Here’s a list of legally free ebooks on Catholic Christian apologetics, which we have indexed as of 03 April 2011 (not including ebooks on church history and church-science relations). The updated and more complete list of apologetics texts on our blog may be found at the Apologetics page.

  1. 455 Selected Articles from… Annals Australasia… and various pamphlets…, by Dr. Leslie Rumble, Fr. Paul Stenhouse, Ph.D., et al. Available online at Sean O Lachtnain’s Home Page. [N.B., This provides access to many very useful resources on faith, morals, and apologetics. The webpage title is actually: “455 Selected Articles from Back Issues of “Annals Australasia”—formerly known as “Annals Australia”, “Radio Replies” and the two ancillary volumes, and Various Pamphlets by former Editor of “Annals” — Dr. Leslie Rumble, and Current Editor of “Annals” and Author of Catholic Answers to “Bible” Christians- available from Chevalier Press by Fr. Paul Stenhouse, M.S.C., Ph.D. — Current “ANNALS” Editor”].
  2. Address of the Roman Catholics to their fellow citizens, of the City and State of New York (1840). Available at Internet Archive.
  3. Against Heresies, or Refutation and Overthrow of Knowledge falsely so-called [or, Adversus Haereses], by St. Irenaeus of Lyons (c.180 AD), trans. Alexander Roberts and William Rambaut; from Ante-Nicene Fathers, Vol. 1, eds. Alexander Roberts, James Donaldson, and A. Cleveland Coxe (Buffalo, NY: Christian Literature Publishing Co., 1885). May be read online at New Advent (rev. and ed. Kevin Knight), with active links to relevant Catholic Encyclopedia articles and Scripture passages; and on The Augustine Club. On Apologetics, Salvation, Heresy, Cosmology, Gnosticism, Divine Revelation, Bishops, Roman Primacy, Tradition, Sacraments, etc. [NB, A defense of Christianity against Gnosticism, which also shows that the early Church had a Catholic view of sacramental grace, the Roman primacy, the bishops as successors of the apostles, etc. Books I and II are somewhat difficult summaries of Gnostic beliefs to be refuted, so it may be better to start with Book III, which begins the summary of Christian teaching.]
  4. [Against the Errors of the Greeks] Contra Errores Graecorum, by St. Thomas Aquinas, O.P., translated by Peter Damian Fehlner, F.I., re-edited and missing chapters supplied by Joseph Kenny, O.P. May be read online at DHS Priory of the Immaculate Conception.
  5. And You Will Know the Truth: How to Defend and Explain the Catholic Faith, by Sebastian R. Fama. Available at Internet Archive in multiple formats. Apologetics.
  6. Answers to a Jewish enquirer, by Théodore Ratisbonne (London: Catholic Truth Society, 1920). Available at Internet Archive in multiple formats (Digitizing sponsor: MSN, Book contributor: Kelly Library, University of Toronto). Apologetics, Evangelization, Judaism.
  7. Apologetica; elementary apologetics for pulpit and pew, by Patrick Albert Halpin (New York, J.F. Wagner, 1905). With Imprimatur. Available at Open Library and Internet Archive (Digitizing sponsor: The Library of Congress, Book contributor: The Library of Congress) with a second copy here.
  8. Apologetics and Evangelism for Catholics, by Adadzie, Godwin Delali (GADEL). Available at Internet Archive. A short tract that aims “to demonstrate some Scriptural texts that support some Catholic beliefs and practices, hence answering common objections non-Catholic Christians hold against the Catholic Church”.
  9. On the Apostolical and Infallible Authority of the Pope: when Teaching the Faithful, and on his Relation to a General Council, Francis Xavier Weninger (New York : D.& J. Sadlier ; Cincinnati, OH : J.P. Walsh, 1868). Available at Internet Archive and Open Library. [N.B., It has no Imprimatur, but the author is stated to be a missionary of the Society of Jesus {when the members of that order were still reliably orthodox}, and the content appears to be a faithfully Catholic demonstration from faith, history and reason of papal infallibility.]
  10. The Beauty and Truth of the Catholic Church: Sermons from the German, adapted and edited, Volume II, by the Rev. Edward Jones, with an Introduction by the Most Rev. John Ireland (St. Louis, London: B. Herder, 1913). With Imprimatur. Available at Internet Archive [N.B., This volume collects discourses on the sacraments of baptism, confirmation, and the Eucharist.]
  11. The Beauty and Truth of the Catholic Church: Sermons from the German, adapted and edited, Volume III, by the Rev. Edward Jones, with an Introduction by the Most Rev. John Ireland (Freiburg (Baden); St. Louis, Mo.; London: B. Herder, 1913). With Imprimatur. Available at Internet Archive and Open Library  [N.B., This volume collects discourses on the sacraments of penance, matrimony, orders, and unction, and on education. The OL index age incorrectly provides the image of Volume II.]
  12. The Beauty and Truth of the Catholic Church: Sermons from the German, adapted and edited, Volume IV, by the Rev. Edward Jones, with an Introduction by the Most Rev. John Ireland (St. Louis, Mo.; London: B. Herder, 1916). With Imprimatur. Available at Internet Archive [N.B., This volume collects discourses on God, Christ, and grace.]
  13. The Beauty and Truth of the Catholic Church: Sermons from the German, adapted and edited, Volume V, by the Rev. Edward Jones, with an Introduction by the Most Rev. John Ireland (St. Louis, Mo.; London: B. Herder, 1916). With Imprimatur. Available at Internet Archive [N.B. This volume includes discourses on the moral law and the last things.]
  14. The Bible and Rationalism; or, Answer to Difficulties in the Books of Moses, by John Thein. (St. Louis, Mo., B. Herder, 1901). Part 1 of 4. With Imprimatur. Available on Internet Archive [N.B. Actually Part I but the Internet Archive index page says it’s Volume III.]
  15. The Bible and Rationalism; or, Answer to Difficulties in the Historical, Didactic, and Prophetical Books of the O.T. [Old Testament], by John Thein. (St. Louis, Mo., B. Herder, 1901). Part 2 of 4. With Imprimatur. Available at Internet Archive.
  16. The Bible and Rationalism; or, Answer to Difficulties in the Books of the New Testament, by John Thein. (St. Louis, Mo., B. Herder, 1901). Part 3 of 4. With Imprimatur. Available on Open Library and Internet Archive [N.B. Actually Part III but the index page image is incorrectly that of Volume IV.]
  17. The Bible and Rationalism; or, Answer to Difficulties in the Mosaic Cosmogony, Anthropology, and Biblical Chronology, by John Thein. (St. Louis, Mo., B. Herder, 1901). Part 4 of 4. Concerns the Bible and scientific theories. With Imprimatur. Available on Internet Archive.
  18. The Bible and the Rule of Faith, by Abbe Louis Nazaire Bégin, translated by G.M. Ward (London, Burns and Oates; Quebec: John Barrow, 1875). With Imprimatur. Available in various formats at Internet Archive and Open Library
  19. Birth control: a statement of Christian doctrine against the Neo-Malthusians, by Sutherland, Halliday (New York : P. J. Kenedy & sons, 1922). Available at Manybooks.net, Internet Archive and Open Library. Apologetics, Bioethics, Ethics, Morals.
  20. A Calendar of Scottish Saints, Second Edition Revised & Augmented, by Dom Michael Barrett, O.S.B. (Fort-Augustus: Abbey Press, 1919). With Imprimatur. Available in many formats at Manybooks.net.
  21. Catechism: doctrinal, moral, historical, and liturgical: with answers to the objections drawn from the sciences against religion, by Patrick Power (Dublin: J. Duffy; London: Burns and Oates, 1905). With episcopal approbation. Available at Internet Archive and Open Library (Digitizing sponsor: MSN, Book contributor: Kelly Library, University of Toronto).
  22. Catena aurea or, A golden chain of evidences demonstrating from “analytical treatment of history,” that papal infallibility is no novelty; a memorial of the Papal jubilee, June 16, 1871 to honor the “Annos Petri completos” of our Holy Father, Pope Pius the Great,by an Old Catholic (Perry County, Ohio: St. Joseph’s College, 1871).  Available in various formats at Open Library and Internet Archive. [N.B., While author refers to himself as an “Old Catholic”, this appears to be an ironic use of the term, since the work sets out to refute the thesis of Dollinger and the “Old Catholic” sect. The work is therefore orthodox. However, please exercise caution in view of certain statements tending to anti-Semitism.]
  23. Cathedra Petri: or, The titles and prerogatives of St. Peter, and of his see and successors; as described by the early fathers, ecclesiastical writers, and councils of the church, by C.F.B. Allnatt (London: Burns and Oates, 1883). Available at Internet Archive and Open Library. The 1879 edition is available at Internet Archive and Open Library.
  24. “Catholic”: an essential and exclusive attribute of the true Church, by Monsignor Thomas John Capel. (New York: Wilcox & O’Donnell, 1884) Available at Internet Archive and Open Library. No Imprimatur, but the author is domestic prelate of Pope Leo XIII, and its content is Catholic.
  25. The Catholic Church and the Gospels, by Charles G. Mortimer (Dublin: Catholic Truth Society of Ireland). Available at Lux Occulta
  26. Catholic Common Sense, by Albert Power (Dublin: Catholic Truth Society of Ireland, 1947). Available on Lux Occulta (copyright status uncertain).
  27. The Catholic Controversy, by Saint Francis de Sales, Bishop and Doctor of the Church, translated by Rev. Henry Benedict Mackey, O.S.B.  (London: Burns and Oates, 1886). May be read online at Good Catholic Books. The 3rd revised and augmented edition, with an excellent translator’s preface (New York, Cincinnati, Chicago: Benziger Brothers; London: Burns and Oates, 1909) (Library of St. Francis De Sales, volume III) is available in various formats at Internet Archive.
  28. Catholic Controversy: a Reply to Dr. Littledale’s Plain Reasons, by Henry Ignatius Dudley Ryder, 1837-1907 (London: Burns and Oates, 1881). Available on Open Library and Internet Archive (Digitizing sponsor: MSN; Book contributor: Kelly Library, University of Toronto). The 1889 edition (London: Burns & Oates; New York: Benziger Brothers, 1889) is available on Open Library and Internet Archive (Digitizing sponsor: National Institute for Newman Studies; Book contributor: Saint Mary’s College of California).
  29. The Catholic Doctrine of the Eucharist: demonstrably proved from Scripture, from Tradition, and from the writings of some of the most eminent Catholic and Protestant authors who have treated on the subject; in sixteen letters, with notes and appendices, addressed to the Lord Bishop of Exeter; and dedicated by permission to His Imperial and Royal Majesty the Emperor of Austria, King of Hungary, Bohemia, etc., by M.D. Talbot (London: T. Jones, 1844). Available in various formats at Internet Archive and Open Library.
  30. Catholic Evidence Training Outlines, compiled by Maisie Ward, with a foreword by His Eminence Cardinal Bourne, Archbishop of Westminster (London: Sheed & Ward, 1925, fifth impression 1929). With Imprimatur. May be read online at the EWTN Library. “No one should attempt to use this book without having made a careful study of the Introduction. The speakers are again reminded that these are not street-corner outlines but class outlines to prepare them for the street corner.”
  31. Catholic Fiction part 1 Booklet, by Godwin Delali Adadzie. Available on Internet Archive, which described the tract thus: “Is the Roman Catholic Church the whore of Babylon? How to refute the claim that Bible Prophecy Reveals Next And Last Pope Will Be A Devil Impersonating John Paul II. Courtesy of the Sts. Peter and Paul Catechism Ministry – Ghana. website: http://www.amen.co.nr. Follow us on http://www.twitter.com/Apologetics”
  32. Catholic Moral Teaching and its Antagonists Viewed in the Light of Principle and of Contemporaneous History, by Joseph Mausbach, translated from the 6th edition by Anna M. Buchanan (New York: J. F. Wagner, 1914). With Imprimatur. Available on Open Library and Internet Archive (Digitizing sponsor: MSN; Book contributor: Kelly Library, University of Toronto).
  33. The Catholic’s ready answer; a popular vindication of Christian beliefs and practices against the attacks of modern criticism, by Michael Peter Hill, from the Modernes A B C by Franz Xaver Brors (New York, Cincinnati: Benziger Brothers, 1915). With Imprimatur. Available at Open Library and Internet Archive.
  34. Catholic tracts, by John Thayer, Thomas Kelly (Baltimore : E. Cummiskey). No Imprimatur, but with a recommendation from Francis Patrick Kenrick, Bishop of Arath and Coadjutor Bishop of Philadelphia. Apologetics, Converts. Available at Open Library and Internet Archive (Digitizing sponsor: MSN, Book contributor: Kelly Library, University of Toronto).
  35. Certain difficulties felt by Anglicans in Catholic teaching considered: in a letter addressed to the Rev. E.B. Pusey, on occasion of his Eirenicon of 1864; and in a letter addressed to the Duke of Norfolk, on occasion of Mr. Gladstone’s Expostulation of 1874, by John Henry Newman, 1801-1890 (London: Pickering, 1876). Available on Internet Archive and Open Library (Book contributor: University of Toronto).
  36. The chair of Peter or the Papacy: considered in its institution, development, and organization, and in the benefits which, for over eighteen centuries, it has conferred on mankind, by Murphy, John Nicholas (London: Burns & Oates, 1888). Available at Internet Archive.
  37. The chief points of difference between the Catholic and Protestant creeds, by F. Laun. (New York: J. F. Wagner, 1915). With Imprimatur. May be read online or downloaded in multiple formats at Open Library.
  38. Christian Apologetics; a Defense of the Catholic Faith, by Walter Devivier, 1833-1915, edited by Sebastian Gebhard Messmer, 1847-1930 (New York, Cincinnati, Chicago: Benziger Brothers, [c1903]). With Imprimatur. Available on Open Library and Internet Archive; and may be read on Catholic Tradition.
  39. Christ’s kingdom on earth: or, the Church and her divine constitution, organization, and framework, explained for the people, by James Luke Meagher, 1848-1920 (New York : Christian Press Association, 1891). With Imprimatur. Available at Internet Archive.
  40. A Catholic Critique of Jehovah’s Witnesses (Knights of Columbus, 1963). Available at Internet Archive in multiple formats
  41. Catholic Christianity: or, The reasonableness of our religion, by Oliver Rodie Vassall-Phillips (London: R. & T. Washbourne, 1916) Available at Internet Archive.
  42. Catholic Apologetics Guide 101, by Godwin Delali Adadzie. Available at Internet Archive. Apologetics.
  43. The Catholic Church and Conversion, by G.K. Chesterton. Available on G. K. Chesterton’s Works on the Web. Conversion.
  44. Catholicism Frequently Asked Questions, by Godwin Delali Adadzie (GADEL). Available at Internet Archive. A tract for Catholic evangelization.
  45. Christian anthropology, by John Thein, with an introduction by Prof. Chas. G. Herbermann, Ph.D. (New York, Cincinnati: Benziger Brothers, 1892). Available at Internet Archive. [N.B., No Imprimatur, but it is published by a reputable Catholic publisher, and the content appears to be Catholic.]
  46. A Christian apology: Volume 1, God and Nature, by Paul Schanz, translated by Michael F. Glancey and Victor J. Schobel (Ratisbon, Rome, New York, Cincinnati: Frederick Pustet & Co., 1891). Available in various formats at Open Library and Internet Archive.
  47. A Christian apology: Volume 2, God and Revelation, by Paul Schanz, translated by Michael F. Glancey and Victor J. Schobel (Ratisbon, Rome, New York, Cincinnati: Frederick Pustet & Co., 1891). Available in various formats at Internet Archive, with a second copy here.
  48. A Christian apology: Volume 3, The Church, by Paul Schanz, translated by Michael F. Glancey and Victor J. Schobel (Ratisbon, Rome, New York, Cincinnati: Frederick Pustet & Co., 1891). Available in various formats at Open Library and Internet Archive.
  49. The Church; or, What do Anglicans Mean by the Church? Second edition, by John B. Bagshawe (London: Catholic Truth Society, 1899). With Imprimatur. Available in various formats at Internet Archive.
  50. The Civilizers of the Philippines. Subtitled on the first contents page as “Statements concerning the Roman Catholic Church in the Philippine Islands”. Available in various formats as Internet Archive and Open Library. [N.B., This is a history of the religious orders in Spanish Philippines, and an explanation of their role in its evangelization, education, and socio-economic life.]
  51. A Commentary by Writers of the First Five Centuries on the Place of St. Peter in the New Testament: and that of St. Peter’s successors in the Church, by James Waterworth (London: Thomas Baker, 1871). Available at Internet Archive and Open Library.
  52. Commonitory, For the Antiquity and Universality of the Catholic Faith Against the Profane Novelties of All Heresies, by St. Vincent of Lerins, died c. 450 AD. Available at New Advent.
  53. Concerning the Bible: its use and abuse, John Stephen Vaughan (London : R. & T. Washbourne; New York: Benziger, 1904). With Imprimatur. Available at Open Library and Internet Archive (Digitizing sponsor: MSN, Book contributor: Kelly Library, University of Toronto).
  54. “Contraception and the Infallibility of the Ordinary Magisterium,” by Germain Grisez and John C. Ford, S.J., Theological Studies, 39 (1978): 258–312. Available in PDF format at The Way of the Lord Jesus (copyright 2009).
  55. Contraception and the Natural Law, by Germain Grisez (Milwaukee: Bruce, 1965). Available in PDF format at The Way of the Lord Jesus (copyright 2009).
  56. The Divinity of Christ, by Joseph Rickaby, S.J.  (London, Edinburgh: Sands & Company; St. Louis, Mo.: B. Herder, 1906). With Imprimatur. Part of the Westminster Lectures (Second Series), edited by the Rev. Francis Aveling. Available in various formats at Open Library and Internet Archive.
  57. Ecce Fides-Pillar of Truth, by Fr. John J. Pasquini. Available at Internet Archive in multiple formats. Apologetics
  58. An Essay on the Development of Christian Doctrine, John Henry Newman. On Fundamental Theology, Revelation, Tradition, Ecclesiology. May be read online on Newman Reader (electronic copyright, The National Institute for Newman Studies, 2007).
  59. The Essentials of Spiritual Unity, by Ronald Knox. Available at Catholic Answers (last visited December 8, 2009).
  60. Eucharistica; or, a Series of Pieces, original and translated, on the Most Holy and Adorable Sacrament of the Eucharist, by Most Rev. W. [William] Walsh, Archbishop of Halifax (New York: Edward Dunigan & Brother, 1854). Available in various formats at Internet Archive and Open Library.
  61. Eugenics and Other Evils, by G.K. Chesterton (1922). Available at Manybooks.net and Project Gutenberg. Audiobook available at LibriVox.org.
  62. The Evidence for the Papacy: as Derived from the Holy Scriptures and from Primitive Antiquity, with an Introductory Epistle, by Colin Lindsay (London: Longmans, Green, & Co., 1870). Available at Internet Archive and Open Library.
  63. Explanation of Catholic Morals: A Concise, Reasoned, and Popular Exposition of Catholic Morals, by John Stapleton. Available at Internet Archive and Project Gutenberg.
  64. The exercise of faith impossible except in the Catholic Church, by William G. Penny (1846). Available at Internet Archive and Open Library. [NB, No Imprimatur, but the content appears to be a faithful restatement of Catholic teaching in response to Protestant objections, as well as an explanation of why the author was moved by grace to become Catholic.]
  65. The Faith of Our Fathers, being a plain exposition and vindication of the Church founded by Our Lord Jesus Christ, James Gibbons. Available in multiple formats at Project Gutenberg and: Internet Archive (Book contributor: Project Gutenberg), with a 2nd copy and a 3rd copy at Internet Archive.
  66. Fifty reasons why the Roman Catholic religion ought to be preferred to all others: by which His Most Serene Highness Anthony Ulrick, Duke of Brunswick and Lunenburg, was induced to abjure Lutheranism : to which are added, three valuable papers, etc., etc., etc., by Anton Ulrich, Herzog von Braunschweig-Wolfenbüttel, 1633-1714. On Apologetics, Dogma. May be read online or downloaded in multiple formats at at Internet Archive. [NB: This is still on my Doctrinal Rechecking list, because Internet Archive’s author list mentions Fenelon. But I’ve seen no heterodoxy so far.]
  67. Four Great Evils of the Day, by Henry Edward Manning (London: Burns, Oates, and Co., 1871). Available at Internet Archive and Open Library. [N.B. Lectures on “The Revolt of the Intellect against God”, “The Revolt of the Will against God”, “The Revolt of Society from God”, and “Spirit of Antichrist”]
  68. The Fundamental Fallacy of Socialism: an Essay on the Question of Landownership, Comprising an Authentic Account of the Famous McGlynn Case, edited by Arthur Preuss (St. Louis, Mo.; Freiburg (Baden): B. Herder, 1908). With Imprimatur. Available in various formats at Internet Archive and Open Library
  69. The Future Life: According to the Authority of Divine Revelation, the Dictates of Sound Reason, the General Consent of Mankind, by Joseph Casimir Sasia, 1843-1928 (New York, Cincinnati, Chicago: Benziger brothers, 1918). With Imprimatur. Available on Internet Archive and Open Library (Digitizing sponsor: MSN; Book contributor: Kelly Library, University of Toronto).
  70. Galileo and His Condemnation, by Ernest R. Hull (London: Catholic Truth Society, 1913). Available at Internet Archive and Open Library.
  71. God, Man and Religion: being part I of a short apologetic series, by Ernest R. Hull, S.J. (Bombay: Examiner Press; New York: P.J. Kenedy & Sons; etc., 1914). Available at Internet Archive and Open Library
  72. The Grounds of Faith: Four Lectures delivered in St. George’s Church, Southwark [or, Manning’s Lectures on the Grounds of Faith], by Henry Edward Manning (London: Burns and Lambert, 1852). Available at Open Library and Internet Archive. [Listed on the Table of Contents are: Revealed truth definite and certain; The church a historical witness; The church a divine witness; Rationalism the legitimate consequence of private judgment]
  73. The grounds of the Catholick doctrine: contained in the profession of faith, publish’d by Pope Pius the Fourth, by way of question and answer Richard Challoner, 1691-1781; Pope Pius IV, Pope (Preston [England]: W. Stuart, 1775). Available on Internet Archive.
  74. Heretics, by G.K. Chesterton. Available in multiple formats at Manybooks. and Project Gutenberg. Audiobook available at LibriVox.org.
  75. The History of Heresies and Their Refutation, by St. Alphonsus Maria de Liguori. Available in PDF format at Documenta Catholica Omnia, and may be downloaded in PDF format through the Saints’ Books index.
  76. I’m Glad You Asked: Questions from the parishioners of St. Charles Borromeo Catholic Church, Picayune, Mississippi [N.B. This 127-page booklet compiles a wide range of questions and answers on the Catholic Faith, which appears useful for religious teaching, evangelization and apologetics.] Available at the the website of the Saint Charles Borromeo Catholic Church.
  77. In Soft Garments: A Collection of Oxford Conferences, by Ronald A. Knox (New York: Sheed & Ward, 1953). With Imprimatur. Available at Internet Archive. Includes the essays “If God exists”, “The Living Witness”, “The Unholiness of the Church”, “Verbum baro factum est”, “The Church and Human Progress”, and “Unselfishness in Marriage”.
  78. Indulgences: Their Origin, Nature, and Development, by Alexius M. Lépicier (Alexis-Henri-Marie Cardinal Lépicier), (London : Kegan Paul, Trench, Trübner 1895). With approbation. Available at Open Library. And Internet Archive.
  79. The Inquisitiona Critical and Historical Study of the Coercive Power of the Churchby E. Vacandard, translated from the 2d ed. by Bertrand L. Conway. (New York, London, Bombay, Calcutta: Longmans, Green, and Co., 1908). With Imprimatur. Available in various formats at Internet Archive and Open Library.
  80. Instruction on Infant Baptism, by the Sacred Congregation for the Doctrine of the Faith, approved by Pope Blessed John Paul II, October 20, 1980. May be read online at the EWTN Library and the Catholic Information Network.
  81. Knights of Columbus vs. criminal libel and malicious bigotry (Boston, Washington Press, 1914). At Internet Archive and Open Library (Digitizing sponsor: Internet Archive, Book contributor: University of Notre Dame Hesburgh Libraries).
  82. Lectures, by Henry Edward Manning (Baltimore: J.B. Piet). Includes: The Four Great Evils of the Day, The Sovereignty of God, and The Grounds Of Faith. Available at Internet Archive and Open Library.
  83. Lectures: The Four Great Evils of the Day, The Sovereignty of God, The Grounds Of Faith, by Henry Edward Cardinal Manning (New York: P. J. Kenedy & Sons). Available at Internet Archive and Open Library.
  84. [Letter to William Palmer, 1st] A Letter to the Rev. William Palmer, M.A., of Worcester College, Oxford, by Verax, a Catholic layman (London: T. Jones, 1841). Available in various formats at Internet Archive and Open Library.
  85. [Letter to William Palmer, 2nd] Second Letter to the Rev. William Palmer, M.A., of Worcester College, Oxford: demonstratively proving the Church of England to be an heretical and schismatical church, the mere creature of human invention, by Verax, a Catholic layman (London: T. Jones, 1841). Available in various formats at Internet Archive and Open Library.
  86. [Letter to William Palmer, 3rd] Third letter to the Rev. William Palmer, M.A., of Worcester College, Oxford: on auricular confession, and the absolute necessity thereof ; also the nullity of the Church of England’s ordinations, notes, etc., by Verax, a Catholic layman (London: T. Jones, 1841). Available in various formats at Internet Archive and Open Library.
  87. [Letter to William Palmer, 4th] Fourth letter to the Rev. William Palmer, M.A., of Worcester College, Oxford: on the way to find the true church of Christ on earth, on satisfaction, on indulgences, on the supremacy of the See of Rome, infallibility, Eucharist, etc., etc., by Verax, a Catholic layman (London: T. Jones, 1842). Internet Archive and Open Library.
  88. [Letter to William Palmer, 5th] Fifth letter to the Rev. William Palmer, M.A., of Worcester College, Oxford: God has confided the sacred deposit of the revelation of Christianity to an infallible authority, by Verax, a Catholic layman (London: T. Jones, 1843) Available in various formats at Internet Archive and Open Library.
  89. Letters on the Spanish Inquisition, by Joseph de Maître, with notes by John Fletcher (London: Keating; Dolman; Jones; 1838). May be read online and downloaded in various formats at Open Library and Internet Archive. A translation by T.J. O’Flaherty, S.E.C. entitled Letters on the Spanish Inquisition; a rare work, and the best which has ever appeared on the subject (Boston: Patrick Donahoe, 1843) may be read at Google Books. [N.B. This work is sometimes entitled Letters to a Russian Gentleman on the Spanish Inquisition, as in the 1851 translation by the Rev. Aeneaus Mcd. Dawson.]
  90. Living Tradition: Organ of the Roman Theological Forum, no. 25 (September 1989). Contains “Faith, Works and Justification”, by Brian W. Harrison, and “Wolfgang Smith: Teilhardism and the New Religion”, a review by John F. McCarthy. Available at the Roman Theological Forum.
  91. Luther’s own statements concerning his teaching and its results,Taken exclusively from the earliest and best editions of Luther’s German and Latin works , by Martin Luther, 3rd ed. by Henry C. O’Connor. (New York: Benziger Brothers, 1885) With the approbation of various bishops. Available in various formats at Open Library and Internet archive with a second copy at Open Library and Internet Archive. NB, Recommended for Catholics and non-Catholics alike.
  92. A manual of apologetics, by Franz Xavier Jos. Koch, translated by Anna Maud Buchanan, ed. Charles Paul Bruehl (New York, J. F. Wagner, 1915). With Imprimatur. Apologetics. Available at Internet Archive (Digitizing sponsor: Google) and Open Library.
  93. Miscellanies, Volume 1, by Henry Edward Manning (London: Burns and Oates, 1877). Available at Internet Archive and Open Library.
  94. Miscellanies, Volume 2, by Henry Edward Manning (London: Burns and Oates, 1877). Available at Internet Archive and Open Library.
  95. Miscellanies, Volume 3, by Henry Edward Manning (London: Burns and Oates, 1877). Available at Internet Archive and Open Library.
  96. Most Apologetics Collection, from Fr. William Most. ZIP file containing 57 essays by Fr. William Most on subjects relating to apologetics. May be downloaded from EWTN Library.
  97. The New Conspiracy Against the Jesuits Detected and Briefly Exposed, with a Short Account of their Institute; and Observations on the Danger of Systems of Education Independent of Religion, by R. C. Dallas (London, 1815). Available at ManyBooks.net and Project Gutenberg.
  98. On Holy Images (Followed by Three Sermons on the Assumption), by St. John of Damascus (7th-8th century AD), translated from the original Greek by Mary W. Allies (London: Thomas baker, 1898). With Imprimatur. Available at Internet Archive and Open Library.
  99. Orthodoxy, by G.K. Chesterton. Apologetics, Morals. Available at ManyBooks.net and Project Gutenberg as well as at The Literature Network and G. K. Chesterton’s Works on the Web. Audiobook available at LibriVox.org and LibriVox.org (2nd copy).
  100. Our Christian Heritage, by James Cardinal Gibbons (Baltimore: John Murphy and Company; London: R.Washbourne, 1889). Available at Internet Archive with a 2nd copy here.
  101. The Papal Sovereignty; Viewed in its Relations to the Catholic Religion, and to the Law of Europe, by Bishop Felix Antoine Philibart Dupanloup (London : Catholic Publishing & Bookselling company 1860). Available at Open Library and Internet Archive
  102. Paradoxes of Catholicism, by Robert Hugh Benson (New York: Longmans, Green, 1913). Available on Project Gutenberg and Internet Archive (Digitizing sponsor: MSN; Book contributor: Kelly Library, University of Toronto).
  103. Pillar of Fire, Pillar of Truth, by Karl Keating, Catholic Answers. (Copyright 1993 Catholic Answers, Inc). Available on the EWTN Library, which states: “This text file may be uploaded to and downloaded from computer bulletin board systems provided the text is in no way altered and the above copyright notice and address of Catholic Answers are included.”).
  104. Priest and parson : or, Let us be one, by Fogarty, James Henry. (New York: Christian Press Association, 1908). With Imprimatur. Available at Internet Archive (Contribited by Kelly Library, University of Toronto).
  105. The primacy of the Apostolic See vindicated, by Francis Patrick Kenrick (Baltimore: J. Murphy, 1875). At Internet Archive and Open Library  (Digitizing sponsor: National Institute for Newman Studies, Book contributor: Saint Mary’s College of California)
  106. The principles of Christian apologetics: an exposition of the intellectual basis of the Christian religion, specially written for senior students , Thomas Joseph Walshe (London, New York [etc.] Longmans, Green and co, 1919). With Imprimatur. Available at Internet Archive and Open Library.
  107. The Question of Miracles, by George Hayward Joyce (B. Herder; Manresa Press, 1914). With Imprimatur. Available at Internet Archive.
  108. Quick Ten-Step Refutation of Sola Scriptura, by Dave Armstrong. Available in PDF, Kindle and EPUB formats at Internet Archive (Creative Commons license: Public Domain Mark 1.0) and may be read on Catholic Online. NB, The Internet Archive text appears to be compiled from essays by Dave Armstrong, beginning with this page, which were published at This Rock magazine.
  109. Rational religion, 2nd ed., by John Conway (Milwaukee: Hoffmann Brothers 1890). Available at Open Library and Internet Archive.
  110. Reasonableness of Catholic Ceremonies and Practices, by John J. Burke (New York: Benziger Brothers, 1909). With Imprimatur. Available on Project Gutenberg and in even more formats at Many Books.net.
  111. Religio Viatoris, 3rd edition, by Henry Edward Manning (London: Burns and Oates; New York: Catholic Publication Society, 1888). In English, The Religion of the Traveller. According to Cardinal Manning, it sets down, “in fewest words, the reasons for what I believe.” Available at Internet Archive and Open Library.
  112. A reply to the Rev. Dr. Turton’s “Roman Catholic doctrine of the Eucharist considered,” Philalethes Cantabrigiensis, the British critic, and the Church of England quarterly review, by Nicholas Patrick Wiseman (London: C. Dolman, 1839). Available at Internet Archive and Open Library (Digitizing sponsor: National Institute for Newman Studies, Book contributor: Saint Mary’s College of California).
  113. Revelation and Creeds, by J. M’Intyre, D.D (London, Edinburgh: Sands; St. Louis, Mo.: B. Herder 1907). With Imprimi Potest. Part of the Westminster Lectures (Third Series), edited by the Rev. Francis Aveling. Available in various formats at Internet Archive and Open Library.
  114. The Right to Life of the Unborn Child: a Controversy between Professor Hector Treub, M.D., Reverend R. van Oppenraay, D.D., S.J., Professor Th. M. Vlaming, M.D.: with an Appendix on a New Method of Operating, Ejecting the Fetus Alive, translated by C. Van der Donckt (New York: J. F. Wagner, 1903). Available on Open Library and Internet Archive (Digitizing sponsor: MSN; Book contributor: Robarts Library of Humanities & Social Sciences, University of Toronto). According to Open Library, it contains the following essays: “Medical abortion and the church”, by Hector Treub; “Reply to Prof. H. Treub,” by R. van Oppenraay; “Prof. H. Treub as penal legislator,” by Th. M. Vlaming; and “The right to life of the unborn child”, H. Treub; and “Narrowness or wholesome consistency,” by Th. M. Vlaming.
  115. Science and Religion: Lectures on the Reasonableness of Christianity and the Shallowness of Unbelief, by Most Rev. Roger Bede Vaughan (Baltimore: J.B. Piet, 1879). Available at Internet Archive and Open Library.
  116. The see of St. Peter, the rock of the church, the source of jurisdiction, and the centre of unity, by Thomas William Allies (London: Catholic Truth Society, 1896) Apologetics. Available at Internet Archive.
  117. Select treatises of St. Athanasius in controversy with the Arians, by Saint Athanasius, Patriarch of Alexandria, d. 373; John Henry Newman, 1801-1890 (London: Pickering, 1881). Available on Internet Archive and Open Library.
  118. Some Lies and Errors of History, by Reuben Parsons (Notre Dame, Ind., Office of the “Ave Maria”, 1893). Available at Internet Archive and Open Library [N.B.–This is a collection of articles refuting the various “Black Legends” used to calumniate Catholics: the civilization of Latin (Medieval) Europe, the Eastern schisms, the case of Galileo, the Inquisition, holy wars, St. Bartolomew’s Day, the career of Pope Alexander VI and Cardinal Richelieu, and “the man in the iron mask”.]
  119. Some Thoughts on Catholic Apologetics: A Plea for Interpretation, by Edward Ingram Watkin (Manresa Press, 1915). With Imprimatur. Available at Internet Archive.
  120. St. Peter at Rome: being an historical dissertation; with an appendix, containing reference to the discussion held in Rome, February 9th and 10th, 1872, in the Hall of the Pontificia Academia Tiberina, between three Catholic priests and three evangelical ministers, concerning the coming of St. Peter to Rome, by John Stewart M’Corry (London: Burns and Oates,1874). Available at Internet Archive and Open Library.
  121. The Superstition of Divorce, by G.K. Chesterton. Available at ManyBooks.net and at Internet Archive.
  122. Ten reasons proposed to his adversaries for disputation in the name of the faith and presented to the illustrious members of our universities, by Saint Edmund Campion. (St. Louis: B. Herder; London : Manresa Press, 1914). With Imprimatur. Translated from St. Edmund Campion’s Decem Rationes. Available at Internet Archive. [The Internet Archive index page also mentions Joseph Rickaby as an author.]
  123. To Tell You the Whole Truth about the Catholic Church and the Bible, by Fr. John Noone, Douglas McNair, Zachary Grimes, Richard Marchand, Rita Tucei, Ronald Young, Dorothy Ducote (1996, updated 2000, web version created 2001, PDF version created 2002). [N.B. This 80-page booklet provides “a bird’s eye view of the history of the Church and the Bible, with short answers to a few common questions.”] Available at the website of the Saint Charles Borromeo Catholic Church.
  124. The Theological Tractates and the Consolation of Philosophy, by Boethius, the Tractates translated by H.F. Stewart, D.D. and E.K. Rand, Ph.D. [who also wrote an excellent Introduction], and the Consolation translated in 1609 by “I.T.” and revised by H.F. Stewart (1918). Available at ManyBooks.net and Project Gutenberg. The Tractates included are: The Trinity is one God not three Gods; Whether Father, Son, and Holy Spirit may be substantially predicated of the Divinity; From the same to the same, how substances can be good in virtue of their existence without being absolute goods; On the Catholic Faith; A Treatise against Eutyches and Nestorius.
  125. Theotokos: or, The Divine Maternity, by John Stewart M’Corry, D.D.  (London: Burns and Oates, 1874). With Imprimatur. Available in various formats at Internet Archive and Open Library.
  126. The Tradition of the Syriac Church of Antioch, Concerning the Primacy and the Prerogatives of St. Peter and of his Successors the Roman Pontiffs, by the Most Rev. Cyril Benham Benni, Syriac Archbishop of Mossul (Nineveh), translated under the direction of the author by Joseph Gagliardi  (London: Burns, Oates, & Co., 1871). Available in various formats at Internet Archive and Open Library, with a second copy at Internet Archive and Open Library.
  127. A treatise on indulgences, by Jean Baptiste Bouvier, translated and with a preface by Rev. Frederick Oakeley (London : James Burns, 1848) Available in various formats at Open Library and, in fewer formats, at Internet Archive (Digitizing sponsor: National Institute for Newman Studies, Book contributor: Saint Mary’s College of California) [N.B., No Imprimatur, but quite orthodox]
  128. A Treatise on the Church, by Heinrich Klee, translated by Edward Cox (London: T. Jones, 1847). Available in various formats at Internet Archive and Open Library.
  129.  The true religion: being the grounds of the Catholic faith, by Ernest C. Messenger (Catholic Truth Society). Apologetics, Dogma. Available at Internet Archive (copyright status uncertain). (Digitizing sponsor: National Institute for Newman Studies, Book contributor: Saint Mary’s College of California). [NB, Uses 18th century spelling.]
  130. The Truths of the Catholic Religion Proved from Scripture Alone: in a Series of Popular Discourses Chiefly Addressed to Non-Catholics Volume 1, Fourth Edition, by Thomas Butler (London: T. Jones, 1857). Available at Internet Archive and Open Library.
  131. The Truths of the Catholic Religion Proved from Scripture Alone: in a Series of Popular Discourses Chiefly Addressed to Non-Catholics, Volume 2, Fourth Edition, by Thomas Butler (London: T. Jones, 1857). Available at Internet Archive.
  132. The Vatican Decrees in their Bearing on Civil Allegiance, by Henry Edward Manning (London: Longmans, Green, 1875). Available at Open Library and Internet Archive.
  133. What is the Catholic Church?, by Fr Stephen Wang. May be downloaded in PDF format through the Catholic Truth Society, which states that it provides “An introduction to the world’s oldest institution founded by Jesus Christ”.
  134. Where We Got the Bible: Our Debt to the Catholic Church, by the Right Rev. Henry G. Graham. With Imprimatur. May be read online at the Wayback Machine (7 September 2015 snapshot of Sean O Lachtnain’s Home Page) and at Catholic Apologetics Information. May be read online, and available in various formats (mobi, pdf, epub, etc.), at Internet Archive. [N.B., The copy archived from Sean O Lachtnain’s Home Page, now sadly defunct, is the best copy online. Please exercise prayerful caution on reading other texts on Catholic Apologetics Information, which appears to be run by a person/group with an irregular canonical relationship to the one true Church.]
  135. Which is the True Church?: or, a Few Plain Reasons for Joining the Roman Catholic Communion, by C.F.B. Allnatt (Edinburgh: Ballantyne Press, 1881). Available at Internet Archive. and Open Library.

For the complete list of free ebooks, visit the Catholic eBooks Project.

UPDATE (die XX Februarii A.D. MMXII): Please note that more apologetics texts have been added. See the List of Free eBooks (By Subject) of the Catholic eBooks Project.