Presenting the first book-length study in English of Aristotle's Sophistical Refutations, this work takes a fresh look at this seminal text on false reasoning.

The article examines Aristotle’s seminal discussion of the fallacy of begging the question, reconstructing its complex articulation within a variety of different, but related, contexts. I suggest that close analysis of Aristotle’s understanding of the fallacy should prompt critical reconsideration of the scope and articulation of the fallacy in modern discussions and usages, suggesting how begging the question should be distinguished from a number of only partially related argumentative faults.

The logician's central concern is with the validity of argument. A logical theory ought, therefore, to provide a general criterion of validity. This book sets out to find such a criterion, and to describe the philosophical basis and the formal theory of a logic in which the premises of a valid argument are relevant to its conclusion. The notion of relevance required for this theory is obtained by an analysis of the grounds for asserting a formula in a proof.

Just as Aristotelian dialectic sharply distinguishes between real and fallacious arguments, Aristotelian rhetoric distinguishes between real and fallacious enthymemes. For this reason Aristotle’s Rhetoric includes a chapter – chapter II.24 – that is exclusively devoted to what Aristotle calls “topoi” of fallacious enthymemes. Thus, the purpose of this chapter seems to be equivalent to the purpose of the treatise Sophistici Elenchi, which attempts to give a complete list of all possible types of fallacious arguments. It turns out that, although the (...) Rhetoric’s list of fallacious types of rhetorical arguments basically resembles the list from the Sophistici Elenchi, there also are some striking differences. The paper tries to account for the relation between these two, more or less independent, Aristotelian approaches to the phenomenon of fallacious arguments. Can one of these two lists be seen as the basic or original one? And what is the point in deviating from this basic list? Are all deviations occasioned by the specific contexts of the rhetorical use on the one hand, and the dialectical on the other? Or do the two lists display different logical assumptions? Even an only tentative answer to this set of questions will help to clarify another but closely related scholarly problem, namely the relation between the Rhetoric’s list of topoi for real enthymemes and the Topics’ list of topoi for real dialectical arguments. It will also help to account for the general place of fallacious arguments within Aristotle’s dialectic-based approach the rhetoric. (shrink)

I discuss paradoxes of implication in the setting of a proof-conditional theory of meaning for logical constants. I argue that a proper logic of implication should be not only relevant, but also constructive and nonmonotonic. This leads me to select as a plausible candidate LL, a fragment of linear logic that differs from R in that it rejects both contraction and distribution.

In the Posterior Analytics (I 6, 75a18–27) Aristotle discusses a puzzle which endangers the possibility of inferring a non-necessary conclusion. His solution relies on the distinction between the necessity of the conclusion's being the case and the necessity of admitting the conclusion once one has admitted the premisses. The former is a factual necessity, whereas the latter is meant to be a normative or deontic necessity that is independent of the facts stated by the premisses and the conclusion. This paper (...) maintains that Aristotle resorts to this distinction because he thinks that, as long as it is conceived as a factual relation, logical consequence cannot exist independently of the facts expressed by the premisses and the conclusion. As a corollary, the necessity of such a consequence relation always requires the necessity of these facts. Aristotle holds this factual conception of logical consequence responsible for the puzzle, since it cannot account for valid syllogisms with contingent or false premisses. The alternative conception of necessity is then introduced by him in order to make good this deficiency. The distinction between the necessity of being and the necessity of saying was revived by the Oxford logician E. W. B. Joseph, and taken over by Frank Ramsey in his seminal Truth and Probability, but has not received attention from recent interpreters of Aristotle's logic. This paper, however, argues that, in spite of its intrinsic interest, the distinction bore no significant fruit in Aristotle's logical doctrine. (shrink)

In this radical reinterpretation of Aristotle's Metaphysics, Walter E. Wehrle demonstrates that developmental theories of Aristotle are based on a faulty assumption: that the fifth chapter of Categories is an early theory of metaphysics that Aristotle later abandoned.

ABSTRACT: English translation of the 2nd/3rd century Peripatetic Philosopher's Alexander of Aphrodisias commentary on Aristotle's non-modal syllogistic, i.e. on one of the most influential logical texts of all times. -/- Volume includes introduction on Alexander of Aphrodisias and the early commentators, translation with notes and comments, appendices with a new translation of Aristotle's text, a summary of Aristotle's non-modal syllogistic and textual notes.

This work provides some interesting new results on the notion of the topos and the theory of hypothetical syllogisms in Aristotle based on an incisive interpretation of Aristotle's _Topics_ and certain passages of the _Analytics_.

Aristotle was the first and one of the greatest logicians. He not only devised the first system of formal logic, but also raised many fundamental problems in the philosophy of logic. In this book, Dr Lear shows how Aristotle's discussion of logical consequence, validity and proof can contribute to contemporary debates in the philosophy of logic. No background knowledge of Aristotle is assumed.

What are people who disagree about logic disagreeing about? The paper argues that (in a wide range of cases) they are primarily disagreeing about how to regulate their degrees of belief. An analogy is drawn between beliefs about validity and beliefs about chance: both sorts of belief serve primarily to regulate degrees of belief about other matters, but in both cases the concepts have a kind of objectivity nonetheless.