Book excerpt: A new translation of Philipp Melanchthon's Loci Communes into American English directly from the original Latin text. Bilingual edition with the original Latin manuscript in the back. This edition also contains a new 2023 Afterword by the Translator. Loci Communes is the first systematic formulation of Protestant theology and a foundational text of multiple denominations, particularly Lutheranism. This also deeply influenced the Reformed tradition as Melanchthon’s pupil Zacharias Ursinus was the main author of the Heidelberg Catechism. In Melanchthon's own words, it is about “the proper dogmas of the Church about God, about eternal things, about the Law of God, about Sin, about the Gospel, about Grace, Justice, and the Sacraments, and later also the doctrine about civil life.” This Systematic Theology was first published in 1521 in New Latin, which was proofread by Luther and published the same year. Luther never wrote a systematic theology because he considered the Loci Communes to be a sufficient summary of Evangelical doctrine. He wrote "next to Holy Scripture, there is no better book" and at one point he talked about adding it to his Biblical canon: "We possess no work wherein the whole body of theology, wherein religion, is more completely summed up, than in Melanchthon's Common-place Book; all the Fathers, all the compilers of sentences, put together, are not to be compared with this book. It is, after the Scriptures, the most perfect of works. Melancthon is a better logician than myself; he argues better. My superiority lies rather in a rhetorical way. If the printers would take my advice, they would print those of my books which set forth doctrine,—as my commentaries on Deuteronomy, on Galatians, and the sermons on the four books of St John. My other writings scarcely serve a better purpose than to mark the progress of the revelation of the gospel."