 Pre-modern notions of probability were very different. No pre-modern notion of probability was numerical. A calculus of probabilities simply did not exist before the seventeenth  century.[2]  Pre-modern probability was a qualitative predicate mainly applied to propositions (e.g., by calling an opinion probable), but extending to other subject matters as well. The use of the word ‘probable’ in ordinary language still resembles this older usage to some extent (Franklin 2001, 126; Hacking 2006, 18). Yet, whereas the mathematics of probability was invented in the early modern era, some continuities in the meaning(s) of probability exist. These continuities will be discussed in Section 6. Until that point, it is best to forget the connotations of modern notions of probability and to approach medieval probability-related terms without modern preconceptions. For their vocabulary, medieval and Renaissance authors could draw on a well-stocked ancient Greek and Roman store of probability-related terms. In consequence, a variety of Latin terms were in use, which are today translated as ‘probable’, ‘plausible’, ‘reputable’ (probabilis); ‘truth-like’, ‘apparently true’ (verisimilis); ‘credible’, ‘worthy of belief’ (credibilis, opinabilis); or ‘most often’, ‘frequently’ (ut frequenter). Modern readers may not always find it obvious that these terms relate to probability; but, in fact, they are highly relevant for its conceptual evolution. Up to the nineteenth century, when philosophers spoke about probability their claims were still often rooted in medieval notions of probability.