See this online text:

See also the ebooks and texts listed on the page Philosophy and on the post “Online text: “Some Thomistic Reflections on the Foundations of Formal Logic”, by Joseph J. Sikora“, as well as these related ebooks and texts:

  • “Thomas Aquinas, Magister Ludi: The Relation of Medieval Logic and Theology”, by Prof. Joshua P. Hochschild, Ph.D., Hungarian Philosophical Review, Vol. 64, No. 4 (2020): pp. 43-62. Available in pdf format on this page of the Library of the Hungarian Academy of Sciences, on this page of PhilArchive, and on this page of PhilPapers.
  • Thoughts, Words and Things: An Introduction to Late Mediaeval Logic and Semantic Theory, by Prof. Paul Vincent Spade, Version 1.1: August 9, 2002 (Copyright @ 2002 by Paul Vincent Spade). 410 pages. Available in pdf format at Medieval Logic and Philosophy. (The text states: “Permission is hereby granted to copy this document in whole or in part for any purpose whatever, provided only that acknowledgment of copyright is given.”)
  • What Is Logic?, by Prof. Sara L. Uckelman, Ph.D., February 23, 2022. 355 pages. Available in pdf format at the webpage of Dr. Sara L. Uckelman.

On the secular observance of World Logic Day. For other texts and ebooks, you may access the List of Free eBooks (Arranged by Title), the List of Free eBooks (Grouped by Subject), the List of Worth-It Catholic Books & eBooks, and the main page of the Catholic eBooks Project.

“The courage to engage the whole breadth of reason, and not the denial of its grandeur – this is the programme with which a theology grounded in Biblical faith enters into the debates of our time… It is to this great logos, to this breadth of reason, that we invite our partners in the dialogue of cultures. To rediscover it constantly is the great task of the university.” (Pope Benedict XVI, Regensburg Lecture)