painting of St. Thomas

• You will notice many references to the on-line text viewer of the Aquinas Institute below; the Institute’s video tutorial shows how to make the most of its search feature. The Institute is also in the process of making its editions available for various e-readers. •

©1998–2022, Thérèse Bonin. Last revised on ; more revisions are on the way. Please send suggestions, addenda, or corrigenda to bonin@duq.edu. For the most part, and especially in the case of the more readily available texts, extracts are noted only in the absence of complete translations. URL: aquinas-in-english.neocities.org. Made with GNU Emacs.

Theological syntheses

Scriptum super libros Sententiarum

  • Baldner, Steven E., and William E. Carroll, trans. Aquinas on Creation: Writings on the ‘Sentences’ of Peter Lombard—Book 2, Distinction 1, Question 1. Mediaeval Sources in Translation, 35. Toronto: Pontifical Institute of Mediaeval Studies, 1997.
  • Kwasniewski, Peter A., trans. ‘The Holy Spirit as Love’ and ‘Concerning the Eucharist.’ E-text, hosted.desales.edu/w4/philtheo/loughlin/ATP/index.html.
    (Latin and English. Book 1, d. 10 and book 4, d. 8, q. 1.)
  • Kwasniewski, Peter A., Thomas Bolin and Joseph Bolin, trans. On Love and Charity: Readings from the Commentary on the Sentences of Peter Lombard. Thomas Aquinas in Translation. Washington, D.C.: The Catholic University of America Press, 2008.
    (All texts on love and charity from the Commentary on the Sentences—book 1, distinction 17 in both the Parisian and Roman versions [the Lectura Romana]; book 3, distinctions 27 to 32; and selected articles from all four books—accompanied by textual and interpretive notes.)
  • Laumakis, John, trans. ‘Whether There Is Only One God,’ ‘Concerning Man’s Knowledge of God,’ ‘Whether God Is Entirely Simple,’ ‘Concerning God’s Existence in Things’ and ‘Concerning God’s Omnipresence.’ E-text, hosted.desales.edu/w4/philtheo/loughlin/ATP/index.html.
    (Latin and English. Book 1, d. 2, q. 1, a. 1; d. 3, q. 1; d. 8, q. 4, a. 1; d. 37, qq. 1–2.)
  • Loughlin, Stephen, trans. ‘Concerning the Sin against the Holy Spirit’ and ‘Concerning Fasting.’ E-text, hosted.desales.edu/w4/philtheo/loughlin/ATP/index.html and isidore.co/aquinas/Sentences.htm.
    (Latin and English. Book 2, d. 43, q. 1; book 4, d. 15, q. 3.)
  • Macierowski, E.M., trans. Thomas Aquinas’s Earliest Treatment of the Divine Essence: ‘Scriptum super libros Sententiarum,’ Book 1, Distinction 8. Medieval Studies Worldwide; Episteme. Binghamton, N.Y.: Center for Medieval and Renaissance Studies and Institute for Global Cultural Studies, Binghamton University (State University of New York), 1998.
    (Includes facing Latin text.)
  • McDermott, Timothy, trans. ‘How we Know One Simple God by Many Concepts’ and ‘God as Goal of Human Living.’ In Thomas Aquinas, Selected Philosophical Writings, selected and translated by Timothy McDermott, 230–40 and 315–41. World’s Classics. Oxford: Oxford University Press, 1993.
    (Book 1, d. 2, q. 1, a. 3, and book 4, d. 49, q. 1, both incomplete.)
  • McDonald, Hugh, trans. On the First Book of the Sentences, prologue and question 1, articles 1–5. E-text, web.archive.org/web/20170119090738/http://hyoomik.com/aquinas/sent1.html.
    (Latin and English.)
  • McDonald, Hugh, trans. Commentary on Sentences II, distinction 44, question 2, article 2. E-text, web.archive.org/web/20170119045222/http://hyoomik.com/aquinas/regicide.html.
    (Latin and English.)
  • McInerny, Ralph, trans. ‘The Nature of Theology: Commentary on Sentences 1, Prologue,’ and ‘The Work of the Six Days of Creation: Commentary on Sentences 2.2, d. 12.’ In Thomas Aquinas, Selected Writings, edited and translated with an introduction and notes by Ralph McInerny, 51–104. Harmondsworth: Penguin, 1998.
  • Molloy, Michael P., trans. ‘Excerpts from the Commentary of Thomas Aquinas: Commentary on the Second Book of the Sentences of Master Peter Lombard, Distinction 44.’ In Civil Authority in Medieval Philosophy: Lombard, Aquinas and Bonaventure, 143–73. Lanham, Md.: University Press of America, 1985.
  • Mortensen, Beth, trans. Commentary on the Sentences, Book IV, 1–13. Lander, Wyo.: The Aquinas Institute, 2017. E-text, aquinas.cc.
    (Latin and English. This is the first volume of what will be a complete translation.)
  • Penner, Sydney, trans. ‘Whether everyone desires happiness.’ E-text, www.sydneypenner.ca/ot/Sent_IV_49_1_3.pdf.
    (Latin and English. Book 4, d. 49, q. 1, a. 3.)
  • Taylor, Richard C., trans. ‘Whether the intellective soul or intellect is one in all human beings’ and ‘Whether the human intellect is able to attain vision of God in His essence.’ E-text, academic.mu.edu/taylorr/Aquinas_and_the_Arabs_Project_Translations/Welcome.html.
    (Book 2, d. 17, q. 2, a. 1, and book 4, d. 49, q. 2, a. 1. These drafts are samples of a partial but extensive translation to be published by Cambridge University Press; the project is described at academic.mu.edu/taylorr/Aquinas_and_the_Arabs/Phase_One__Commentary_on_the_Sentences.html.)
  • Tugwell, Simon, trans. ‘Commentary on the Sentences, Book 4, distinction 15, question 4.’ In his Albert & Thomas: Selected Writings, 363–418. The Classics of Western Spirituality. New York: Paulist Press, 1988.
  • Unidentified translator. ‘Is the human soul of the divine essence?’ ‘Is the human soul constituted of some matter?’ and ‘Is the intellective soul or intellect one in all men?’ E-text, isidore.co/aquinas/english/Sentences2.htm.
    (Book 2, d. 17, q. 1, aa. 1–2 and q. 2, a. 1.)
  • West, Jason Lewis Andrew, trans. Sentences Commentary: In III Sent., d. 5, q. 1, aa. 2–3 and d. 6, q. 2, aa. 1–2. E-text, hosted.desales.edu/w4/philtheo/loughlin/ATP/index.html and isidore.co/aquinas/Sentences.htm.
    (Latin and English of four articles concerning the hypostatic union.)

Summa contra gentiles

Summa theologiae

Besides the countless partial editions, especially of the treatise on God, the treatise on man, and the treatise on law, see the following complete translations:

Commentaries on Scripture

Besides the snippets edited by C.J. Callan in Sermon Matter from St. Thomas Aquinas on the Epistles and Gospels of the Sundays and Feast Days (Advent to Easter) (St. Louis: B. Herder, 1950), see the following:

Catena aurea

Commendatio Sacrae Scripturae

  • McInerny, Ralph, trans. ‘The Inaugural Sermons.’ In Thomas Aquinas, Selected Writings, edited and translated with an introduction and notes by Ralph McInerny, 5–17. Harmondsworth: Penguin, 1998.
    (The first inaugural lecture, based on Ps 103.13, and the second, complementary lecture, based on Baruch 4.1.)
  • Gilhooly, John R., Sr. Albert Marie Surmanski, and Sr. Maria Veritas Marks, trans. Commentary on Psalms; Rigans montes; Hic est liber. Steubenville, Ohio: Emmaus Academic, 2022. Bilingual e-texts from the Aquinas Institute, Psalms, Rigans montes (based on Ps 103.13), and Hic est liber (based on Baruch 4.1).
  • Tugwell, Simon, trans. ‘Inaugural Lecture (1256).’ In his Albert & Thomas: Selected Writings, 355–60. The Classics of Western Spirituality. New York: Paulist Press, 1988.
    (The first inaugural lecture, based on Ps 103.13.)

Expositio et lectura super Epistolas Pauli Apostoli

  • Baer, Chrysostom, trans. Commentary on the Epistle to the Hebrews. South Bend, Ind.: St. Augustine’s Press, 2006.
  • Baer, Chrysostom, trans. Commentary on St. Paul’s Epistles to Timothy, Titus, and Philemon. South Bend, Ind.: St. Augustine’s Press, 2006.
  • Boguslawaski, Steven C., trans. Aquinas’s Commentary on Romans. In preparation.
  • Lamb, Matthew L., trans. Commentary on St. Paul’s Epistle to the Ephesians. Aquinas Scripture Commentaries, 2. Albany: Magi Books, 1966. E-text, isidore.co/aquinas/english/SSEph.htm and isidore.co/aquinas/SSEph.htm (with Thomas’ Latin and Paul’s Greek). Also published with Fr. Larcher’s translation of the commentary on Galatians in Commentary on the Letters of Saint Paul to the Galatians and Ephesians, ed. John Mortensen and Enrique Alarcón, with parallel Latin and the Greek text of the epistle (Lander, Wyo.: The Aquinas Institute, 2012). E-text from the Aquinas Institute, aquinas.cc.
    (Also on CD-ROM from InteLex.)
  • Larcher, Fabian R., trans. Commentary on the Letter of Saint Paul to the Romans, ed. John Mortensen and Enrique Alarcón, with parallel Latin and the Greek text of the epistle. Lander, Wyo.: The Aquinas Institute, 2012. E-text, aquinas.cc.
  • Larcher, Fabian R., trans. Commentary on the Letters of Saint Paul to the Philippians, Colossians, Thessalonians, Timothy, Titus, and Philemon, ed. John Mortensen and Enrique Alarcón, with parallel Latin and the Greek text of the epistles. Lander, Wyo.: The Aquinas Institute, 2012. E-text, aquinas.cc.
  • Larcher, Fabian R., trans. Commentary by Saint Thomas Aquinas on the Epistle to the Colossians. E-text, isidore.co/aquinas/english/SSColossians.htm and isidore.co/aquinas/SSColossians.htm (multilingual).
  • Larcher, Fabian R., and Daniel Keating, trans. Commentary by Saint Thomas Aquinas on the First Epistle to the Corinthians. E-text, isidore.co/aquinas/english/SS1Cor.htm, isidore.co/aquinas/SS1Cor.htm (multilingual), isidore.co/aquinas/english/SS2Cor.htm, and isidore.co/aquinas/SS2Cor.htm (multilingual). Also published, together with the commentary on the second epistle, in Fabian Larcher, Beth Mortensen, and Daniel Keating, trans., Commentary on the Letters of Saint Paul to the Corinthians, ed. John Mortensen and Enrique Alarcón, with parallel Latin, the Greek text of the epistles, and the chapters by Peter of Tarentaise (Lander, Wyo.: The Aquinas Institute, 2012). E-text from the Aquinas Institute, aquinas.cc.
  • Larcher, Fabian R., trans. Commentary by Saint Thomas Aquinas on the Second Epistle to the Corinthians. E-text from the Aquinas Institute, aquinas.cc.
  • Larcher, Fabian R., trans. Commentary on St. Paul’s Epistle to the Galatians. Aquinas Scripture Commentaries, 1. Albany: Magi Books, 1966. Also published with Fr. Lamb’s translation of the commentary on Ephesians in Commentary on the Letters of Saint Paul to the Galatians and Ephesians, ed. John Mortensen and Enrique Alarcón, with parallel Latin and the Greek text of the epistle (Lander, Wyo.: The Aquinas Institute, 2012). E-text from the Aquinas Institute, aquinas.cc.
    (Also on CD-ROM from InteLex.)
  • Larcher, Fabian R., trans. Commentary by Saint Thomas Aquinas on the Epistle to the Hebrews. E-text, isidore.co/aquinas/english/SSHebrews.htm and isidore.co/aquinas/SSHebrews.htm (multilingual). Also edited by John Mortensen and Enrique Alarcón under the title Commentary on the Letter of Saint Paul to the Hebrews, with parallel Latin and the Greek text of the epistle (Lander, Wyo.: The Aquinas Institute, 2012). E-text from the Aquinas Institute, aquinas.cc.
  • Larcher, Fabian R., and Michael Duffy, trans. Commentary on St. Paul’s First Letter to the Thessalonians and the Letter to the Philippians. Aquinas Scripture Series, 3. Albany: Magi Books, 1969.
    (Also on CD-ROM from InteLex.)
  • McInerny, Ralph, trans. Exposition of Paul’s Epistle to Philemon. In Thomas Aquinas, Selected Writings, edited and translated with an introduction and notes by Ralph McInerny, 812–21. Harmondsworth: Penguin, 1998.
  • Rogers, Eugene F., Jr., trans. ‘Selections from Thomas Aquinas’s Commentary on Romans.’ In The Theological Interpretation of Scripture: Classic and Contemporary Readings, ed. Stephen E. Fowl, 325–35. Blackwell Readings in Modern Theology. Oxford: Blackwell Publishers, 1997.
    (Parts of the commentary on Rom 9–11.)
  • Rzeczkowski, Matthew, trans. Commentary on Paul’s First Epistle to the Corinthians. In Thomas Aquinas, The Gifts of the Spirit: Selected Spiritual Writings, ed. Benedict M. Ashley, 21–78. Hyde Park, N.Y.: New City Press, 1995.
    (On 1 Cor 12–13.)
  • Sirilla, Michael, trans. Commentary on Paul’s First and Second Epistles to Timothy and His Epistle to Titus.
    (In progress.)
  • Tugwell, Simon, trans. ‘From the First Lectures on St. Paul’ and ‘From the Commentary on Romans.’ In his Albert & Thomas: Selected Writings, 433–38. The Classics of Western Spirituality. New York: Paulist Press, 1988.
    (On 1 Cor 14.13–15, 1 Tim 2.1, and Rom 8.26–27.)

Expositio in Job ‘ad litteram’

  • Mullady, Brian, trans. Commentary on Job, edited by the Aquinas Institute, with Thomas’ Latin text and the Vulgate and Septuagint translations of Job (Lander, Wyo.: The Aquinas Institute, 2016). E-text from the Aquinas Institute, aquinas.cc.
  • Yaffe, Martin D., and Anthony Damico, trans. The Literal Exposition on Job: A Scriptural Commentary Concerning Providence. Classics in Religious Studies, 7. Atlanta, Ga.: Scholars Press, 1989.
    (Also on CD-ROM from InteLex.)

Expositio super Isaiam ad litteram

Logos Bible Software has proposed a complete translation, with facing Latin, in electronic form; pre-orders, by which the company is measuring interest in the project and determining whether to proceed, are being accepted. The following are available:

  • Martin, Ben, Mark Foudy, and Louis St. Hilaire, trans. Commentary on Isaiah. Steubenville, Ohio: Emmaus Academic, forthcoming. Bilingual e-text from the Aquinas Institute, aquinas.cc.
    (See also Thomas’ division of the text.)
  • Rzeczkowski, Matthew, trans. Commentary on the Book of the Prophet Isaiah. In Thomas Aquinas, The Gifts of the Spirit: Selected Spiritual Writings, ed. Benedict M. Ashley, 87–91. Hyde Park, N.Y.: New City Press, 1995.
    (Selection on Is 11.2.)

Lectura super Johannem

  • Weisheipl, James A., and Fabian R. Larcher, trans. Commentary on the Gospel of John. Aquinas Scripture Series, 4. Albany: Magi Books, 1980.
    (Part 1 only. Also on CD-ROM from InteLex.)
  • Larcher, Fabian R., trans. Commentary on the Gospel of John. Albany: Magi Books, 1998.
    (Part 2.)
  • Weisheipl, James A., and Fabian R. Larcher, trans., with introduction and notes by Daniel Keating and Matthew Levering. Commentary on the Gospel of John. 3 vols. Thomas Aquinas in Translation. Washington, D.C.: The Catholic University of America Press, 2010. Also edited by the Aquinas Institute in 2 volumes, with parallel Latin text and the Greek text of the gospel (Lander, Wyo.: The Aquinas Institute, 2013. E-text from the Aquinas Institute, aquinas.cc.

Lectura super Matthaeum

  • Holmes, Jeremy, and Beth Mortensen, trans. Commentary on the Gospel of Matthew, edited by the Aquinas Institute in 2 volumes. Lander, Wyo.: The Aquinas Institute, 2013. E-text, aquinas.cc.
    (Based on the work of the Leonine Commission; includes parallel Latin and the Greek text of the gospel, as well as the missing texts of Mt 5:11–6:8 and 6:14–19.)
  • Kimball, Paul, trans. Commentary on the Gospel of St. Matthew. Dolorosa Press, 2012.
    (Includes the text to replace the lacuna in chapters 5 and 6 using the Basel manuscript of Peter d’Andria.)
  • Tugwell, Simon, trans. ‘From the Lectures on St. Matthew.’ In his Albert & Thomas: Selected Writings, 445–75. The Classics of Western Spirituality. New York: Paulist Press, 1988.
    (On Mt 6.5–15.)

Postilla super Psalmos

  • McDonald, Hugh, Stephen Loughlin, et al., trans. St. Thomas’s Commentary on the Psalms. E-text, hosted.desales.edu/w4/philtheo/loughlin/ATP/index.html.
    (In progress; Latin and English.)
  • Rzeczkowski, Matthew, trans. Commentary on the Psalms of David. In Thomas Aquinas, The Gifts of the Spirit: Selected Spiritual Writings, ed. Benedict M. Ashley, 95–133. Hyde Park, N.Y.: New City Press, 1995.
    (Prologue, and commentary on Ps 45.)
  • Surmanski, Sr. Albert Marie, Sr. Maria Veritas Marks, and John R. Gilhooly, trans. Commentary on Psalms; Rigans montes; Hic est liber. Steubenville, Ohio: Emmaus Academic, 2022. Bilingual e-texts from the Aquinas Institute, Psalms, Rigans montes, and Hic est liber.

Postilla super Threnos

  • Martin, Ben, Mark Foudy, and Louis St. Hilaire, trans. Commentary on the Lamentations of Jeremiah. Lander, Wyo.: The Aquinas Institute, forthcoming. Bilingual e-text from the Aquinas Institute, aquinas.cc.
  • Reilly, F.F., trans., with some revision by Joseph Kenny. Thomas Aquinas: Commentary on Lamentations. E-text, isidore.co/aquinas/SSLamentations.htm.
    (Does not include the proem.)

Super Ieremiam

Logos Bible Software has proposed a complete translation, with facing Latin, in electronic form; pre-orders, by which the company is measuring interest in the project and determining whether to proceed, are being accepted. The following is available:

  • Martin, Ben, Mark Foudy, and Louis St. Hilaire, trans. Commentary on the Prophet Jeremiah. Lander, Wyo.: The Aquinas Institute, forthcoming. Bilingual e-text from the Aquinas Institute, aquinas.cc.

Commentaries on Aristotle

Sententia de caelo et mundo

  • Larcher, Fabian R., and Pierre H. Conway, trans. Exposition of Aristotle’s Treatise On the Heavens. 2 vols. Columbus, Ohio: College of St. Mary of the Springs, 1964. E-text, isidore.co/aquinas/english/DeCoelo.htm and isidore.co/aquinas/DeCoelo.htm (bilingual).
    (Also on CD-ROM from InteLex.)
  • McInerny, Ralph, trans. ‘The Range of Natural Philosophy: Preface to the Commentary on On the Heavens.’ In Thomas Aquinas, Selected Writings, edited and translated with an introduction and notes by Ralph McInerny, 444–47. Harmondsworth: Penguin, 1998.

Sententia de memoria et reminiscentia

  • Burchill, John, trans. On Memory and Recollection. Dover, Mass.: Dominican House of Philosophy, 1963. E-text of lessons 1–7, isidore.co/aquinas/english/MemoriaReminiscentia.htm and isidore.co/aquinas/MemoriaReminiscentia.htm (bilingual).
    (Also on CD-ROM from InteLex.)
  • Macierowski, Edward M., trans. In Commentaries on Aristotle’s ‘On Sense and What Is Sensed’ and ‘On Memory and Recollection.’ Thomas Aquinas in Translation. Washington, D.C.: The Catholic University of America Press, 2005.
  • McDermott, Timothy, trans. Commentary on Aristotle’s De Memoria et Reminiscentia, 449 b 30–450 a 25. In Thomas Aquinas, Selected Philosophical Writings, selected and translated by Timothy McDermott, 138–44. World’s Classics. Oxford: Oxford University Press, 1993.
  • Pasnau, Robert C., trans. Commentary on Aristotle’s De memoria et reminiscentia. E-text, spot.colorado.edu/~pasnau/research/indmr.htm.
    (The translator describes this as ‘a rough translation of chapters two and three, based on the Leonine edition.’)

Sententia de sensu et sensato

  • McInerny, Ralph, trans. ‘The Range of Natural Philosophy: Preface to the Commentary on On Sense and the Sensed Object.’ In Thomas Aquinas, Selected Writings, edited and translated with an introduction and notes by Ralph McInerny, 447–54. Harmondsworth: Penguin, 1998.
  • White, Kevin, trans. In Commentaries on Aristotle’s ‘On Sense and What Is Sensed’ and ‘On Memory and Recollection.’ Thomas Aquinas in Translation. Washington, D.C.: The Catholic University of America Press, 2005.

Sententia libri Ethicorum

  • Conway, Pierre, trans. St. Thomas Aquinas on Aristotle’s Love and Friendship: Ethics, Books VIII–IX. Providence, R.I.: Providence College Press, 1951.
  • Litzinger, C.I., trans. Commentary on the Nicomachean Ethics. 2 vols. Library of Living Catholic Thought. Chicago: Regnery, 1964; reprinted in 1 vol. with revisions as Commentary on Aristotle’s Nicomachean Ethics, Aristotelian Commentary Series, Notre Dame, Ind.: Dumb Ox Books, 1993.
    (1964 edition also on CD-ROM from InteLex; 1993 edition reprinted in 1999 for readers outside the U.S.A. by Thoemmes Press.)

Sententia libri Politicorum

  • Fortin, Ernest L., and Peter D. O’Neill, trans. ‘Thomas Aquinas: Commentary on the Politics.’ In Medieval Political Philosophy: A Sourcebook, ed. Ralph Lerner and Muhsin Mahdi, 298–334. Agora Editions. New York: Free Press of Glencoe, 1963.
    (Proem, 1.1, and 3.1–6. Also on CD-ROM from InteLex.)
  • Fortin, Ernest L., and Stephen Brown, trans. Commentary on the Politics of Aristotle. Thomas Aquinas in Translation. Washington, D.C.: The Catholic University of America Press, in preparation.
  • Regan, Richard J., trans. Commentary on the Politics. Indianapolis: Hackett, 2007.

Sententia super De anima

  • Foster, Kenelm, and Silvester Humphries, trans. Aristotle’s De Anima in the Version of William of Moerbeke and the Commentary of St. Thomas Aquinas. New Haven: Yale University Press, 1951; reprinted with revisions as Commentary on Aristotle’s De Anima, Aristotelian Commentary Series, Notre Dame, Ind.: Dumb Ox Books, 1994.
    (1951 edition also on CD-ROM from InteLex; 1994 edition reprinted in 1999 for readers outside the U.S.A. by Thoemmes Press.)
  • Pasnau, Robert C., trans. Commentary on Aristotle’s De anima. New Haven: Yale University Press, 1999.

Sententia super libros De generatione et corruptione

Sententia super Metaphysicam

  • Rowan, John P., trans. Commentary on the Metaphysics of Aristotle. 2 vols. Chicago: Regnery, 1964; reprinted in 1 vol. with revisions as Commentary on Aristotle’s Metaphysics, Aristotelian Commentary Series, Notre Dame, Ind.: Dumb Ox Books, 1995.
    (The earlier edition is also at www.logicmuseum.com/wiki/Authors/Thomas_Aquinas/metaphysics and on CD-ROM from InteLex; the 1995 edition was reprinted in 1999 for readers outside the U.S.A. by Thoemmes Press.)

Sententia super Meteora

Sententia super Peri hermenias

  • Martin, Christopher, trans. In his The Philosophy of Thomas Aquinas: Introductory Readings, 18–48. London: Routledge, 1988.
    (Book 1, lessons 4, 5, and 13–15.)
  • McDermott, Timothy, trans. Commentary on Aristotle’s De Interpretatione, 1.9 (18 b 26–19 a 22). In Thomas Aquinas, Selected Philosophical Writings, selected and translated by Timothy McDermott, 277–84. World’s Classics. Oxford: Oxford University Press, 1993.
    (Book 1, lesson 14, on providence, chance, and freedom.)
  • McInerny, Ralph, trans. ‘How Words Mean: Exposition of On Interpretation, 1–5.’ In Thomas Aquinas, Selected Writings, edited and translated with an introduction and notes by Ralph McInerny, 456–81. Harmondsworth: Penguin, 1998.
    (Includes the preface as well as the first five lessons.)
  • Oesterle, Jean, trans. Aristotle on Interpretation: Commentary by St. Thomas and Cajetan. Mediaeval Philosophical Texts in Translation, 11. Milwaukee: Marquette University Press, 1962. Reprinted, with a new introduction, as Commentary on Aristotle’s On Interpretation, Notre Dame, Ind.: Dumb Ox Books, 2004.
    (Also on CD-ROM from InteLex; 1962 edition, without notes but with Thomas’ Latin, at www.logicmuseum.com/wiki/Authors/Thomas_Aquinas/perihermenias.)

Sententia super Physicam

Sententia super Posteriora Analytica

  • Berquist, Richard, trans. Commentary on Aristotle’s Posterior Analytics. South Bend, Ind.: St. Augustine’s Press, 2007.
  • Conway, Pierre, trans., revised by William H. Kane. Exposition of the Posterior Analytics of Aristotle. Quebec: La Librairie Philosophique M. Doyon, 1956.
    (Mimeograph.)
  • Conway, Pierre, and Jean Oesterle, trans. Commentary on Aristotle’s Posterior Analytics. Aristotelian Commentary Series. Notre Dame, Ind.: Dumb Ox Books, forthcoming.
  • Larcher, F.R., trans. Commentary on the Posterior Analytics of Aristotle. Albany: Magi Books, 1970. E-text with Thomas’ Latin at www.logicmuseum.com/authors/aquinas/posterioranalytics/aquinasPA.htm.
    (Also on CD-ROM from InteLex.)

Commentaries on Neoplatonic texts

Expositio in librum Boethii De hebdomadibus

  • King, Peter, trans. Aquinas: Exposition of Boethius’s ‘Hebdomads.’ E-text, individual.utoronto.ca/pking/AQUINAS.Exposition_of_Hebdomads.pdf.
  • McInerny, Ralph, trans. ‘How are Things Good? Exposition of On the Hebdomads of Boethius.’ In Thomas Aquinas, Selected Writings, edited and translated with an introduction and notes by Ralph McInerny, 143–62. Harmondsworth: Penguin, 1998.
  • O’Reilly, Peter, trans. In his ‘Sancti Thomae de Aquino Expositio super librum Boetii “De Hebdomadibus”: An Edition and a Study.’ Ph.D. diss., University of Toronto, 1960.
  • Schultz, Janice L., and Edward A. Synan, trans. An Exposition of the ‘On the Hebdomads’ of Boethius. Thomas Aquinas in Translation. Washington, D.C.: The Catholic University of America Press, 2001.
    (Includes facing Latin text.)
  • Tugwell, Simon, trans. ‘Prologue to the Commentary on Boethius’ De Hebdomadibus.’ In his Albert & Thomas: Selected Writings, 527–28. The Classics of Western Spirituality. New York: Paulist Press, 1988.

Expositio super Dionysium De divinis nominibus

  • Marsh, Harry C., trans. ‘A Translation of Thomas Aquinas’ In Librum beati Dionysii de divinis nominibus expositio.’ In his ‘Cosmic Structure and the Knowledge of God: Thomas Aquinas’ In Librum beati Dionysii de divinis nominibus expositio,’ 265–549. Ph.D. diss., Vanderbilt University, 1994.
    (Available from ProQuest as item 9431626.)
  • Jarka-Sellers, Hannes, trans. On the Divine Names. Thomas Aquinas in Translation. Washington, D.C.: The Catholic University of America Press, in preparation.
    (Until this appears, non-Latinists may find some of its remarks on beauty translated in Ananda Kentish Coomaraswamy, Coomaraswamy, vol. 1, Selected Papers: Traditional Art and Symbolism, ed. Roger Lipsey, Bollingen, 89 [Princeton: Princeton University Press, 1977]. See also Umberto Eco, The Aesthetics of Thomas Aquinas, translated by Hugh Bredin [Cambridge, Mass.: Harvard University Press, 1988]. Thomas’ prologue appears in Thomas Aquinas, Selected Writings, edited and translated with an introduction and notes by Ralph McInerny, 430–31 [Harmondsworth: Penguin, 1998].)

Expositio super librum Boethii De trinitate

  • Brennan, Rose E., trans. The Trinity and the Unicity of the Intellect. St. Louis: B. Herder, 1946. E-text of questions 1–4 with parallel Latin, www.logicmuseum.com/authors/aquinas/superboethium-index.htm.
  • Cogan, Marc, trans. Commentary on Boethius’ On the Trinity, q. 5, a. 1. E-text, hosted.desales.edu/w4/philtheo/loughlin/ATP/Boethius/Q5A1.html.
  • Maurer, Armand, trans. Faith, Reason and Theology: Questions I–IV of his Commentary on the De Trinitate of Boethius. Mediaeval Sources in Translation, 32. Toronto: Pontifical Institute of Mediaeval Studies, 1987.
    (Also on CD-ROM from InteLex.)
  • Maurer, Armand, trans. The Division and Methods of the Sciences: Questions V and VI of his Commentary on the De Trinitate of Boethius. 4th rev. ed. Mediaeval Sources in Translation, 3. Toronto: Pontifical Institute of Mediaeval Studies, 1986. E-text with parallel Latin, www.logicmuseum.com/authors/aquinas/superboethium-index.htm.
    (Also on CD-ROM from InteLex.)
  • McInerny, Ralph, trans. ‘Theology, Faith and Reason: On Boethius On the Trinity, 1–2.’ In Thomas Aquinas, Selected Writings, edited and translated with an introduction and notes by Ralph McInerny, 110–41. Harmondsworth: Penguin, 1998.
  • White, Victor, trans. On Searching into God: Being an Exposition of the ‘De Trinitate’ of Boethius. Question 2: On the Making Manifest of the Divine Knowledge. Oxford: Oxonian Press, 1947; reprinted from Blackfriars, November 1943 (Supplement).

Expositio super librum De causis

  • Guagliardo, Vincent A., Charles R. Hess, and Richard C. Taylor, trans. Commentary on the Book of Causes. Thomas Aquinas in Translation. Washington, D.C.: The Catholic University of America Press, 1996.
  • McInerny, Ralph, trans. The Exposition of The Book of Causes, 1–5. In Thomas Aquinas, Selected Writings, edited and translated with an introduction and notes by Ralph McInerny, 787–810. Harmondsworth: Penguin, 1998.
    (Includes the prologue as well as the first five lessons.)

Disputations

De anima

  • Robb, James H., trans. Questions on the Soul. Mediaeval Philosophical Texts in Translation, 27. Milwaukee: Marquette University Press, 1984.
    (Also on CD-ROM from InteLex.)
  • Rowan, J.P., trans. The Soul. St. Louis: B. Herder, 1949.

De caritate

  • Atkins, E. M., trans. Thomas Aquinas: Disputed Questions on the Virtues, ed. E. M. Atkins and Thomas Williams. Cambridge: Cambridge University Press, 2005.
    (Also includes the disputations On the Virtues in General, On Fraternal Correction, On Hope, and On the Cardinal Virtues.)
  • Hause, Jeffrey and Claudia Eisen Murphy, trans. Disputed Questions on Virtue, with an introduction and commentary by Jeffrey Hause. Indianapolis: Hackett, 2010.
    (Also includes the disputations On the Virtues in General, On Fraternal Correction, On Hope, and On the Cardinal Virtues.)
  • Kendzierski, Lottie H., trans. On Charity (De caritate). Mediaeval Philosophical Texts in Translation, 10. Milwaukee: Marquette University Press, 1960.
    (Also on CD-ROM from InteLex.)

De correctione fraterna

  • Atkins, E. M., trans. Thomas Aquinas: Disputed Questions on the Virtues, ed. E. M. Atkins and Thomas Williams. Cambridge: Cambridge University Press, 2005.
    (Also includes the disputations On the Virtues in General, On Charity, On Hope, and On the Cardinal Virtues.)
  • Hause, Jeffrey and Claudia Eisen Murphy, trans. Disputed Questions on Virtue, with an introduction and commentary by Jeffrey Hause. Indianapolis: Hackett, 2010.
    (Also includes the disputations On the Virtues in General, On Charity, On Hope, and On the Cardinal Virtues.)

De malo

  • McInerny, Ralph, trans. ‘On Human Choice: Disputed Question on Evil, 6.’ In Thomas Aquinas, Selected Writings, edited and translated with an introduction and notes by Ralph McInerny, 552–64. Harmondsworth: Penguin, 1998.
  • Oesterle, John A. and Jean T., trans. On Evil. Notre Dame, Ind.: University of Notre Dame Press, 1995.
    (Also on CD-ROM from InteLex.)
  • Regan, Richard, trans. The ‘De malo’ of Thomas Aquinas. Oxford: Oxford University Press, 2002.
    (Includes facing Latin text.)
  • Regan, Richard, trans. On Evil. Edited with an introduction and notes by Brian Davies. Oxford: Oxford University Press, 2003.
    (English only.)

De potentia

  • Freddoso, Alfred J., trans. De Potentia Dei 3.1 and 3.4. E-text, www3.nd.edu/~afreddos/translat/aquinas1.htm.
    (Incomplete translation of two articles on creation.)
  • McInerny, Ralph, trans. ‘On the Divine Simplicity: Disputed Question of the Power of God, 7.’ In Thomas Aquinas, Selected Writings, edited and translated with an introduction and notes by Ralph McInerny, 291–342. Harmondsworth: Penguin, 1998.
  • Regan, Richard, trans. The Power of God. Oxford: Oxford University Press, 2012.
    (N.B.: This version includes only those objections considered most significant by the translator; it also rearranges the text so that Thomas’ reply comes before the objections, and the reply to each objection comes right after the objection.)
  • Selner-Wright, Susan C., trans. On Creation [Quaestiones Disputatae de Potentia Dei, Q. 3]. Thomas Aquinas in Translation. Washington, D.C.: The Catholic University of America Press, 2010.
  • Shapcote, Laurence, trans. On the Power of God. 3 vols. London: Burns, Oates & Washbourne, 1932–34; reprinted in 1 vol., Westminster, Md.: Newman, 1952; reprint, Wipf and Stock, 2004. Bilingual e-text, www.logicmuseum.com/wiki/Authors/Thomas_Aquinas/depotentia.
    (Also on CD-ROM from InteLex. There is some inconsistency in the spelling of the translator’s name, and catalogs may have ‘Lawrence.’)

De spe

  • Atkins, E. M., trans. Thomas Aquinas: Disputed Questions on the Virtues, ed. E. M. Atkins and Thomas Williams. Cambridge: Cambridge University Press, 2005.
    (Also includes the disputations On the Virtues in General, On Charity, On Fraternal Correction, and On the Cardinal Virtues.)
  • Hause, Jeffrey and Claudia Eisen Murphy, trans. Disputed Questions on Virtue, with an introduction and commentary by Jeffrey Hause. Indianapolis: Hackett, 2010.
    (Also includes the disputations On the Virtues in General, On Charity, On Fraternal Correction, and On the Cardinal Virtues.)

De spiritualibus creaturis

  • Fitzpatrick, Mary C., and John J. Wellmuth, trans. On Spiritual Creatures. Mediaeval Philosophical Texts in Translation, 5. Milwaukee: Marquette University Press, 1949.
    (Also on CD-ROM from InteLex.)
  • Goodwin, Colin Robert, trans. A Translation of the Quaestio disputata de spiritualibus creaturis of St Thomas Aquinas, with Accompanying Notes. M.A. thesis, Australian Catholic University, 2002. E-text, researchbank.acu.edu.au/theses/45/.

De unione verbi incarnati

  • Nutt, Roger W., trans. Thomas Aquinas, «De unione Verbi incarnati». Dallas Medieval Texts and Translations, 21. Leuven: Peeters, 2015.
    (Includes an introduction and the Latin text.)
  • West, Jason Lewis Andrew, trans. A Disputed Question: Concerning the Union of the Word Incarnate. E-text, hosted.desales.edu/w4/philtheo/loughlin/ATP/index.html.
    (With facing Latin text. In progress: the first four of the five articles are complete.)

De veritate

  • Freddoso, Alfred J., trans. On Faith: Quaestiones disputatae de veritate 14.1–2. E-text, www3.nd.edu/~afreddos/translat/aquinas3.htm and www3.nd.edu/~afreddos/translat/aquinas5.htm.
  • Froelich, Gregory, trans. On the Teacher. E-text, hosted.desales.edu/w4/philtheo/loughlin/ATP/De_Magistro/De_Magistro_11_1.html.
    (Latin and English. This is a partial translation of De veritate, q. 11 a. 1; the corpus is complete, but for the rest, only objections and replies 1–5 and 11–12 and the fifth sed contra are present.)
  • Goodwin, Robert P., trans. On Free Choice. In his Selected Writings of St. Thomas Aquinas: The Principles of Nature, On Being and Essence, On the Virtues in General, On Free Choice. The Library of Liberal Arts. Indianapolis: Bobbs–Merrill, 1965.
    (This is q. 24 of De veritate, but note that Goodwin omits the objections and their replies.)
  • McInerny, Ralph, trans. ‘The Meanings of Truth: Disputed Question on Truth, 1,’ ‘On the Teacher: Disputed Question on Truth, 11,’ and ‘On Conscience: Disputed Question on Truth, 17.’ In Thomas Aquinas, Selected Writings, edited and translated with an introduction and notes by Ralph McInerny, 164–238. Harmondsworth: Penguin, 1998.
  • Mulligan, Robert W., James V. McGlynn, and Robert W. Schmidt, trans. Truth. 3 vols. Library of Living Catholic Thought. Chicago: Regnery, 1952–54; reprint, Indianapolis: Hackett, 1994.
    (Also on CD-ROM from InteLex.)

De virtutibus cardinalibus

  • Atkins, E. M., trans. Thomas Aquinas: Disputed Questions on the Virtues, ed. E. M. Atkins and Thomas Williams. Cambridge: Cambridge University Press, 2005.
    (Also includes the disputations On the Virtues in General, On Charity, On Fraternal Correction, and On Hope.)
  • Hause, Jeffrey and Claudia Eisen Murphy, trans. Disputed Questions on Virtue, with an introduction and commentary by Jeffrey Hause. Indianapolis: Hackett, 2010.
    (Also includes the disputations On the Virtues in General, On Charity, On Fraternal Correction, and On Hope.)
  • Houser, R.E., trans. The Cardinal Virtues: Aquinas, Albert, and Philip the Chancellor. Mediaeval Sources of Translation, 39. Toronto: Pontifical Institute of Mediaeval Studies, 2004.
  • McInerny, Ralph, trans. Disputed Questions on Virtue: Quaestio disputata de virtutibus in communi; Quaestio disputata de virtutibus cardinalibus. South Bend, Ind.: St. Augustine’s Press, 1998.

De virtutibus in communi

  • Atkins, E. M., trans. Thomas Aquinas: Disputed Questions on the Virtues, ed. E. M. Atkins and Thomas Williams. Cambridge: Cambridge University Press, 2005.
    (Also includes the disputations On Charity, On Fraternal Correction, On Hope, and On the Cardinal Virtues.)
  • Goodwin, Robert P., trans. On the Virtues in General. In his Selected Writings of St. Thomas Aquinas: The Principles of Nature, On Being and Essence, On the Virtues in General, On Free Choice, 75–113. The Library of Liberal Arts. Indianapolis: Bobbs–Merrill, 1965.
    (N.B.: Goodwin omits the objections and their replies.)
  • Hause, Jeffrey and Claudia Eisen Murphy, trans. Disputed Questions on Virtue, with an introduction and commentary by Jeffrey Hause. Indianapolis: Hackett, 2010.
    (Also includes the disputations On Charity, On Fraternal Correction, On Hope, and On the Cardinal Virtues.)
  • McInerny, Ralph, trans. Disputed Questions on Virtue: Quaestio disputata de virtutibus in communi; Quaestio disputata de virtutibus cardinalibus. South Bend, Ind.: St. Augustine’s Press, 1998.
  • Reid, John Patrick, trans. On the Virtues (in General). Providence, R.I.: Providence College Press, 1951.
    (Also on CD-ROM from InteLex.)

Quaestiones de quodlibet I–XII

Utrum anima coniuncta cognoscat seipsam per essentiam

  • Lambert, Richard T., trans. Disputed Question on the Soul’s Knowledge of Itself. 1987. Typescript.
    (To order, visit the Translation Clearing House. Also reproduced as an appendix in the translator’s monograph, Self Knowledge in Thomas Aquinas: The Angelic Doctor on the Soul’s Knowledge of Itself, 287–96 [Bloomington, Ind.: AuthorHouse, 2007].)

Polemical writings

Contra doctrinam retrahentium a religione

Contra impugnantes Dei cultum et religionem

De aeternitate mundi contra murmurantes

  • Clark, Mary T., trans. On the Eternity of the World against the Grumblers. In her An Aquinas Reader, 178–85. Garden City, N.Y.: Image Books, 1972.
  • McInerny, Ralph, trans. On the Eternity of the World against Murmurers. In his A First Glance at St. Thomas Aquinas: A Handbook for Peeping Thomists, 49–56. Notre Dame, Ind.: University of Notre Dame Press, 1990. A very similar translation appears in Thomas Aquinas, Selected Writings, edited and translated with an introduction and notes by Ralph McInerny, 711–17. Harmondsworth: Penguin, 1998.
  • Miller, Robert T., trans. On the Eternity of the World. E-text, sourcebooks.fordham.edu/basis/aquinas-eternity.asp and www.logicmuseum.com/time/aquinaseternitate.htm (bilingual).
  • Vollert, Cyril, trans. On the Eternity of the World (De aeternitate mundi). In St. Thomas, Siger de Brabant, and St. Bonaventure, On the Eternity of the World, trans. Cyril Vollert, Lottie Kenzierski, and Paul M. Byrne, 19–25. Mediaeval Philosophical Texts in Translation, 16. Milwaukee: Marquette University Press, 1964.
    (Also on CD-ROM from InteLex.)

De perfectione spiritualis vitae

  • Procter, John, trans. The Religious State, The Episcopate and the Priestly Office: A Translation of the Minor Work of the Saint on the Perfection of the Spiritual Life. St. Louis: B. Herder, 1902, and London: Sands, 1903; reprint, Westminster, Md.: Newman, 1950.
    (Library catalogs often have ‘J. Proctor,’ apparently through confusion with an earlier writer. Also on CD-ROM from InteLex.)

De unitate intellectus contra Averroistas

  • Brennan, Rose E., trans. The Trinity and the Unicity of the Intellect. St. Louis: B. Herder, 1946.
  • McInerny, Ralph M. Aquinas against the Averroists: On There Being Only One Intellect. Purdue University Series in the History of Philosophy. West Lafayette, Ind.: Purdue University Press, 1993.
    (Latin and English. Also on CD-ROM from InteLex.)
  • Zedler, Beatrice H., trans. On the Unity of the Intellect against the Averroists (De Unitate Intellectus Contra Averroistas). Mediaeval Philosophical Texts in Translation, 19. Milwaukee: Marquette University Press, 1968.
    (Also on CD-ROM from InteLex.)

Other authentic works

Collationes de decem praeceptis

  • Collins, Joseph B., trans. In The Catechetical Instructions of St. Thomas, 69–116. New York: Wagner, 1939; reprint, Ft. Collins, Colo.: Roman Catholic Books, 2000; revised and reprinted in pp. 3–80 of God’s Greatest Gifts: Commentaries on the Commandments and the Sacraments, Manchester, N.H.: Sophia Institute, 1992; paperback ed., Sophia Institute, 1997; reprinted with The Three Greatest Prayers under the title The Aquinas Catechism: A Simple Explanation of the Catholic Faith by the Church’s Greatest Theologian, Sophia Institute, 2000; e-text, www.ewtn.com/catholicism/library/catechetical-instructions-of-st-thomas-12544; e-text with word lists, concordances, and statistics, www.intratext.com/X/ENG0029.htm (www.intratext.com/Aiuto/ENG explains these tools).
    (Also on CD-ROM from InteLex.)
  • Shapcote, Laurence, trans. The Commandments of God: Conferences on the Two Precepts of Charity and the Ten Commandments. London: Burns & Oates, 1937.
    (There is some inconsistency in the spelling of the translator’s name, and catalogs may have ‘Lawrence.’)
  • www.vatican.va/spirit/documents/spirit_20010116_thomas-aquinas_en.html presents most of chapter 2, on charity.

Collationes super Pater Noster

  • Collins, Joseph B., trans. In The Catechetical Instructions of St. Thomas, 135–70. New York: Wagner, 1939; reprint, Ft. Collins, Colo.: Roman Catholic Books, 2000; e-text, www.ewtn.com/catholicism/library/catechetical-instructions-of-st-thomas-12546; e-text with word lists, concordances, and statistics, www.intratext.com/X/ENG0029.htm (www.intratext.com/Aiuto/ENG explains these tools).
    (Also on CD-ROM from InteLex.)
  • Firminger, W.K., trans. The Most Devout Exposition of the Lord’s Prayer of St. Thomas Aq. London: Faith Press, 1927.
  • Shapcote, Laurence, trans. In The Three Greatest Prayers: Commentaries on the Lord’s Prayer, the Hail Mary, and the Apostle’s Creed, 101–60. London: Burns, Oates & Washbourne, 1937; reprint, Westminster, Md.: Newman, 1956; revised and reprinted, Manchester, N.H.: Sophia Institute, 1990, 1997; reprinted with God’s Greatest Gifts under the title The Aquinas Catechism: A Simple Explanation of the Catholic Faith by the Church’s Greatest Theologian, Sophia Institute, 2000.
    (There is some inconsistency in the spelling of the translator’s name, and catalogs may have ‘Lawrence.’)

Collationes super Ave Maria

  • Bugnolo, Alexis, trans. St. Thomas Aquinas on the Angelic Salutation. E-text, franciscan-archive.org/bvm/salut.html.
  • Collins, Joseph B., trans. In The Catechetical Instructions of St. Thomas, 173–80. New York: Wagner, 1939; reprint, Ft. Collins, Colo.: Roman Catholic Books, 2000; e-text, www.ewtn.com/catholicism/library/catechetical-instructions-of-st-thomas-12547; e-text with word lists, concordances, and statistics, www.intratext.com/X/ENG0029.htm (www.intratext.com/Aiuto/ENG explains these tools).
    (Also on CD-ROM from InteLex.)
  • Every, L., trans. ‘Explanation of the Hail Mary.’ Dominicana 39 (1954): 31–38.
  • McInerny, Ralph, trans. Exposition of the Angelic Salutation (Ave Maria). In Thomas Aquinas, Selected Writings, edited and translated with an introduction and notes by Ralph McInerny, 822–27. Harmondsworth: Penguin, 1998.
  • Shapcote, Laurence, trans. In The Three Greatest Prayers: Commentaries on the Lord’s Prayer, the Hail Mary, and the Apostle’s Creed, 163–72. London: Burns, Oates & Washbourne, 1937; reprint, Westminster, Md.: Newman, 1956; revised and reprinted, Manchester, N.H.: Sophia Institute, 1990, 1997; reprinted with God’s Greatest Gifts under the title The Aquinas Catechism: A Simple Explanation of the Catholic Faith by the Church’s Greatest Theologian, Sophia Institute, 2000.
    (There is some inconsistency in the spelling of the translator’s name, and catalogs may have ‘Lawrence.’)

Collationes super Credo in Deum

  • Ayo, Nicholas, trans. The Sermon-Conferences of St. Thomas Aquinas on the Apostles’ Creed. Notre Dame, Ind.: University of Notre Dame Press, 1988; reprint, Wipf and Stock, 2005.
    (Latin and English.)
  • Collins, Joseph B., trans. In The Catechetical Instructions of St. Thomas, 3–66. New York: Wagner, 1939; reprint, Ft. Collins, Colo.: Roman Catholic Books, 2000; e-text, www.ewtn.com/catholicism/library/catechetical-instructions-of-st-thomas-12543; e-text with word lists, concordances, and statistics, www.intratext.com/X/ENG0029.htm (www.intratext.com/Aiuto/ENG explains these tools).
    (Also on CD-ROM from InteLex.)
  • Shapcote, Laurence, trans. In The Three Greatest Prayers: Commentaries on the Lord’s Prayer, the Hail Mary, and the Apostle’s Creed, 3–98. London: Burns, Oates & Washbourne, 1937; reprint, Westminster, Md.: Newman, 1956; revised and reprinted, Manchester, N.H.: Sophia Institute, 1990, 1997; reprinted with God’s Greatest Gifts under the title The Aquinas Catechism: A Simple Explanation of the Catholic Faith by the Church’s Greatest Theologian, Sophia Institute, 2000.
    (There is some inconsistency in the spelling of the translator’s name, and catalogs may have ‘Lawrence.’)

Compendium theologiae

  • Lynch, Lawrence, trans. Compendium of Theology. New York: McMullen, 1947.
  • Regan, Richard, trans. Compendium of Theology. Oxford: Oxford University Press, 2009.
  • Vollert, Cyril, trans. The Compendium of Theology. St. Louis: B. Herder, 1947; reprinted with editorial revisions as Light of Faith: The Compendium of Theology, Manchester, N.H.: Sophia Institute, 1993.
    (Also on CD-ROM from InteLex. Chapters 36–67, on the Trinity, are on-line at www.ewtn.com/catholicism/library/holy-trinity-10173.)

Contra errores Graecorum

  • Fehlner, Peter Damian, trans., in James Likoudis’ Ending the Byzantine Greek Schism: Containing the 14th c. ‘Apologia’ of Demetrios Kydones for Unity with Rome and St. Thomas Aquinas’ ‘Contra Errores Graecorum.’ 2d ed. New Rochelle, N.Y.: Catholics United for the Faith, 1992. E-text, isidore.co/aquinas/english/ContraErrGraecorum.htm and isidore.co/aquinas/ContraErrGraecorum.htm (bilingual).
    (Likoudis’ acknowledgements say, ‘I am grateful to Fr. G.H. Duggan, S.M., of New Zealand, and to Fr. Peter Damian Fehlner, OFM.Conv., for their generous collaboration in translating St. Thomas Aquinas’ Contra Errores Graecorum.’ The e-text is ‘translated by Peter Damian Fehlner, F.I.’ and ‘re-edited and missing chapters supplied by Joseph Kenny, O.P.’ A serious student of the text will want to compare the e-text and the printed translation, since it’s not readily apparent what was missing.)

De articulis fidei et Ecclesiae sacramentis

  • Collins, Joseph B., trans. The Catechetical Instructions of St. Thomas, 119–31. New York: Wagner, 1939; reprint, Ft. Collins, Colo.: Roman Catholic Books, 2000; revised and reprinted in pp. 83–100 of God’s Greatest Gifts: Commentaries on the Commandments and the Sacraments, Manchester, N.H.: Sophia Institute, 1992; paperback ed., Sophia Institute, 1997; reprinted with The Three Greatest Prayers under the title The Aquinas Catechism: A Simple Explanation of the Catholic Faith by the Church’s Greatest Theologian, Sophia Institute, 2000; e-text, www.ewtn.com/catholicism/library/catechetical-instructions-of-st-thomas-12545; e-text with word lists, concordances, and statistics, www.intratext.com/X/ENG0029.htm (www.intratext.com/Aiuto/ENG explains these tools).
    (Part 2 only, on the sacraments. Also on CD-ROM from InteLex.)

De emptione et venditione ad tempus

  • O’Rahilly, Alfred. ‘Notes on St. Thomas III—St. Thomas on Credit.’ Irish Ecclesiastical Record, 5th series, 31 (1928): 159–68; reprinted by Vernon J. Bourke in his The Pocket Aquinas, 223–25, New York: Pocket Books, 1960.
    (O’Rahilly gives both Latin and English with a study; Bourke reprints the English. Also on CD-ROM from InteLex and at isidore.co/aquinas/english/Emptio.htm and isidore.co/aquinas/Emptio.htm [bilingual].)

De ente et essentia

  • Bobik, Joseph. Aquinas on Being and Essence: A Translation and Interpretation. Notre Dame, Ind.: University of Notre Dame Press, 1965.
  • Goodwin, Robert P., trans. On Being and Essence. In his Selected Writings of St. Thomas Aquinas: The Principles of Nature, On Being and Essence, On the Virtues in General, On Free Choice, 33–67. The Library of Liberal Arts. Indianapolis: Bobbs–Merrill, 1965.
  • King, Peter, trans. On Being and Essence. In Aquinas: Basic Works, ed. Jeffrey Hause and Robert Pasnau. Indianapolis: Hackett, 2014.
  • Klima, Gyula, trans. On Being and Essence. E-text, faculty.fordham.edu/klima/Blackwell-proofs/MP_C30.pdf.
  • Leckie, George G., trans. Concerning Being and Essence. Appleton–Century Philosophy Source-books. New York: Appleton–Century–Crofts, 1937.
  • Maurer, Armand, trans. On Being and Essence. 2d rev. ed. Mediaeval Sources in Translation, 1. Toronto: Pontifical Institute of Mediaeval Studies, 1968.
    (Also on CD-ROM from InteLex.)
  • McDermott, Timothy, trans. On Being and Essence. In Thomas Aquinas, Selected Philosophical Writings, selected and translated by Timothy McDermott, 90–113. World’s Classics. Oxford: Oxford University Press, 1993.
  • McInerny, Ralph, trans. On Being and Essence. In Thomas Aquinas, Selected Writings, edited and translated with an introduction and notes by Ralph McInerny, 30–49. Harmondsworth: Penguin, 1998.
  • Miller, Robert T., trans. On Being and Essence. E-text, sourcebooks.fordham.edu/basis/aquinas-esse.asp, www.logicmuseum.com/wiki/Authors/Thomas_Aquinas/esse_essentia (bilingual), and (with parallel Latin and Russian) antology.rchgi.spb.ru/Thomas_Aquinas/De_ente_et_essentia.html.
  • Reidl, C.C., trans. On Being and Essence. Toronto: St. Michael’s College, 1934.

De mixtione elementorum

  • Bobik, Joseph. Aquinas on Matter and Form and the Elements: A Translation and Interpretation of the ‘De Principiis Naturae’ and the ‘De Mixtione Elementorum’ of St. Thomas Aquinas. Notre Dame, Ind.: University of Notre Dame Press, 1998.
    (Includes the Latin.)
  • Larkin, Vincent R., trans. ‘Saint Thomas Aquinas: On the Combining of the Elements.’ Isis 51 (1960): 67–72.
  • McDermott, Timothy, trans. On Compounds of Elements. In Thomas Aquinas, Selected Philosophical Writings, selected and translated by Timothy McDermott, 117–21. World’s Classics. Oxford: Oxford University Press, 1993.
  • Orlowski, Peter, trans. On the Blend of the Elements. Bilingual e-text, isidore.co/aquinas/MixtioElementorum.htm.
  • Spade, Paul Vincent, trans. On the Mixture of the Elements, to Master Philip. Revised draft. 1983. Typescript.
    (Based on the Marietti edition. To order, visit the Translation Clearing House. A 1997 version, based on the Leonine text, may be downloaded at pvspade.com/Logic/docs/mixture.pdf.)

De motu cordis

  • Froelich, Gregory, trans. On the Motion of the Heart. E-Text, hosted.desales.edu/w4/philtheo/loughlin/ATP/index.html.
    (With facing Latin text.)
  • Larkin, Vincent R., trans. ‘Saint Thomas Aquinas on the Movement of the Heart.’ Journal of the History of Medicine 15 (1960): 22–30.
  • Piché, Lee A., trans. On the Movement of the Heart (To Master Philip of Castro Caeli). 1992. Typescript.
    (To order, visit the Translation Clearing House.)

De occultis operationibus naturae

De principiis naturae

  • Baldner, Stephen, trans. The Principles of Nature. In his Thomas Aquinas: Basic Philosophical Writing, 45–59. Broadview Editions. Peterborough, Ontario: Broadview Press, 2018.
  • Bobik, Joseph. Aquinas on Matter and Form and the Elements: A Translation and Interpretation of the ‘De Principiis Naturae’ and the ‘De Mixtione Elementorum’ of St. Thomas Aquinas. Notre Dame, Ind.: University of Notre Dame Press, 1998.
    (Includes the Latin.)
  • Bourke, Vernon, trans. On the Principles of Nature. In his The Pocket Aquinas, 61–77. New York: Pocket Books, 1960.
  • Campbell, Gerard T., trans. On the Principles of Nature. E-text, www4.desales.edu/~philtheo/aquinas/Nature.html.
    (Includes facing Latin text.)
  • Clark, Mary T., trans. On the Principles of Nature. In her An Aquinas Reader, 163–77. Garden City, N.Y.: Image Books, 1972.
  • Conway, Pierre H., trans. The Principles of Nature. Columbus, Ohio: College of St. Mary of the Springs, 1963.
  • Goodwin, Robert P., trans. The Principles of Nature. In his Selected Writings of St. Thomas Aquinas: The Principles of Nature, On Being and Essence, On the Virtues in General, On Free Choice, 7–28. The Library of Liberal Arts. Indianapolis: Bobbs–Merrill, 1965.
  • Klima, Gyula, trans. On the Principles of Nature. E-text, faculty.fordham.edu/klima/Blackwell-proofs/MP_C19.pdf.
  • Kocourek, R.A., trans. The Principles of Nature. In his An Introduction to the Philosophy of Nature. St. Paul: North Central Publishing, 1948; revised, 1951; revised, 1956. E-text, isidore.co/aquinas/english/DePrincNaturae.htm and isidore.co/aquinas/DePrincNaturae.htm (bilingual).
    (1948 edition also on CD-ROM from InteLex.)
  • McDermott, Timothy, trans. On the Principles of Nature. In Thomas Aquinas, Selected Philosophical Writings, selected and translated by Timothy McDermott, 67–80. World’s Classics. Oxford: Oxford University Press, 1993.
  • McInerny, Ralph, trans. On the Principles of Nature. In Thomas Aquinas, Selected Writings, edited and translated with an introduction and notes by Ralph McInerny, 18–29. Harmondsworth: Penguin, 1998.
  • Stump, Eleonore and Stephen Chanderbhan, trans. On the Principles of Nature. In Aquinas: Basic Works, ed. Jeffrey Hause and Robert Pasnau. Indianapolis: Hackett, 2014.

De rationibus fidei contra Saracenos, Graecos et Armenos

De regno

  • Blythe, James M., trans. On the Government of Rulers: De Regimine Principum, by Ptolemy of Lucca, with portions attributed to Thomas Aquinas. The Middle Ages Series. Philadelphia: University of Pennsylvania Press, 1997.
    (See Blythe’s introduction, pp. 3–5, and also Eschmann’s, pp. ix–xiv, for the relation between Ptolemy’s and Thomas’ texts and for the confusion about the title of Thomas’ text. Note that the chapter divisions in the text translated by Blythe differ from those in the text translated by Phelan and Eschmann.)
  • Dawson, J.G., trans. In Aquinas: Selected Political Writings, ed. A.P. d’Entrèves. Oxford: Blackwell, 1948; reprint, Totowa, N.J.: Barnes & Noble, 1981, pp. 2–42.
    (Reprint omits the Latin and therefore differs in pagination.)
  • Phelan, Gerald B., and I.T. Eschmann, trans. On Kingship to the King of Cyprus. Mediaeval Sources in Translation, 2. Toronto: Pontifical Institute of Mediaeval Studies, 1949.
    (Also on CD-ROM from InteLex.)
  • Sigmund, Paul E., trans. On Kingship, or, The Governance of Rulers. In his St. Thomas Aquinas on Politics and Ethics: A New Translation, Backgrounds, Interpretations. Norton Critical Edition. New York: Norton, 1988.

De sortibus

  • Carey, Peter Bartholomew, trans. The Opusculum on Lots of St. Thomas. Dover, Mass.: Dominican House of Philosophy, 1963. E-text, isidore.co/aquinas/english/Sortibus.htm and isidore.co/aquinas/Sortibus.htm (bilingual).
  • Carey, Peter, trans. De Sortibus: A Letter to a Friend about the Casting of Lots. Eugene, Ore.: Cascade Books, 2021.
    This is a new translation by the above translator, with essays by various contributors.

De substantiis separatis

  • Lescoe, Francis J., trans. Treatise on Separate Substances. West Hartford, Conn.: Saint Joseph College, 1959. Bilingual e-text, isidore.co/aquinas/SubstSepar.htm.
    (Also on CD-ROM from InteLex.)
  • Lescoe, Francis J., ed. and trans. Tractatus de substantiis separatis. West Hartford, Conn.: Saint Joseph College, 1962.
    (English and Latin.)

Epistola ad comitissam Flandriae

  • Dawson, J.G., trans. ‘On the Government of Jews in Aquinas.’ In Aquinas: Selected Political Writings, ed. A.P. d’Entrèves. Oxford: Blackwell, 1948, pp. 84–95; reprint, Totowa, N.J.: Barnes & Noble, 1981, pp. 43–48.
    (Reprint omits the Latin.)
  • Johnson, Mark, trans. Thomas Aquinas’s Letter to Margaret of Flanders. E-text in various formats at thomistica.net/letter-to-margaret-of-flanders/.

Epistola exhortatoria de modo studendi

  • Kenny, Joseph, trans. Letter of Thomas Aquinas to Brother John on How to Study. E-text, isidore.co/aquinas/DearJohn.htm.
  • McDonald, Hugh, trans. A Letter by Aquinas to Brother John on How to Study. E-text, web.archive.org/web/20160412135452/http://www.hyoomik.com/phi205/memory.htm.
    (Latin and English.)
  • Perkins, Steve, trans. A Letter on the Method of Study. E-text, www.forumromanum.org/literature/aquinas/stud_e.html.
  • Vost, Kevin, trans., in his How to Think Like Aquinas: The Sure Way to Perfect Your Mental Powers. Manchester, N.H.: Sophia Institute, 2018.
  • White, Victor, trans. ‘The Letter of Thomas Aquinas to Brother John De modo studendi.’ Life of the Spirit (Oxford: Blackfriars, Dec. 1944), Suppl. pp. 161–80.
    (Latin and English. English also on CD-ROM from InteLex.)
  • White, Victor, trans. How to Study: Being the Letter of St. Thomas Aquinas to Brother John, ‘De modo studendi.’ 4th ed. London: Blackfriars, 1953.
    (Latin and English.)

Officium de festo Corporis Christi

  • Anderson, Robert, and Moser, Johann, trans. Devoutly I Adore Thee: The Prayers and Hymns of Saint Thomas Aquinas. Manchester, N.H.: Sophia Institute, 1993; revised under the title The Aquinas Prayer Book: The Prayers and Hymns of Saint Thomas Aquinas, Sophia Institute, 2000.
    (Latin and English; includes parts of the liturgy. See also under ‘Orationes’ below.)
  • Kenny, Joseph, trans. Liturgy of Corpus Christi. E-text with images from the Poissy Antiphonary and recordings of the chant, dhspriory.org/thomas/CorpusChristi.htm.
    (Latin and English. Fr. Kenny’s first-hand knowledge of the Dominican liturgy makes this an especially valuable site.)

Orationes

  • Anderson, Robert, and Moser, Johann, trans. Devoutly I Adore Thee: The Prayers and Hymns of Saint Thomas Aquinas. Manchester, N.H.: Sophia Institute, 1993; revised under the title The Aquinas Prayer Book: The Prayers and Hymns of Saint Thomas Aquinas, Sophia Institute, 2000.
    (Latin and English.)
  • Clark, Mary T., Jane Wynne Saul, and Gerard Manley Hopkins, trans. In Clark’s An Aquinas Reader, 533–41. Garden City, N.Y.: Image Books, 1972.
  • Doyle, A.I. ‘A Prayer Attributed to St. Thomas Aquinas.’ Dominican Studies 1 (1948): 229–38.
    (An early English version of ‘Concede mihi.’)
  • www.preces-latinae.org/index.htm links to the Latin and English of Adoro te devote, Lauda Sion, Pange lingua, Sacris solemniis, and Verbum supernum; the site also contains Thomas’ prayers before and after Mass (www.preces-latinae.org/thesaurus/AnteMissam/Aquinas.html and www.preces-latinae.org/thesaurus/PostMissam/Thomae.html).
  • Hopkins, Gerard Manley, trans., modified by Fr. Joseph Kenny [?]. Adoro te devote. Latin and English at isidore.co/aquinas/AdoroTe.htm.

University sermons

Works of uncertain authenticity

De quattuor oppositis

  • Schaller, George, trans. De quattuor oppositis. Dover, Mass: Dominican House of Philosophy, 1963.

Officium de festo S. Augustini

  • Moclair, H., trans. Office for the Feast of St. Augustine, Bishop, Confessor, and Doctor of the Church. In Mary T. Clark, An Aquinas Reader, 541–49. Garden City, N.Y.: Image Books, 1972.

Spurious works

Aurora consurgens

  • Franz, Marie-Louise von, ed. Aurora consurgens: A Document Attributed to Thomas Aquinas on the Problem of Opposites in Alchemy. Translated by R.F.C. Hull and A.S.B. Glover. Bollingen Series, 77. New York: Pantheon, 1966; reprinted as vol. 89 of ‘Studies in Jungian Psychology by Jungian Analysts,’ Toronto: Inner City Books, 2000.
    (English and Latin. A companion work to Jung’s Mysterium coniunctionis, and originally published as the third part thereof.)

De moribus divinis

  • Delaney, B., trans. On the Ways of God. London: Burns & Oates, 1926, and New York: Benziger, 1927.
  • Maritain, Raïssa, and Margaret Sumner, trans. The Divine Ways: A Little Work of Saint Thomas Aquinas. Spiritual Classics Series, 1. Windsor, Ont.: Christian Culture Press, 1942; reprint, London, Ont.: Basilian Press, 1946; reprinted with revisions, Manchester, N.H.: Sophia Institute, 1995.

De sacramento altaris

  • Rawes, H.A., trans. The Bread of Life, or, St. Thomas Aquinas on the Adorable Sacrament of the Altar, Arranged as Meditations, with Prayers and Thanksgivings for Holy Communion. New ed. Library of the Holy Ghost, 1. London: Burns & Oates, and New York: Benziger, 1879 (?); microfiche, American Theological Library Association monograph preservation program, fiche 1986–1028. Electronic version sold by Logos Bible Software.

Expositio in Canticum canticorum

  • Giles of Rome. Commentary on the Song of Songs and Other Writings. Ed. John E. Rotelle. The Augustinian Series, vol. 10. Villanova, Penna.: Augustinian Press, 1998.

Sermons

  • Ashley, John M., trans. The Homilies of S. Thomas Aquinas upon the Epistles and Gospels for the Sundays of the Christian Year, to Which Are Appended the Festival Homilies. 2d ed. London: J.T. Hayes, 1873; reprint, Ft. Collins, Colo.: Roman Catholic Books, 1996. Electronic version of the first, 1867 edition sold by Logos Bible Software.

Abbreviations explained for non-Latinists

Methods of referring to parts of the Summa theologiae

The Summa falls into three parts, of which Thomas subdivides the second into the first part of the second part (in Latin, prima [pars] secundae [partis]) and the second part of the second part (in Latin, secunda secundae). Because Thomas never finished the third part, his followers cut and pasted an ending from his earlier writings; their work is ‘the supplement.’ You will see the following in notes and parenthetical references:

the first part (prima pars)
1; 1a; I; Ia
the first part of the second part
1–2; 1a–2ae; I–II; Ia–IIae
the second part of the second part
2–2; 2a–2ae; II–II; IIa–IIae
the third part (tertia pars)
3; 3a; III; IIIa
the supplement (supplementum)
suppl.

These parts break down into questions (qq.); and each question (in Latin, quaestio, abbreviated q. or quaest.) is comprised of articles (etymologically, ‘little joints’ in the organic whole; a. = article). Most articles contain ‘objections’ (suggested arguments) on one side of an issue, an argument or quotation supporting the other side and introduced with the formula sed contra (‘on the other hand’), Thomas’ solution (solutio) in the body (corpus) of the article, and replies to the objections; replies open with the Latin preposition ad (‘to’ or ‘toward’) followed by an ordinal number (e.g., ad primum means ‘in reply to the first objection,’ while ad tertium indicates the reply to the third). Here are sample citations:

ST 1.3.2c
Summa theologiae, part 1, q. 3, a. 2, corpus
ST 2–2.75.1 ad 3
Summa theologiae, 2nd part of 2nd part, q. 75, a. 1, reply to 3rd objection
ST 3.10.3 sed contra
Summa theologiae, part 3, q. 10, a. 3, the argument on the other side
ST Suppl. 41.2
Summa theologiae, supplement, q. 41, a. 2

Instead of ad 3, you may see ad 3um or ad 3m; the -um or -m represent the Latin declensional ending, as in ad tertium.

Miscellaneous abbreviations for parts of works

c.
caput, ‘chapter’
d.
distinction (a division within commentaries on the Sentences of Peter Lombard, the theological textbook in Thomas’ day)
div. text.
division of the text (Thomas’ outline of the text he’s commenting on)
expos. text.
exposition of the text (Thomas’ detailed interpretation)
lect.
lectio, ‘lesson’ (units of text Thomas comments on; lessons of Aristotle’s works are usually shorter than the chapters modern readers know)
princ.
principium, ‘beginning’
q.a
quaestiuncula, ‘little question,’ an inquiry attached to an article within a question within a distinction

Some common abbreviations for Thomas’ works

You may see the following abbreviations, and many variations on them, in footnotes and in lists of parallel passages. Note well: Even the full titles of Thomas’ works may vary from manuscript to manuscript and, therefore, from edition to edition.

Ad Gal.
on the epistle to the Galatians
Compend. theol.
Compendium theologiae
Cont. err. Graec.
Contra errores Graecorum
Cont. Gent.
Summa contra gentiles
Cont. impug. relig.
Contra impugnantes Dei cultum et religionem
Cont. retrahent. ab ingressu relig.
Contra doctrinam retrahentium a religione
De anima or Super De anima
Sententia super De anima
De caelo or Sent. De caelo
Sententia de caelo et mundo
De dec. praec.
Collationes de decem praeceptis
De duob. praec.
part of Collationes de decem praeceptis, on charity
De div. nom.
Expositio super Dionysium De divinis nominibus
De hebdom. or Super De hebd.
Expositio in librum Boethii De hebdomadibus
De perf. vitae spir.
De perfectione spiritualis vitae
De pot.
De potentia
De spirit. creat.
De spiritualibus creaturis
De unit. intell.
De unitate intellectus contra Averroistas
De verit.
De veritate
De virtut.
De virtutibus in communi
Ethic. or Sent. Ethic.
Sententia libri Ethicorum
Expos. in Orat. Dom.
Collationes super Pater Noster
Expos. in Salut. Angelicam
Collationes super Ave Maria
Expos. super Symb.
Collationes super Credo in Deum
In Boeth. De Trin.
Expositio super librum Boethii De trinitate
In Col.
on the epistle to the Colossians
In Eph.
on the epistle to the Ephesians
In Heb.
on the epistle to the Hebrews
In I Cor. and In II Cor.
on the epistles to the Corinthians
In I Thess. and In II Thess.
on the epistles to the Thessalonians
In I Tim. and In II Tim.
on the epistles to Timothy
In Io. or Super Joh.
Lectura super Johannem. Reportatio
In Iob
Expositio in Job ‘ad litteram’
In Is. or Post. Is.
Postilla super Isaiam, on Isaiah
In Mt. or Super Matt.
Lectura super Matthaeum. Reportatio
In Ps.
Postilla super Psalmos
In Rom.
on the epistle to the Romans
In Tit.
on the epistle to Titus
Metaphys. or Super Meta.
Sententia super Metaphysicam
Periherm.
Sententia super Peri hermenias
Phys. or Super Phys.
Sententia super Physicam
Poster. or Super Post. An.
Sententia super Posteriora Analytica
Q. de anima
Disputed questions De anima
Qq. disp.
Quaestiones disputatae
Quodl.
Quaestiones de quodlibet I–XII
Sent. or Super Sent.
Scriptum super libros Sententiarum

Latin texts & aids

For those who can read Latin

Besides the English translations with facing Latin texts, noted above, the web offers an increasing number of Latin e-texts. Building on Roberto Busa’s work for the Index Thomisticus, Enrique Alarcón has put the writings of Thomas (and some by his contemporaries) as well as many tools for their study on-line and in a most pleasing format at www.corpusthomisticum.org; if your Latin is rusty, double-clicking on any word in Thomas’ text will look it up in Perseus’ Latin Word Study Tool. Also noteworthy is the Catena aurea electronica, in progress at big.hypotheses.org/catena-aurea. Given the vagaries of servers and browsers, it’s good to know other addresses besides, and each of the following has its advantages:

If you have an Android device, a new and free app allows you to read or search the whole Summa theologiae, in the text from Corpus Thomisticum, even while offline; another app does the same for all of Thomas’ works. See www.corpusthomisticum.org/eandroid.html for full information.

For those who wish they could read Latin

Thomas kept his Latin simple and straightforward, wanting nothing to come between his readers and truth. Consequently, learning enough Latin to consult his works in the original takes far less time and effort than learning to read Cicero or Livy or Vergil. You can do it, and on-line resources can help. Start with this tutorial for beginners in medieval Latin (it presupposes no knowledge of classical Latin), and then explore these aids:

Dictionaries

The Perseus Digital Library at Tufts University provides many tools for students of classical Latin, among other things:

  • A good starting place is Lewis’s An Elementary Latin Dictionary.
  • For more detail, use Lewis & Short’s A Latin Dictionary, either browsing through it or looking up a particular word.
  • Have declensions and conjugations so confused you that you don’t even know where to look in the dictionary? Perseus will take the term which perplexes you and tell you which words it could be a form of.
  • Perseus lets you go from English to Latin as well as from Latin to English.

‘Reports of my death have been greatly exaggerated,’ said Mark Twain, and we might say something similar about Latin. Like a living thing (if only of the slow-moving sort), Latin changed during the Middle Ages, and even today it acquires new words. When you read medieval or later authors, you will find that, sooner or later, dictionaries of classical Latin let you down, and you will want resources which take post-classical developments into account:

  • Roy J. Deferrari’s A Latin–English Dictionary of St. Thomas Aquinas (Boston: St. Paul Editions, 1960) is not on-line but deserves mention anyway as the most useful dictionary for beginners in Aquinas’s Latin. It is a portable adaptation of Deferrari’s multi-volume A Lexicon of St. Thomas Aquinas, the difference being that the Lexicon reproduces texts illustrating the various meanings of words, while the Dictionary just lists the possible meanings. Both are based principally on the Summa theologiae. Preserving Christian Publications has a 2004 reprint of the Lexicon; for availability of the Dictionary, see isbn.nu/0819844438/price.
  • Not specifically about Thomas’ usage but easy to use and still in print is Leo F. Stelten’s Dictionary of Ecclesiastical Latin (Peabody, Mass.: Hendrickson, 1995).
  • William Whitaker’s downloadable dictionary (mk270.github.io/whitakers-words), like the Perseus site mentioned above, allows you to search by the word as you see it, even if you don’t know the form under which its dictionary entry would appear. Those who cannot or would rather not download the program can use it on-line, by way of the web. Ian Douglas Scott has developed an Android app.
  • There’s a handy list of ‘The Hard Little Words: Prepositions, Adverbs, Conjunctions (With Some Definitions of Medieval Usage)’ at thevore.com/the-hard-little-words-prepositions-adverbs-conjunctions/.
  • The word-study tools at latinlexicon.org and Logeion often include post-classical usage.
  • Lynn Nelson’s Latin Word List has many addresses and at least three versions, and since other sites may link to any one of them, it may prove useful to sort them out here.
    1. The most recent appears to be the 8,000-entry list at humanum.arts.cuhk.edu.hk/Lexis/Latin.
    2. An older, 5,000-entry list seems to underlie the searchable list at archives.nd.edu/latgramm.html, a site still worth knowing about because of its many other features.
    3. The HTML presentation at www.math.ubc.ca/~cass/frivs/frivolities.html seems based on the oldest, 3,469-entry list.
  • If you develop an interest in medieval Latin beyond what you need for reading Aquinas, see the guides to printed and on-line dictionaries at www.ucc.ie/en/cnls/links/ and bcs.fltr.ucl.ac.be/DicLanALat.html; they will lead you to Latin–Latin dictionaries, dictionaries of Latin place-names, explanations of ecclesiastical abbreviations, and many other remarkable tools.
  • JLearnIt software for studying vocabulary (whether English, French, Spanish, Dutch, German, Italian, Hebrew, Portuguese, Swedish, Danish, Norwegian, Hungarian, Russian, Latin or Czech), runs on many operating systems.

Grammars

  • For a clear and wonderfully concise grammar of classical Latin, see Charles E. Bennett’s New Latin Grammar (also at www.textkit.com and, in several formats, at www.gutenberg.org).
  • Winfred Lehmann and Jonathan Slocum maintain Latin Online at the Linguistics Research Center of the University of Texas at Austin.
  • For answers to more grammatical questions than Aquinas’s style could ever occasion, see Allen & Greenough’s Latin Grammar (also at www.textkit.com as a PDF file).
  • When Allen & Greenough’s classic is too much, try Anne Mahoney’s Overview of Latin Syntax.
  • If you need just a little something to jog your memory, try Lynn Nelson’s reference list of Latin grammar.
  • Not on-line but still in print and noteworthy for present purposes is John F. Collins’ A Primer of Ecclesiastical Latin (Washington, D.C.: The Catholic University of America Press, 1985), which does not presuppose knowledge of classical Latin.

Other resources

  • William Harris’s site contains a wealth of essays about how to approach the study of Latin, as well as Latin texts with commentary.
  • Claude Pavur’s collection of ‘Latin Teaching Materials at Saint Louis University,’ goes especially well with Wheelock’s Latin; notice also the ‘Reading Acceleration Machine’ freeware.
  • When learning any language, practice reading with biblical and liturgical texts, because their familiarity allows you to pick up speed.
  • Haunting vocal music helps fix the patterns of a language in one’s memory. Try discs of Gregorian chant with both English and Latin in the liner notes. A personal favorite among more recent compositions is Igor Stravinsky’s opera-oratorio, Oedipus Rex; the Philips recording (438 865–2) features singers with especially clear enunciation and a booklet with parallel Latin and English.
  • Anthologies and readers often include valuable introductions and notes. An especially good one for philosophers and theologians is The Confessions of St. Augustine: Books I–IX (Selections), with introduction, notes, and vocabulary by James Marshall Campbell and Martin R.P. McGuire (Englewood Cliffs, N.J.: Prentice–Hall, 1931, but still in print thanks to Bolchazy–Carducci, whose catalog every Latinist will want to peruse).
  • Anyone considering advanced study of medieval Latin should consult Medieval Latin: An Introduction and Bibliographical Guide, ed. F.A.C. Mantello and A.G. Rigg (Washington, D.C.: The Catholic University of America Press, 1996); its essays survey developments in grammar, vocabulary, spelling, pronunciation, style, and literature in areas from philosophy to textiles.

More sites of interest

Early Christian writers

Medieval authors

Middle Ages

  • The Labyrinth will help you find your way amid things medieval. (No longer maintained.)
  • Paul Halsall’s Internet History Sourcebooks Project includes a rich collection of medieval texts.

Islamic philosophy

On St. Thomas