 Endoxa were important for ancient rhetoric and dialectic. Rhetoric aims at persuasion, and opinions which are generally accepted or backed up by the intellectual reputation of their sources tend to be persuasive. In rhetorical usage, therefore, endoxon and probabilis can be equated to a proposition with “expected persuasiveness”. Dialectic is concerned with disputes and inquiry through the exchange of arguments. Endoxa, in ancient dialectic, were starting, intermediate, and often also endpoints of such activities; and, to this extent, they might be seen as instruments for intellectual training. This, however, would create the wrong impression of the overall role of endoxa in Aristotle’s methodology of the sciences (Haskins 2004; Kraut 2006; Renon 1998). He also takes them to be reasonable starting points for scientific inquiry, as well as material for testing its results. The process of inquiry should select the right endoxa and order them systematically. In this respect, the connection between likely truth and being held true by many or wise people is presumed by Aristotle. There is no guarantee, however, that an endoxon is true, which makes it an apt object of inquiry.