On the Tract De Defectibus in Missa Occurrentibus Part 1: A Possible Dominican Source for the Post-Tridentine Reform?

ABSTRACT: While Johann Burchard’s Ordo Missae is recognized as an important source for the post-Tridentine liturgical commission, identifying other sources for the 1570 Roman Missal remains difficult. In a two-part series, I propose that a late fifteenth-century tract entitled De defectibus in missa occur-rentibus , widely distributed as incunabula from 1475 onward, is a major source for the De defectibus tract found in the Missal of Pius V. In this first essay, the incunabula tract is edited and translated into English to promote further study on this source. Its Dominican sources, especially Thomas Aquinas, are given special attention in view of the second essay in this series, which will demonstrate the dependence of the 1570 Missal on Thomas’s Eucharistic doctrine.