 Scholastic usage of opinio probabilis conformed less to the rhetorical and more to the dialectical and methodological roles of endoxa (see also Section 4.1) – even if the opinions in question were applied in oratory and preaching. A scholastic author, in particular from the thirteenth century onward, who called a philosophical position or a theological claim probable alluded to an epistemic quality which justified serious consideration over and above a proposition’s suitability for inducing agreement in hearers. Sensory perception is sometimes mentioned as a basis for probable opinions which are held by all people (“Snow is  white”).[15]Apparently,  the opinions of the uneducated (rudes) and laymen (idiotae) did not qualify as probable, unless they were observation statements, for which uneducated people had as much competence as the educated. Competence in judging a matter was therefore the key to scholastic ascriptions of probability. The category of the “wisest” in medieval definitions of probability was a stand-in for “expert”, including top-ranking lawyers, theologians, medical doctors and philosophers – or even architects, engineers and other virtuosi of mechanical arts (as in Boethius’s definition of probable opinion). This expert status was acquired through training in a university or with a master. Moreover, an expert counted as such only in his field of  expertise.[16]  The sapientes to which the definition of probable opinion refers nevertheless had to possess at least some positive non-epistemic traits: they had to be decent (probus) and trustworthy people in order to possess weighty opinions. 