Summa Theologiae
The Summa Theologiae (also known as the Summa Theologica) is the best-known work of St. Thomas Aquinas (1225–1274), a scholastic theologian and Doctor of the Church. Written between 1265 and 1273, it is intended as a manual for beginners in theology and a compendium of all of the main theological teachings of the Catholic Church.
About This Edition
This digital edition is based on the English translation by the Fathers of the English Dominican Province, originally published in 1920. The text has been carefully extracted and formatted for modern web reading while preserving the original structure and content.
Structure of the Summa
The Summa Theologiae is divided into five main parts:
Part I (Prima Pars)
The Nature of God and Creation
Topics covered include:
- Sacred Doctrine
- The One God
- The Blessed Trinity
- Creation
- The Angels
- The Six Days of Creation
- Man
- The Government of Creatures
Part II-I (Prima Secundæ Partis)
Human Acts and Morality
Topics covered include:
- Man’s Last End
- Human Acts
- Passions
- Habits
- Vice and Sin
- Law
- Grace
Part II-II (Secunda Secundæ Partis)
The Virtues and Vices
Topics covered include:
- Faith, Hope, and Charity
- Prudence
- Justice
- Fortitude
- Temperance
- Acts Which Pertain to Certain Men
Part III (Tertia Pars)
Christ and the Sacraments
Topics covered include:
- The Incarnation
- The Life of Christ
- The Sacraments
- Baptism
- Confirmation
- The Holy Eucharist
- Penance
Supplement (Supplementum Tertiæ Partis)
Completion of the Sacraments and Last Things
Topics covered include:
- Penance (continued)
- Extreme Unction
- Holy Orders
- Matrimony
- The Resurrection
- Appendices
Search and Navigation
🔍 Search the Summa Theologiae - Find specific questions, topics, or theological concepts across all parts.
How to Use This Resource
Each question in the Summa follows a consistent structure:
- Question Title: The main topic being addressed
- Articles: Specific aspects of the question (usually 8-10 per question)
- Objections: Arguments against the position Aquinas will defend
- On the Contrary: Counter-arguments or authoritative statements
- I Answer That: Aquinas’s main response and reasoning
- Replies to Objections: Specific responses to each objection raised
Search and Navigation
- Use the search function to find specific topics or terms
- Navigate between questions using the Previous/Next buttons
- Return to this index at any time using the “Index” button
- Each part has its own index page for easier browsing
About St. Thomas Aquinas
St. Thomas Aquinas (1225-1274) was an Italian Dominican friar and Catholic priest who was an influential philosopher and theologian in the tradition of scholasticism. He is known for his synthesis of Aristotelian philosophy with Christian theology, and his works remain central to Catholic philosophical and theological study.
Study Resources
For deeper study of the Summa Theologiae, consider these approaches:
- Systematic Reading: Start with Part I and read through systematically
- Topical Study: Use the index to find questions on specific topics
- Comparative Study: Compare Aquinas’s positions with other theological works
- Historical Context: Study the medieval context in which Aquinas wrote
Copyright and Attribution
This text is based on the translation by the Fathers of the English Dominican Province, which is in the public domain. The original Latin text was written by St. Thomas Aquinas in the 13th century.
“The study of truth is in one way hard, in another easy. An indication of this is found in the fact that no one is able to attain the truth adequately, while, on the other hand, we do not collectively fail, but everyone says something true about the nature of things.” - St. Thomas Aquinas