Abstract

Probability and Frequency. Aristotle frequently used the concept of probability, but apparently he did not make any persistent effort to clarify or analyze it. His description of a fortiori argument in The Topics, e.g., depends upon “the more or less likely or probable,” but he does not explore this notion. In The Rhetoric, where he applies himself to a puzzle about probability which the Sophists had advanced, he comes closer to an analysis of probability. Aristotle quotes Agathon, One might perchance say this was probable—That things improbable oft will hap to men, and elaborates thusly: “For what is improbable does happen [often], and therefore it is probable that improbable things will happen. Granted this, one might argue that ‘what is improbable is probable.’ “ Aristotle believes that one can avoid this imposture by distinguishing between “general” and “specific” probability, and apparently intends by the former the statistical sense of frequent occurrence; but he does not establish what he might mean by the probability of an individual event and so leaves the notion of “specific probability” unclear.