Combines selected philosophical passages from Thomas' "Summa Theologica" with detailed footnotes and explanations for modern readers.

When Leo XIII promulgated Aeterni Patris in 1879, he stipulated that the "Leonine," or official, edition of the Summa should always be printed in conjunction with Cajetan's Commentary. For five hundred years they were studied together. Generations were trained by reading through the Summa article by article with Cajetan's commentaries in hand. Early printed editions of the Summa typically included them in a Talmudic arrangement, as marginal text running around each article by Aquinas. This edition imitates that example. Recently, serious thinkers of all denominations-and none-have found new reasons to be interested in St. Thomas. His text is deceptively simple, yet important issues are handled in every article, sometimes below the surface. Cajetan extracts these hidden issues, and explains and elaborates on them with remarkable affinity to modern analytical philosophy. Part of that affinity lies in the use of modal logic, a tool whose importance was overlooked between the Renaissance and the twentieth century. The time is ripe for an analytically-inspired translation of Thomas: hence this volume. Never until now has Cajetan's Commentary been put into English in its entirety. William Marshner's translation is consistent with fidelity to the technical force of the original. The translator's footnotes acknowledge what empirical science has made obsolete in the work of St. Thomas, and also make clear how much today's science would have saved Thomas useless labor. This volume will, for the first time, make Cajetan's help available to the modern reader.

The Summa Theologica is a compendium of theology written by Thomas Aquinas between 1265 and 1273. In Roman Catholicism it is the sum of all known learning and doctrine, of all that can be known about God and humanity's relations with God -- a landmark in the history of theology that famously offers five proofs of God's existence, the first three of which are cosmological arguments; the fourth, a moral argument; and the fifth, a teleological argument. The third quarter of the thirteenth century marked the first decisive philosophical encounter between Hellenism and Christianity. The rediscovery of Aristotle's works after the Dark Ages ushered in a new era of intellectual fervor in Europe, and the work of Thomas Aquinas is a commentary on Aristotle, whose writings were lost to the non-Arabic world until the beginning of the Thirteenth Century. To many, Aristotle's worldview was a pagan threat to Christianity. To Aquinas, it provided an exciting cosmological framework on which to build an all-encompassing Christian worldview. His thoughts unfolding with a calmness of order and an assurance of judgment, Aquinas explores in the Summa the primary role of the senses in the acquisition of knowledge and the metaphysical analysis of things in terms of matter and form. But unlike Aristotle's "God," who did not care one whit about the world, the God of Christianity, insisted Aquinas, is a personal God. Like Aristotle, Aquinas believed that each human being has a soul and that all created things have a purpose. For Christians, all are part of a divine plan. This dazzling synthesis of Catholic doctrine has had a profound impact on Christian thinking since the thirteenth century and has become the de facto official teaching of the Catholic Church -- the intellectual underpinning of the Church to this day.

Nevertheless, if you read this short book and understand what it lays out, you will be in the top 0.001% of people in the world who have a working knowledge of the philosophy and theology of Saint Thomas Aquinas. You will have the knowledge to pass a class called “Thomas Aquinas 101,” and you will be ready to study Thomas Aquinas at the collegiate level. You will have the building blocks to move forward. At the end of this book, I make practical recommendations to take it to the next level and recommend the next books to read.

Thomas Aquinas offers teleological systematisation of the habits needed for human flourishing. His metaphysical jurisprudence remodels ethics upon this, rather than on a moral precept. “Eternal law” governing the world determines “natural law”, reflected in human legislation (a variety of the “anthropic principle”). Finally, law, unwritten, is infused spirit as self-consciousness, “universal of universals”. Acquired virtues elicit this, become effusion, represented in religion as gifts or graces. But mind’s or spirit’s omnipresence, necessarily “closer to me than I am to myself”, supersedes the abstractions of heteronomy versus autonomy. The habitual well-being brought by prudence, justice, courage and temperance prompts this picture of gifts and graces. The “theological virtues”, faith (explicit or implicit) and hope fulfilled in love, “crown” our natural rationality, set toward as being the universal. “Become what you are”. Heteronomous law is thus “defused” at root by grounding it entirely upon immovable spiritual (mental) inclination towards universal fulfilment as naturally desired, reflection shows. Virtue, finally, is best assessed as a capacity for the individually beautiful yet habit-based action, Aristotle’s to kalon. Aquinas puts this picture as summed up in the beatitudes of the “Sermon on the Mount”.