This book covers the years 1400 to 1557. In such a long period, we would expect great changes in the logic text-books used at Oxford and Cambridge. Indeed, there were great changes, but their timing is somewhat unexpected. If one considers just books written by Englishmen and copied or printed in England, then there is hardly any change at all between 1400 and 1530, the year in which the last surviving edition of the compilation text-book known as Libellus Sophistarum was printed. A period of fifteen years follows in which no surviving logic text was either written or printed, and then suddenly in 1545 we are confronted with the Dialectica of John Seton, a work which was to go through fourteen editions by the end of the sixteenth century, and which represents a completely different type of logic. In what follows, I shall focus on the fortuna of just one type of logic text in use between 1400 and 1530, namely the treatises devoted to obligationes, or the rules prescribing what one was obliged to accept and reject in a certain kind of logical disputation.

It is necessary first to consider the place of logic in the curriculum and the type of instruction which was offered, then to say something about fourteenth-century logicians and the obligationes texts used in the fifteenth century, and finally to examine the Libelli Sophistarum and other early printed texts in relation to fifteenth-century manuscript collections.