Summa Theologica, or “theological summary,” was written by Thomas Aquinas in the 13th century and first published in 1485. It describes the relationship between God and man and man’s reconciliation with God. Aquinas writes as a philosopher intellectually interested in the pursuit of truth, but foremost he writes as a Catholic who is convinced that the salvation of humanity itself is at stake. (This SparkNotes guide discusses the first two parts of Summa Theologica, but not the third part or the Supplement that often accompanies it.)


Read the detailed three-section Summary & Analysis, a Full Work Summary, or a Full Work Analysis of Summa Theologica.

Core Ideas

Read descriptions of the main underlying ideas in Summa Theologica.

Further Study

Deepen your understanding of Summa Theologica by reading background information about Thomas Aquinas as well as about the historical and philosophical background for his work.