A Topic of Moral Theology

Lying always unlawful

Never justified, even to save life; the gravity of lies.

Also asked about as…

is a white lie a sin · lying for a good reason · lying to protect someone (ed.)

In the index as Lying · Lie · Mental restriction · Dissimulation of truth · Lies (see Lying) · Amphibology · Cattaneo, Ambrogio · Equivocation · Basil, St. · Casuists · Cause · Clement of Rome · Deceit · False speaking · False testimony · God · Grotius and Milton · Hermas · Hypocrisy · John the Evangelist, St. · Justin Martyr, St. · La Croix, Claude · Language · Loquacity

In the manuals

A Manual of Moral Theology for English-Speaking Countries

Vol. I, Bk. VI, Pt. VIII, Chapter IV. Lying, n. 2 — According to the common Catholic teaching, lying of every kind is intrinsically wrong; so that, inasmuch as we may not do evil that good may come of it, we are never justified in telling a lie, not even if the life of an… Read in context →

Moral Theology: A Complete Course (McHugh & Callan)

Vol. II, Pt. II, Q. II, Art. 6. The Remaining Potential Parts of Justice; the Gift of Piety; the Commandments, Lying, nn. 2389, 2390, 2391, 2392, 2393, 2394, 2395, 2396 & 2397 (9 passages — hover a number to read it)

Compendium of Moral Theology of Fr. John Peter Gury, S.J., with the Notes of Antonio Ballerini, S.J.

Vol. I, Treatise On the Precepts o…, On the Eighth Precept of t…, Ch. I, Article I. On Lying in General, n. 439 (3 passages — hover a number to read it)

Synopsis of Moral and Pastoral Theology

Vol. III, Contracts, and the Obligat…, On the Virtue of Justice (…, Part I — Chapter II: On Injury, or the Violation of Right, nn. 405, 406, 407, 408, 409, 410, 411, 412, 413, 414, 415, 416 & 417 (13 passages — hover a number to read it)

A Handbook of Moral Theology (Koch–Preuss)

Vol. V, Pt. I, Ch. II, Section 5: The Sin of Lying, nn. ¶12–¶27 (16 passages)

Manuale Theologiae Moralis

Vol. II, Tr. XI, Sect. I, Q. III, Ch. III, Art. IV, II. On Injuries By Words O…, § 2. On Lying, nn. 169 & 170 (2 passages — hover a number to read it)

Summa Theologiae Moralis

Vol. II, Special Moral Theology: On…, Treatise: On the Cardinal …, Fifth Part: On the Virtues…, Section E: On Truth, Question Three: On Lying, Article I: On Lying Itself, nn. ¶1, 857, 858, 859, 860, 861, 862 & 863 (32 passages — hover a number to read it)

Compendium of Moral Theology

Vol. I, Tr. VI, On the Eighth Precept of t…, Chapter I. On Lying and Mental Restriction, n. 312 — I say 1st. A lie properly so called is certainly something intrinsically evil, but does not exceed venial sin if it is jocose, or even officious; but if it is harmful, it will be a light or grave sin according to the qua… Read in context →

Christian Theology, Dogmatic and Moral, Volume III: On the Decalogue

Diss. III, Equivocal, Ambiguous, and Amphibologi…, Ch. I, Origen, Hilary, John Chrysostom, Cassian, John Climacus, and Martin of Braga, concerning the licit use of a lie in extreme necessity, are reviewed, nn. I, II, III, IV, V, VI, VII, VIII & IX (9 passages — hover a number to read it)

Diss. III, Equivocal, Ambiguous, and Amphibologi…, Ch. II, Augustine's time, declared war on lying, are recounted. After Augustine, none of the Catholics favored lying, nn. I, II, III, IV & V (5 passages — hover a number to read it)

Diss. III, Equivocal, Ambiguous, and Amphibologi…, Chapter III — A compendious narration of everything that St. Augustine writes in his Book on Lying, nn. I, II, III, IV, V, VI, VII, VIII, IX, X, XI, XII & XIII (13 passages — hover a number to read it)

Diss. III, Equivocal, Ambiguous, and Amphibologi…, Chapter IV — A compendium of the Book Against Lying, which St. Augustine wrote to Consentius, nn. I, II, III, IV, V, VI, VII, VIII & IX (9 passages — hover a number to read it)

Diss. III, Equivocal, Ambiguous, and Amphibologi…, Chapter V — How opportune Augustine's teaching is for settling the controversy concerning the deceitful oath will be made plain from the following propositions, nn. I, II, III, IV, V, VI, VII, VIII & IX (9 passages — hover a number to read it)

Diss. III, Equivocal, Ambiguous, and Amphibologi…, Chapter XII — The opinion of Fr. Cattaneo, of Fr. La Croix, and of a few other authors, who compare a lie with a theft committed in extreme necessity, does not seem consonant with the teaching of the Church, nn. I–XV (15 passages)

Diss. III, Equivocal, Ambiguous, and Amphibologi…, Chapter XVIII — The texts of Sacred Scripture which the ancients oppose in defense of lies, and more recent writers in defense of mental restrictions, are expounded, nn. I, II, III, IV, V, VI, VII & VIII (8 passages — hover a number to read it)

Palladium Theologicum, Tome V: On the Virtues

Tr. IV, Disputation XIII: On the O…, Sect. V, Friendship, Liberality, Epikeia, and the Opposed V…, Q. II, Doubt III: Whether every lie is intrinsically a sin, nn. 1–36 (36 passages)

Tr. IV, Disputation XIII: On the O…, Sect. V, Friendship, Liberality, Epikeia, and the Opposed V…, Q. II, Doubt IV: Whether a lie is mortal of its kind, nn. 1–19 (19 passages)

Tr. IV, Disputation XIII: On the O…, Sect. V, Friendship, Liberality, Epikeia, and the Opposed V…, Q. II, Doubt V: Whether every lie is mortal for perfect men, nn. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 & 11 (11 passages — hover a number to read it)

Tr. IV, Disputation XIII: On the O…, Sect. V, Friendship, Liberality, Epikeia, and the Opposed V…, Q. II, Doubt VI: Whether among the degrees of lying there is a gravest and a lightest, nn. 1–19 (19 passages)

Moral Philosophy: Ethics, Deontology and Natural Law

Pt. III, Ch. III, Section II. Of the Evil of Lying, nn. 1, 2, 3, 4, 5, 6, 7 & 8 (8 passages — hover a number to read it)

The Catechism of the Council of Trent (The Roman Catechism)

Pt. III, The Eighth Commandment, nn. ¶24, ¶25, ¶44, ¶45, ¶46, ¶47, ¶48, ¶49 & ¶50 (9 passages — hover a number to read it)

A Brief Text-Book of Moral Philosophy

Chapter IV: Our Rights and Duties Towards Our Fellow-men, nn. 156, ¶299, ¶300, ¶301, 157, ¶303, ¶304, ¶305 & ¶306 (9 passages — hover a number to read it)

Guide for Catholic Young Women

Chapter LXXI: Scripture on Lying, nn. ¶860, ¶861, ¶862, ¶863, ¶864, ¶865, ¶866 & ¶867 (8 passages — hover a number to read it)

Chapter LXXII: The Devil’s Pretexts for Lying, nn. ¶868–¶882 (15 passages)

Chapter LXXIII: Examples of Truthfulness, nn. ¶883, ¶884, ¶885, ¶886, ¶887, ¶888 & ¶889 (7 passages — hover a number to read it)

Treated under the broader heading Lying and Mental Reservation — Wouters, Manual of Moral Theology · Bucceroni, Institutions of Moral Theology · Vermeersch, Theologia Moralis · Konings, Theologia Moralis · Marc, Institutiones Morales · The Casuist · Spirago — these works do not divide the matter as finely as we do here, so their treatment stands one heading up (ed.)