In ancient philosophy, there is no discipline called “logic” in the contemporary sense of “the study of formally valid arguments.” Rather, once a subfield of philosophy comes to be called “logic,” namely in Hellenistic philosophy, the field includes (among other things) epistemology, normative epistemology, philosophy of language, the theory of truth, and what we call logic today. This entry aims to examine ancient theorizing that makes contact with the contemporary conception. Thus, we will here emphasize the theories of the “syllogism” (...) in the Aristotelian and Stoic traditions. However, because the context in which these theories were developed and discussed were deeply epistemological in nature, we will also include references to the areas of epistemological theorizing that bear directly on theories of the syllogism, particularly concerning “demonstration.” Similarly, we will include literature that discusses the principles governing logic and the components that make up arguments, which are topics that might now fall under the headings of philosophy of logic or non-classical logic. This includes discussions of problems and paradoxes that connect to contemporary logic and which historically spurred developments of logical method. For example, there is great interest among ancient philosophers in the question of whether all statements have truth-values. Relevant themes here include future contingents, paradoxes of vagueness, and semantic paradoxes like the liar. We also include discussion of the paradoxes of the infinite for similar reasons, since solutions have introduced sophisticated tools of logical analysis and there are a range of related, modern philosophical concerns about the application of some logical principles in infinite domains. Our criterion excludes, however, many of the themes that Hellenistic philosophers consider part of logic, in particular, it excludes epistemology and metaphysical questions about truth. Ancient philosophers do not write treatises “On Logic,” where the topic would be what today counts as logic. Instead, arguments and theories that count as “logic” by our criterion are found in a wide range of texts. For the most part, our entry follows chronology, tracing ancient logic from its beginnings to Late Antiquity. However, some themes are discussed in several eras of ancient logic; ancient logicians engage closely with each other’s views. Accordingly, relevant publications address several authors and periods in conjunction. These contributions are listed in three thematic sections at the end of our entry. (shrink)

The first research report of the APDA project. Findings include that "gender is a significant predictor of type of placement (i.e. permanent versus temporary). The intercept tells us that the odds for male participants to have a permanent academic placement within the first two years after graduation are statistically significant at .37, p < 0.001 when year of graduation is held constant. The odds for female participants to have a permanent academic placement are 1.85, p < 0.001 when graduation year (...) is held constant. In terms of differences, the odds of having a permanent (versus temporary) academic placement are 85% greater for females as compared to males.". (shrink)

Academic Placement Data and Analysis (APDA), a project funded by the American Philosophical Association (APA) and headed by Carolyn Dicey Jennings (UC Merced), aims “to make information on academic job placement useful to prospective graduate students in philosophy.” The project has just been updated to include new data, which Professor Jennings describes in a post at New APPS. She also announces a new interactive data tool with which one can sift through and sort information. (from Daily Nous).

In the first book of the Prior Analytics, Aristotle sets out, for the first time in Greek philosophy, a logical system. It consists of a deductive system (I.4-22), meta-logical results (I.23-26), and a method for finding and giving deductions (I.27-29) that can apply in “any art or science whatsoever” (I.30). After this, Aristotle compares this method with Plato’s method of division, a procedure designed to find essences of natural kinds through systematic classification. This critical comparison in APr I.31 raises an (...) interpretive puzzle: how can Aristotle reasonably juxtapose two methods that differ so much in their aims and approach? What can be gained by doing so? Previous interpreters have failed to show how this comparison is legitimate or what important point Aristotle is making. The goal of this paper is to resolve the puzzle. In resolving this puzzle we not only learn more about the relationship be- tween division and the syllogistic in Aristotle. We will also learn something about the motivation for the syllogistic itself, by seeing the role that it plays in his philosophy of science. (shrink)

Sextus Empiricus was the voice of ancient Greek skepticism for posterity. His writings contain the most subtle and detailed versions of the ancient skeptical arguments known as Pyrrhonism, adding up to a distinctive philosophical approach. Instead of viewing philosophy as valuable because of the answers it gives to important questions, Sextus considered the search for answers itself to be fundamental and offered a philosophy centered on inquiry. Assuming the point of view of an active inquirer, Sextus developed arguments concerning conflicting (...) appearances, infinite regress in argument, dogmatic assertion of premises that are insufficiently justified, and many other ideas that fascinated later philosophers of knowledge across the centuries. He provided a unique perspective on topics of enduring relevance such as perception, language, logical consequence, belief, ignorance, disagreement, and induction. -/- While Sextus's importance to epistemology was appreciated by early modern and modern philosophers, he is underrepresented in contemporary discussions. In order to put Sextus back in the center of epistemology, these essays discuss his influence in the history of modern philosophy as well as contemporary engagements with Sextus's version of Pyrrhonian skepticism. The contributors investigate epistemology after Sextus, addressing four core themes of Sextus's skepticism: appearances and perception, the structure of justification and proof, belief and ignorance, and ethics and action. The arguments presented here bridge the divide between contemporary and ancient debates about knowledge and skepticism and will appeal to philosophers interested in epistemology and philosophy of mind as well as those interested in ancient philosophy and the history of philosophy more generally. (shrink)

This book, which originated as the author's 2013 Oxford dissertation, treats five modes of argument described by the Pyrrhonian skeptic Sextus Empiricus. In the first book of the Outlines of Pyrrhonism, Sextus claims that these modes bring about suspension of judgment, a mental state in which one finds the considerations for and against some claim to be balanced. We see the modes used both alone and in combination when Sextus investigates dogmatic philosophy. Accordingly, Sienkiewicz assigns a chapter to each mode (...) and concludes with how they might work together. This book has much to commend it: Sextus's text is clearly explained... (shrink)

How does Aristotle think about sentences like ‘Every x is y’ in the Prior Analytics? A recently popular answer conceives of these sentences as expressing a mereological relationship between x and y: the sentence is true just in case x is, in some sense, a part of y. I argue that the motivations for this interpretation have so far not been compelling. I provide a new justification for the mereological interpretation. First, I prove a very general algebraic soundness and completeness (...) result that unifies the most important soundness and completeness results to date. Then I argue that this result vindicates the mereological interpretation. In contrast to previous interpretations, this argument shows how Aristotle’s conception of predication in mereological terms can do important logical work. (shrink)

The aim of this paper is to show how PH II constitutes an original, ambitious, and unified skeptical inquiry into logic. My thesis is that Sextus’s argument in Book II is meant to accomplish both its stated goal (to investigate the topics typically grouped together by dogmatists under the heading of “logic”) and an unstated goal. The unstated goal is, in my view, interesting in itself and sheds new light on Sextus’s methodology. The goal is: to suspend judgement on the (...) effectiveness of dogmatic methodologies. (shrink)

The aim of this paper is to show how Outlines of Pyrrhonism II constitutes an original, ambitious, and unified skeptical inquiry into logic. My thesis is that Sextus’ argument in Book II is meant to accomplish both its stated goal and an unstated goal. The unstated goal is, in my view, interesting in itself and sheds new light on Sextus’ methodology. The goal is: to suspend judgement on the effectiveness of dogmatic methodologies.

Aristotle's syllogistic theory, as developed in his Prior Analytics, is often regarded as the birth of logic in Western philosophy. Over the past century, scholars have tried to identify important precursors to this theory. I argue that Platonic division, a method which aims to give accounts of essences of natural kinds by progressively narrowing down from a genus, influenced Aristotle's logical theory in a number of crucial respects. To see exactly how, I analyze the method of division as it was (...) originally conceived by Plato and received by Aristotle. I argue that, while Plato allowed that some divisions fail to rigorously investigate the essence, he began a program continued by Aristotle (and others in antiquity and the middle ages) of seeking norms for division that would apply in any domain whatsoever. This idea of a rigorous, general method was taken up and developed by Aristotle in his syllogistic. Aristotle also used Plato's conception of predication as parthood in his semantics for syllogistic propositions. As part of my argument, I prove that a semantics based on Platonic divisional structures is sound and complete for the deduction system used in the literature to model Aristotle's syllogistic. (shrink)

Review of Gail Fine, The Possibility of Inquiry (OUP 2014).