Written in political exile during the Second World War and first published in 1945, Karl Popper's _The Open Society and Its Enemies_ is one of the most influential books of the twentieth century. Hailed by Bertrand Russell as a 'vigorous and profound defence of democracy', its now legendary attack on the philosophies of Plato, Hegel and Marx exposed the dangers inherent in centrally planned political systems. Popper's highly accessible style, his erudite and lucid explanations of the thought of great philosophers (...) and the recent resurgence of totalitarian regimes around the world are just three of the reasons for the enduring popularity of_The Open Society and Its Enemies_, and for why it demands to be read both today and in years to come. This is the first of two volumes of _The Open Society and Its Enemies_. (shrink)

In this volume, John Horty brings to bear his work in logic to present a framework that allows for answers to key questions about reasons and reasoning, namely: What are reasons, and how do they support actions or conclusions?

The purpose of this essay is to both discuss commands as a species of speech act and to discuss commands within the broader framework of how they are used and ...

This introduction to the basic forms of deductive inference as evaluated by methods of modern symbolic logic is de­signed for sophomore-junior-level stu­dents ready to specialize in the study of deductive logic. It can be used also for an introductory logic course. The inde­pendence of many sections allows the instructor utmost flexibility. The text consists of eight chapters, the first six of which are designed to intro­duce the student to basic topics of sen­tence and predicate logic. The last two chapters extend (...) the procedures of the first six to alethic modal logic, the logic of imperatives, and deontic logic. Throughout the text there is an attempt to relate symbolic techniques to issues in the philosophy of logic. (shrink)

Recently it has become almost the received wisdom in certain quarters that Kripke models are appropriate only for something like metaphysical modalities, and not for logical modalities. Here the line of thought leading to Kripke models, and reasons why they are no less appropriate for logical than for other modalities, are explained. It is also indicated where the fallacy in the argument leading to the contrary conclusion lies. The lessons learned are then applied to the question of the status of (...) the formula. (shrink)

The goal of this paper is to frame a theory of reasons--what they are, how they support actions or conclusions--using the tools of default logic. After sketching the basic account of reasons as provided by defaults, I show how it can be elaborated to deal with two more complicated issues: first, situations in which the priority relation among defaults, and so reasons as well, is itself established through default reasoning; second, the treatment of undercutting defeat and exclusionary reasons. Finally, and (...) by way of application, I show how the resulting account can shed some light on Jonathan Dancy's argument from reason holism to a form of extreme particularism in moral theory. (shrink)