How a motive changes an act

A good end adds merit; a grievously bad motive corrupts a good act; a good motive makes an indifferent act good; acting partly for a bad end.

The works themselves ask 9 questions under this heading — see them together with their answers.

Also asked about as…

does intention matter · doing the right thing for the wrong reason · good intentions bad act (ed.)

In the index as End · Act · Goodness · Conformity of the human will with the divine will · God · Human Acts · Intention · Relation · To Praise · Actions · Delight · Habits · Idle act · Internal voluntary · Jesuits deny that end justifies means · Merit · Object of the human act · Obligation · Pleasure as motive not sinful

In the manuals

Read the manuals side by side → — each work's whole treatment in its own column

A Manual of Moral Theology for English-Speaking Countries

Thomas Slater, S.J. — 2 passages

Vol. I, Bk. I, Ch. IV, Sect. II, Point II. The End, nn. 4 & 5 (2 passages — hover a number to read it)

Moral Theology: A Complete Course (McHugh & Callan)

John A. McHugh, O.P., and Charles J. Callan, O.P.

Vol. I, Pt. I, Question II. Good and Bad Habits, n. 132 — Having considered human acts and the passions, we now pass to a consideration of the principles from which acts proceed proximately. These principles are, first, the faculties, powers or forces of the soul (such as the i… Read in context →

Commentaries on Human Acts (Commentarii de Actibus Humanis)

Gennaro Bucceroni, S.J. — 8 passages

Bucceroni, Commentaries on Human Acts, Commentary XII: On the End of Human Acts, nn. 3, 5, 6, 7, 8, 9 & 10 (8 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.

Jean-Pierre Gury, S.J.; notes by Antonio Ballerini, S.J. — 16 passages

Vol. I, Treatise on Human Acts, Ch. III, Art. II, § III. On the End, n. 31 (16 passages — hover a number to read it)

Manuale Theologiae Moralis

Dominic M. Prümmer, O.P. — 3 passages

Vol. I, Pt. I, Tr. II, Ch. III, Art. II, § 3. On the End, nn. 122, 123 & 124 (3 passages — hover a number to read it)

Summa Theologiae Moralis

Benedict Henry Merkelbach, O.P. — 47 passages

Vol. I, General Moral Theology, Treatise: On Human Acts in…, Second Part: On Human Acts…, Section A: On the Morality…, Q. V, Article III: On the End, nn. 158 & 159 (25 passages — hover a number to read it)

Vol. I, General Moral Theology, Treatise: On Human Acts in…, Second Part: On Human Acts…, Section B: On the Morality…, Question I: On the Goodness and Malice of the Interior Act, nn. ¶1, 162, 163, 164, 165, 166 & 167 (22 passages — hover a number to read it)

Compendium of Moral Theology

Aloysius Sabetti, S.J., and Timothy Barrett, S.J. — 3 passages

Vol. I, Tr. I, Ch. IV, Art. II, § III. On the End, nn. 28, 28, Q. 2 & 28, Q. 3 (3 passages — hover a number to read it)

Questions of Moral Theology

Thomas Slater, S.J. — 22 passages

Slater, Questions, Some Questions Concerning Intention, nn. ¶632, ¶633, ¶634, ¶635, ¶636, ¶637, ¶638, ¶639, ¶640, ¶641, ¶642, ¶643, ¶644, ¶646, ¶647, ¶648, ¶649, ¶650, ¶651 & ¶652 (22 passages — hover a number to read it)

Treated under the broader heading The End — Wouters, Manual of Moral Theology · Bucceroni, Institutions of Moral Theology · Bucceroni, Cases of Conscience · Tanquerey · Koch–Preuss · Vermeersch, Theologia Moralis · Billuart, Summa Summae · Rickaby, Moral Philosophy — these works do not divide the matter as finely as we do here, so their treatment stands one heading up (ed.)