Contents

Data Source: Mmmonk

• Manuscript 501 contains four philosophical texts by Walter Burley (c. 1275-1344), an English cleric and logician. Following a political career under Edward II, he acquired a master's degree in theology and became a canon. At the request of others he translated works of Aristotle into English. The Tractatus de puritate artis logice (ff. 1r-69v) is his most important work, in which he presented a new position on the relationship between antecedent and consequent. The work exists in two version, of which this is the longer one (the Tractatus longior). The second and fourth text, called in the manuscript the Tractatus de accidentate qualitatum sensibilium et de ydemptitate specifica caloris celestis animalis et elementaris et de inductione subita forme substantialis et de unitate specifca contrariorum (ff. 70r-105v) and the Tractatus de causa intrinseca intensionis et remissionis formarum accidentalium (ff. 111r-158v), are two parts of a single work, known as the De formis accidentalibus. This work deals with the nature and ability of sensible forms. In between them is a small treatise called De contradictoriis (ff. 105r-111r). The manuscript dates from roughly halfway the fourteenth century, and is thus a contemporary text witness (Burley wrote these works in the 1320s). Possibly we can further precise the time of production; the last fly leaf holds a number of notes - created before it was used in this codex - including the repeated line 'Anno domini millesimo trecentesimo tricesimo sexto, die lune ante'. As Burley completed the Tractatus longior in 1328, the manuscript might therefore have been written in or at most a few years before 1336. The text is written in a single column and in a semi-textualis, showing a faster, less curated script with loops on some of the ascenders. Apart from decorated initials in penwork, the main decoration are red and blue paragraph marks. These have been added throughout the manuscript until fol 142, afterwards spaces have been left open for the initials and the paragraph marks lack. The binding consists of blind stamped leather over wooden boards. A fenestra is present on the back board. The codex was originally owned by the Ter Doest abbey, and found its way into the collection of Ten Duinen. The cross-shaped stamp of the latter abbey is found on the first and final leaves. [Summary by Dr. Mark Vermeer]