Although the study of reasons plays an important role in both epistemology and moral philosophy, little attention has been devoted to the question of how, exactly, reasons interact to support the actions or conclusions they do. In this book, John F. Horty attempts to answer this question by providing a precise, concrete account of reasons and their interaction, based on the logic of default reasoning. The book begins with an intuitive, accessible introduction to default logic itself, and then (...) argues that this logic can be adapted to serve as a foundation for a concrete theory of reasons. Horty then shows that the resulting theory helps to explain how the interplay among reasons can determine what we ought to do by developing two different deontic logics, capturing two different intuitions about moral conflicts.In the central part of the book, Horty elaborates the basic theory to account for reasoning about the strength of our own reasons, and also about the related concepts of undercutting defeaters and exclusionary reasons. The theory is illustrated with an application to particularist arguments concerning the role of principles in moral theory. The book concludes by introducing a pair of issues new to the philosophical literature: the problem of determining the epistemic status of conclusions supported by separate but conflicting reasons, and the problem of drawing conclusions from sets of reasons that can vary arbitrarily in strength, or importance. (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?

Let us say that a normative conflict is a situation in which an agent ought to perform an action A, and also ought to perform an action B, but in which it is impossible for the agent to perform both A and B. Not all normative conflicts are moral conflicts, of course. It may be that the agent ought to perform the action A for reasons of personal generosity, but ought to perform the action B for reasons of prudence: perhaps (...) A involves buying a lavish gift for a friend, while B involves depositing a certain amount of money in the bank. In general, our practical deliberation is shaped by a concern with a variety of morally neutral goods—not just generosity and prudence, but any number of others, such as etiquette, aesthetics, fun—many of which are capable of providing conflicting reasons for action. I mention these ancillary values in the present setting, however, only to put them aside. We will be concerned here, not with normative conflicts more generally, but precisely with moral conflicts—situations in which, even when our attention is restricted entirely to moral reasons for action, it is nevertheless true that an agent ought to do A and ought to do B, where it is impossible to do both. (shrink)

inheritance reasoning in semantic networks allowing for multiple inheritance with exceptions. The approach leads to a definition of iaheritance that is..

This paper describes one way in which a precise reason model of precedent could be developed, based on the general idea that courts are constrained to reach a decision that is consistent with the assessment of the balance of reasons made in relevant earlier decisions. The account provided here has the additional advantage of showing how this reason model can be reconciled with the traditional idea that precedential constraint involves rules, as long as these rules are taken to be defeasible. (...) The account presented is firmly based on a body of work that has emerged in AI and Law. This work is discussed, and there is a particular discussion of approaches based on theory construction, and how that work relates to the model described in this paper. (shrink)

The doctrine of precedent, as it has evolved within the common law, has at its heart a form of reasoning—broadly speaking, alogic—according to which the decisions of earlier courts in particular cases somehow generalize to constrain the decisions of later courts facing different cases, while still allowing these later courts a degree of freedom in responding to fresh circumstances. Although the techniques for arguing on the basis of precedent are taught early on in law schools, mastered with relative ease, and (...) applied on a daily basis by legal practitioners, it has proved to be considerably more difficult to arrive at a theoretical understanding of the doctrine itself—a clear articulation of the underlying logic. (shrink)

From a philosophical standpoint, the work presented here is based on van Fraassen [26]. The bulk of that paper is organized around a series of arguments against the assumption, built into standard deontic logic, that moral dilemmas are impossible; and van Fraassen only briefly sketches his alternative approach. His paper ends with the conclusion that “the problem of possibly irresolvable moral conflict reveals serious flaws in the philosophical and semantic foundations of ‘orthodox’ deontic logic, but also suggests a rich set (...) of new problems and methods for such logic.” My goal has been to suggest that some of these methods might be found in current research on nonmonotonic reasoning, and that some of the problems may have been confronted there as well.I have shown that nonmonotonic logics provide a natural framework for reasoning about moral dilemmas, perhaps even more useful than the ordinary modal framework, and that the issues surrounding the treatment of exceptional information within these logics run parallel to some of the problems posed by conditional oughts. However, there is also another way in which deontic logic might benefit from a connection to nonmonotonic reasoning. A familiar criticism among ethicists of work in deontic logic is that it is too abstract, and too far removed from the kind of problems confronted by real agents in moral deliberation. It must be said that similar criticisms of abstraction and irrelevance are often lodged against work in nonmonotonic reasoning by more practically minded researchers in artificial intelligence; but here, at least, the criticisms are taken seriously. Nonmonotonic logic aims at a qualitative account of commonsense reasoning, which can be used to relate planning and action to defeasible goals and beliefs; and at least some of the theories developed in this area have been tested in realistic situations. By linking the subject of deontic logic to this research, it may be possible also to relate the idealized study of moral reasoning typical of the field to a more robust treatment of practical deliberation. (shrink)

The purpose of this paper is to explore a new deontic operator for representing what an agent ought to do; the operator is cast against the background of a modal treatment of action developed by Nuel Belnap and Michael Perloff, which itself relies on Arthur Prior's indeterministic tense logic. The analysis developed here of what an agent ought to do is based on a dominance ordering adapted from the decision theoretic study of choice under uncertainty to the present account of (...) action. It is shown that this analysis gives rise to a normal deontic operator, and that the result is superior to an analysis that identifies what an agent ought to do with what it ought to be that the agent does. (shrink)

The result model of precedent holds that a legal precedent controls a fortiori cases—those cases, that is, that are at least as strong for the winning side of the precedent as the precedent case itself. This paper defends the result model against some objections by Larry Alexander, drawing on ideas from the field of Artificial Intelligence and Law in order to define an appropriate strength ordering for cases.

Early attempts at combining multiple inheritance with nonmonotonic reasoning were based on straightforward extensions of tree-structured inheritance systems, and were theoretically unsound. In The Mathcmat~'cs of Inheritance Systcrns, or TMOIS, Touretzky described two problems these systems cannot handle: reasoning in the presence of true but redundant assertions, and coping with ambiguity. TMOIS provided a definition and analysis of a theoretically sound multiple inheritance system, accom-.

This paper points out some problems with two recent logical systems – one due to Prakken and Sartor, the other due to Kowalski and Toni – designedfor the representation of defeasible arguments in general, but with a specialemphasis on legal reasoning.

The purpose of this paper is to e»tahlish some connections between precedent-based reasoning as it is studied in the field of Artificial Intelligence and Law, particularly in the work of Ashley, and two other fields: deontic logic and nonmonotonic logic. First, a deontic logic is described that allows lor sensible reasoning in the presence of conflicting norms. Second, a simplified version of Ashley's account of precedent-based reasoning is reformulated within the framework of this deontic logic. Finally, some ideas from the (...) theory of nonmonotonic inheritance are employed to show how Ashley's account might be elaborated to allow for a richer representation of the process of argumentation. (shrink)

This paper contributes to the foundations of a theory of rational choice for artificial agents in dynamic environments. Our work is developed within a theoretical framework, originally due to Bratman, that models resource-bounded agents as operating against the background of some current set of intentions, which helps to frame their subsequent reasoning. In contrast to the standard theory of rational choice, where options are evaluated in isolation, we therefore provide an analysis of situations in which the options presented to an (...) agent are evaluated against a background context provided by the agent’s current plans—commitments to future activities, which may themselves be only partially specified. The interactions between the new options and the background context can complicate the task of evaluating the option, rendering it either more or less desirable in context than it would have been in isolation.  2001 Elsevier Science B.V. All rights reserved. (shrink)

The goal of a logic is to define a consequence relation between a set of formulas Γ and, in most cases, an individual formula A. This definition generally takes one of two forms. From a proof theoretic standpoint, A is said to be a consequence of Γ whenever there is a deduction of A from the set Γ, viewed as a set of premises; from a model theoretic standpoint, A is said to be a consequence of Γ whenever A holds (...) in every model that satisfies each formula in Γ. (shrink)

The purpose of this paper is to explore a new deontic operator for representing what an agent ought to do; the operator is cast against the background of a modal treatment of action developed by Nuel Belnap and Michael Perlo, which itself relies on Arthur Prior's indeterministic tense logic. The analysis developed here of what an agent ought to do is based on a dominance ordering adapted from the decision theoretic study of choice under uncertainty to the present account of (...) action. It is shown that this analysis gives rise to a normal deontic operator, and that the result is superior to an analysis that identi es what an agent ought to do with what it ought to be that the agent does. (shrink)

With precision and profundity born of 30 years of devoted study, John Boyle offers an essential introduction to St. Thomas Aquinas on Scripture, shedding helpful light on the goals, methods, and commitments that animate the Angelic Doctor's engagement with the sacred page. Because the genius of St. Thomas's approach to the Bible lies not so much in its novelty but rather in the fidelity and clarity with which he recapitulates the riches of the preceding interpretive Tradition, this initiation into (...) St. Thomas's vision of Scripture is itself an orientation to the Church's vision of Scripture, from the Fathers through and beyond the Middle Ages. St. Thomas's embeddedness within the Church's Tradition and his own historical context is integral to his approach to Scripture, yet it sets him at some distance from modern readers, for whom his interpretive vision may seem perplexing or even impenetrable. In this Primer, Boyle first provides an acclimation to this medieval context through a survey and explanation of pertinent technical terminology used by St. Thomas and characteristic of the scholastic theology of the time. With an eye to the medieval practice of considering Scripture according to the fourfold division of causes, Boyle builds on this initial foundation by exploring in turn St. Thomas's accounts of the end or use of Scripture (final cause), its divine and human authorship (efficient cause), its order and division (material cause), and its literary styles or genres (formal cause). Drawing on writings from across St. Thomas's corpus, but especially his work On the Commendation and Division of Sacred Scripture and the prologues to his biblical commentaries, Boyle masterfully elucidates both the hermeneutical principles and deep wisdom of the Angelic Doctor's approach to Scripture, imparting invaluable guidance not only for reading and understanding St. Thomas and other great masters of the Tradition, but also-and ultimately-for understanding Scripture in light of this Tradition and reading it with greater benefit and joy. (shrink)

The proofs of the existence of God in part 4 of Descartes’s Discourse on Method may yet surprise us. These arguments appear to be crafted with such ambiguity that their deeper import has rarely been suspected. This essay proposes that, in spite of the text’s conventional appearance, Descartes exposes the error of scholastic metaphysics, namely, that it mistakes the perfectibility of the human mind for a transcendent perfect being. Superficially, the thinker’s “idea of a more perfect being” serves to ground (...) the traditional theology; but surreptitiously, this idea refers to human possibility and supplies the metaphysical basis for scientific progress, freed from theology altogether. This ironic result is obtained not by speculating on Descartes’s irony directly, but by submitting the “idea of a more perfect being” itself to the Cartesian test of truth and falsehood. In that light, the text’s proofs of God reveal their skeptical, philanthropic intent. (shrink)

Whiskey Lao -- Fair warning -- Randomness at large -- We the addicted -- The best possible world -- The importance of being doomed -- Moral responsibility -- The upper limit to the value of possible worlds.

This was designed for all instructors who teach aspects of biological evolution in their college courses.

_Studies in Hermias’ Commentary on Plato’s_ Phaedrus is a collection of twelve essays that consider aspects of Hermias’ philosophy, including his notions of the soul, logic, and method of exegesis.

A key philosophical feature of Peter Jackson’s film interpretation of J.R.R. Tolkien’s The Lord of the Rings is its use of fantasy to inspire a “recovery” of the actual or, in other words, a reawakening to the beauty of nature and the many possible ways of living in healthier ecological relation to the world. Though none of these ways is perfectly achieved, this pluralistic view is demonstrated in the various lifeways of Hobbits, Elves, Men, and Ents. All of the positive (...) relationships embodied in the films—to trees, mountains, horses, and vegetable gardens—involve loving care and attention, receiving nourishment and livelihood without instrumentalization, or reducing nature to mere resource. The films also vividly display a variety of ugly and destructive ways of using the land to accrue power and wealth. These noxious ways, specifically because they actively destroy the lands that they use, always need more. They will thus eventually annihilate the beautiful ways of being if they are not actively resisted. Some of those who would rather be tending their own trees, gardens, or horses or even wandering in the wild forests must therefore turn their attention to struggle and resistance instead. This is a struggle full of grief, and at times even verging on despair, but it is marked by the refusal to give up hope. Indeed, what Jackson and Tolkien have to say about hope is as important in responding to the ecological crisis as anything they have to say about nature, inasmuch as they help to remind us that even in our own times, “there is still hope.”. (shrink)

IN 1903, commenting on an article he had written more than thirty years before, Charles Peirce said that he had changed his mind on many issues at least a half-dozen times but had "never been able to think differently on that question of nominalism and realism" (1.20). For anyone acquainted with Peirce's writings, this remark alone could justify a study of "that question.".

This article extends earlier research concerning the relationship between corporate social performance and corporate financial performance, with particular emphasis on methodological inconsistencies. Research in this area is extended in three critical areas. First, it focuses on a particular industry, the chemical industry. Second, it uses multiple sources of data-two that are perceptual based (KLD Index and Fortune reputation survey), and two that are performance based (TRI database and corporate philanthropy) in order to triangulate toward assessing corporate social performance. Third, it (...) uses the five most commonly applied accounting measures in the corporate social performance and corporate financial performance (CSP/CFP) literature to assess corporate financial performance. The results indicate that the a priori use of measures may actually predetermine the CSP/CFP relationship outcome. Surprisingly, Fortune and KLD indices very closely track one another, whereas TRI and corporate philanthropy differentiate between high and low social performers and do not correlate to the firm's financial performance. (shrink)

Jaynes's maximum entropy principle (MEP) is analyzed by considering in detail a recent controversy. Emphasis is placed on the inductive logical interpretation of “probability” and the concept of “total knowledge.” The relation of the MEP to relative frequencies is discussed, and a possible realm of its fruitful application is noted.

It is assumed that experiments yield results that are not isomorphic with reality, but represent a distorted image of reality. Reality is related to observation via a communication channel of finite capacity. Quantum uncertainties are due to the bound on the amount of information available. Use is made of recent results from information and communication theories.

John F. Post argues that physicalistic materialism is compatible with a number of views often deemed incompatible with it, such as the objectivity of values, the irreducibility of subjective experience, the power of the metaphor, the normativity of meaning, and even theism.

Originally published in 1830, this book can be called the first modern work in the philosophy of science, covering an extraordinary range of philosophical, methodological, and scientific subjects. "Herschel's book . . . brilliantly analyzes both the history and nature of science."—Keith Stewart Thomson, American Scientist.