Aristotle's On interpretation (Peri hermeneias) was the subject of repeated commentary by medieval logicians. The work contains analysis of statement-making sentences, and it was, for most of Peter Abelard's lifetime, one of only two of Aristotle's numerous works which were generally available to Latin scholars. Glossing the work formed part of Abelard's teaching at Paris and elsewhere. He left brief word-by-word glosses from the period 1102–9 but wrote more substantial glosses during the second decade of the twelfth century, largely before he took up theology as well. The copies of what remains of his larger, more interpretive glosses, which are thought to have been written up c. 1118–20, when Abelard had become a monk at St Denis, and then revised and expanded during the 1120s and 1130s, are not of good quality. A text has to be reconstructed from three ‘almost shockingly different’ (p. lx) manuscripts which have been known for some time but not fully utilised in previous editions. The manuscripts present many uncertainties: by way of example the editors give a six-page list of confusing abbreviations – often just al. – that were used by the scribes for albus and animal, both words occurring frequently in examples of propositions. They give too a ten-page list of accidental transpositions of words, such transpositions being especially confusing when the structure of a proposition is at issue. There are also revisions and differences in arrangement, and at one point a break-out from the text to provide a small, separate work. The edition now published by Klaus Jacobi and Christian Strub is a formidable achievement. A detailed analysis of the contents of the Glosses is given in an extensive introduction which also fully represents the particular features (underlinings, paragraph markers, etc) of the manuscript texts. It is not uncommon for similar works to be found in twelfth-century scholastic manuscripts, and this volume is the first of two. Its companion, CCCM 206A, is in preparation by Jacobi and Strub, together with Peter King, and it will bring to light the text of a similar commentary on Interpretation which is seen to build upon Abelard's work and at times to dispute it. The volume will also contain all the indices. Apart from Abelard's brief early glosses, and a short fragment of a commentary which was printed by V. Cousin in 1836 by mistake, the Glosses edited here are the only published ones written in Latin from the period before 1150. For the most part they are not of a religious nature. But logic was one of the anvils upon which medieval theology was given shape, and propositions have religious applications. Abelard's Glosses at chapter ix contain discussion of providence and predestination, including discussion of ways to find a formula to resolve a ‘crafty quibble’ (‘illam callidam sed cauillatoriam … argumentationem’): granted that events can turn out otherwise, can God be mistaken?