Traces of the dualist interpretation of good faith in the ius commune until the end of the sixteenth century

The dualist interpretation of good faith (bonafides) clearly distinguishes subjective good faith (guter Glaube, goede trouw) from objective good faith (good faith and fair dealing, Treu und Glauben, redelijkheid en billijkheid). The Roman jurists never contrasted these aspects. Even in the Middle Ages and in the early modern age the majority of jurists interpreted good faith in a monist manner. The dualist interpretation of good faith first appeared - in the form of a certain "protodualism" which was different from the modern dualist interpretation outlined above - probably in a work by Franciscus Aretinus in the second half of the fifteenth century. Modern dualism appeared in the first half of the sixteenth century in works of Medina and Rebuffus. Donellus' dualism was similar to Franciscus'protodualism. More than three centuries passed before modern dualism gained wide currency after the publication of Wächter's monograph in 1871. That is probably because the majority of humanists and subsequently also a number of pandectists had an aversion to classifications of a scholastic type lacking some firm source. Such caution favoured the monist or pluralist interpretation of good faith.