Aeterni Patris, by Pope Leo XIII

St. Thomas Aquinas's Life and Works

• Saint Thomas Aquinas: A Biographical Study, by Fr. Placid Conway, O.P.
• Synopsis of the Theological Summa of St. Thomas Aquinas, by L.F. Kearney, O.P.
• On God and His Creatures, from Summa Contra Gentiles by St. Thomas Aquinas, ed. Rickaby

Scripture and Catholicism

• Catechism of the Summa Theologica of St. Thomas Aquinas, by Thomas Pègues, O.P.
• A Systematic Study of the Catholic Religion, by Rev. Charles Coppens, S.J.
• Westminster Lectures, ed. by Rev. Francis Aveling

History of Philosophy

• Aristotle and the Christian Church, by Brother Azarias
• History of Medieval Philosophy, by Maurice De Wulf
• St. Thomas Aquinas and Medieval Philosophy, by D.J. Kennedy, O.P.
• The Revival of Scholastic Philosophy in the Nineteenth Century, by Joseph Louis Perrier
• The Middles Ages: Sketches and Fragments (incomplete), by Thomas J. Shahan
• Handbook of the History of Philosophy, by Dr. Albert Stöckl
• History of Philosophy, by William Turner
• Scholasticism, by Joseph Rickaby, S.J.

Modernism

• Modernism and Modern Thought, by Fr. Bampton, S.J.
• Old Truths, Not Modernist Errors, by Rev. Norbert Jones, C.R.L.
• Modernism, by Cardinal Mercier
• St. Thomas and Modern Thought, by Edward A. Pace

Logic and Theories of Knowledge

• A Brief Text-Book of Logic and Mental Philosophy, by Rev. Charles Coppens, S.J.
• On Universals: An Exposition of Thomistic Doctrine, by Fr. Matteo Liberatore, S.J.
• The First Principles of Knowledge, by John Rickaby, S.J.
• The Knowableness of God. Its Relation to the Theory of Knowledge in St. Thomas, by Matthew Schumacher, C.S.C.
• Theories of Knowledge: Absolutism, Pragmatism, Realism, by Leslie J. Walker, S.J.

Natural Philosophy and Natural Theology

• Natural Theology, by Bernard Boedder, S.J.
• The Existence of God. A Dialogue, by Richard F. Clarke, S.J.
• The Physical System of St. Thomas, by Fr. Giovanni Maria Cornoldi, S.J.
• Psychology. Empirical and Rational, by Michael Maher, S.J.
• Classification of Desires in St. Thomas and in Modern Sociology, by Henry Ignatius Smith, O.P.

General Philosophy and Metaphysics

• Elementary Course of Christian Philosophy, by Br. Louis of Poissy
• The Metaphysics of the School, by Thomas Harper, S.J.
• General Metaphysics, by John Rickaby, S.J.

Ethics, Politics, Moral Theology

• A Brief Text-Book of Moral Philosophy, by Rev. Charles Coppens, S.J.
• Elements of Moral Theology, by John J. Elmendorf
• Catholic Moral Teaching and Its Antagonists, by Joseph Mausbach, D.D.
• Four-Square or The Cardinal Virtues, by Joseph Rickaby, S.J.
• Moral Philosophy: Ethics, Deontology and Natural Law, by Joseph Rickaby, S.J.
• The State and the Church, by John A. Ryan, D.D., LL.D.
• A Short History of Moral Theology, by Rev. Thomas Slater, S.J.