 The genre of “proprietates  terminorum” developed in the twelfth century alongside the reception of Aristotle’s Sophistical refutations, and the logico-semantical analysis of fallacies seems to have been one of its primary  applications.[13]  It is an umbrella genre for, among others, theories of meaning and reference, the use-mention distinction, quantification, and tense. These are utilized in several of Heytesbury’s works with terminological variations. Three of these issues will be presented here: the theories of “suppositio”, “mobilitatio”, and “ampliatio”.