical, on safeguarding the human person in the time of artificial intelligence: the dignity of the person as the criterion for judging technology, the limits of AI, the rejection of transhumanism, and truth, work, freedom and peace in a culture of power.
Philosophical Foundation
Catholic Philosophy
Ethics
Moral theology builds on ethics — the natural law, the virtues, the human good. Glenn's Ethics presents the philosophical foundation.