The art of doubting in Obligationes Parisienses Sara L. Uckelman, Jaap Maat, Katherina Rybalko Abstract: Recent studies on obligationes tend to focus on the specific type of positio. This emphasis has led to a neglect of the less standard types, including dubitatio. While some claim that dubitatio is merely a trivial variant of positio, we show that the dubitatio rules given in the 13th-century treatise Obligationes Parisienses are by no means trivial and in fact lend themselves to a somewhat peculiar system of dialogue. Dubitatio in this treatise shares many aspects with dubitatio in two other 13th-century treatises, by William of Sherwood and Nicholas of Paris. We use these similarities to shed some light on the history of dubitatio in general and the interpretation of the Parisienses rules in particular.