In this paper, I examine Cicero’s oft-neglected De Divinatione, a dialogue investigating the legitimacy of the practice of divination. First, I offer a novel analysis of the main arguments for divination given by Quintus, highlighting the fact that he employs two logically distinct argument forms. Next, I turn to the first of the main arguments against divination given by Marcus. Here I show, with the help of modern probabilistic tools, that Marcus’ skeptical response is far from the decisive, proto-naturalistic assault (...) on superstition that it is sometimes portrayed to be. Then, I offer an extended analysis of the second of the main arguments against divination given by Marcus. Inspired by Marcus’ second main argument, I formulate, explicate, and defend a substantive principle of scientific methodology that I call the “Ciceronian Causal-Nomological Requirement” (CCR). Roughly, this principle states that causal knowledge is essential for relying on correlations in predictive inference. Although I go on to argue that Marcus’ application of the CCR in his debate with Quintus is dialectically inadequate, I conclude that De Divinatione deserves its place in Cicero’s philosophical corpus, and that ultimately, its significance for the history and philosophy of science ought to be recognized. (shrink)

Seventeenth-century “chance combinatorics” was a self-contained theory. It had an objective notion of chance derived from physical devices with chance properties, such as casts of dice, combinatorics to count chances and, to interpret their significance, a rule for converting these counts into fair wagers. It lacked a notion of chance as a measure of belief, a precise way to connect chance counts with frequencies and a way to compare chances across different games. These omissions were not needed for the theory’s (...) interpretation of chance counts: determining which are fair wagers. The theory provided a model for how indefinitenesses could be treated with mathematical precision in a special case and stimulated efforts to seek a broader theory. (shrink)

Leibniz uses the concept of probability in both epistemic and non-epistemic contexts, as do many of his contemporaries. Some commentators have claimed that this dual-use is inexact or confused. In this paper, I describe Leibniz’s understanding of the concept of probability and discuss its dual usage in his work. Then, building on Leibniz’s creation theory, in conjunction with Russell’s interpretation of the Principle of Sufficient Reason, I endeavor to justify this dual usage and to show that this justification is also (...) valuable for the contemporary discussion of the concept of probability. Published on 2022-12-28 10:04:03. (shrink)

ABSTRACT The sections devoted to dissociation in The New Rhetoric identify many verbal forms that can express this reconceptualizing line of argument. This article reviews the linguistic options offered in English for epitomizing dissociations, including tautologies and constructions that prompt diverging meanings, orthographical devices like capitalization or subscripts that produce variants of a single word, word schemes like agnominatio and polyptoton that alter core forms, and affixes or modifiers that are either available as antonyms or require forcing apart by subsequent (...) antitheses. Paying attention to the verbal expression of dissociations highlights cases that may or may not qualify as the rich reconceptualizations Perelman and Olbrechts-Tyteca had in mind. Arguments that involve three distinguished terms may, for example, reach a limit where dissociations merge into arguments from division, a long recognized device in traditional rhetoric/dialectic. (shrink)