 In contrast to the meaning the word ‘sophism’ had in ancient philosophy, ‘sophisma’ in medieval philosophy is a technical term with no pejorative connotation: a sophisma proper is a sentence (proposition) that raises a difficulty for logic or grammar: it is a proposition whose truth value is difficult to determine, because it is ambiguous, puzzling or simply difficult to interpret, or a sentence that can be shown to be both grammatically correct and incorrect. Discussions of sophismata can be found in treatises of the twelfth century. Later they formed an important element of scholarly training in universities, featuring in different kinds of disputations: on a basic level the sophismata served to illustrate a theory, but they were also used to test the limits of a theory. The so-called sophismata-literature flourished during the thirteenth and fourteenth centuries; evidence of many important developments in logic and natural philosophy can be found in texts of this kind, where masters could feel free to investigate problems and develop their own views, much more than they could in more academic and strictly codified literary genres. In the wake of humanists’ opposition to the educational practices of traditional universities, the genre of sophismata disappeared in the early sixteenth century. 