Sixtus of Siena’s annotations constantly cite one another. “See Annotation 233 of the fifth book,” he writes, and a diligent reader of the sixteenth century would mark the place, fetch the other volume, and count his way to the right column. In this library those citations are links — several hundred of them — and making them clickable exposed something the print’s first readers could only stumble over silently: sometimes the number is wrong, and has been wrong since the compositor set the type.

Three such errors surfaced as this edition was built.

Thamar: “113” for 114

In Annotation II of the New Testament annotations, on Thamar in the genealogy of Our Lord, Sixtus writes that Chrysostom “accuses Thamar as a harlot — whom elsewhere he defends from the charge of fornication,” and sends the reader to Annotation 113 of the fifth book. But Annotation 113 concerns Joseph’s brothers and their accusation (Genesis 37). The annotation that actually treats her case is the very next one: Annotation 114, Whether Tamar, in lying with Judah, perpetrated a crime (Genesis 38:16). A reader of the citation’s words — not merely its number — finds the mistake at once; the number simply came off the press one short.

The star of Bethlehem: “107” for 108

In the annotation on whether the stars are ensouled, Sixtus quotes Origen on the star that appeared in the East — “either like the other stars, or perhaps even more excellent” — and directs us to Annotation 107 of the preceding book. That annotation asks whether it is lawful for a good man to lie: plainly not the place. One annotation later stands Annotation 108, Whether the stars are rational living beings, as Philo and Origen held — the exact question, treating the exact author. Again the press fell one short.

Arnobius and the Virgin: “153” for 156

In Annotation CXXXVI, on Our Lady’s purification, Sixtus reports that “Arnobius, in the exposition of Psalm 14, seems to attribute certain stains to Mary, from which, on Christ’s entering into her womb, she was cleansed,” and cites Annotation 153 of book 5 — which concerns the invocation of the saints. The true target identifies itself beyond argument: Annotation 156, In what manner the Blessed Virgin was sanctified by the entrance of Christ stands upon Psalm 14 itself — the very exposition of Arnobius the citation names.

How the mending is done

In each case the citation in this edition has been emended to the true number, and a bracketed note left in the text recording what the print actually reads — “[the print gives ‘113’, an error of the press: the Thamar annotation is the 114th]” — so that the correction is visible, never silent. The links, the indexes, and the combined PDF edition all follow the emended numbers.

The same press left other fingerprints. One annotation went out numbered only ”✚ ✚” — two cross-marks where the numeral should stand, a compositor’s lapse between CXXVI and CXXVII — and is carried in this edition as the unnumbered annotation. Another was printed “ANNOTATIO LXXIX” though the sequence demands CLXXIX — a dropped C, quietly supplied.

For four and a half centuries these small errors were frozen in every copy of the Bibliotheca Sancta in every library that holds one. A printed book cannot mend itself. A living edition can — provided it shows its work.