Pollock describes an exciting theory of rationality and its partial implementation in OSCAR, a computer system whose descendants will literally be persons.

This new edition of the classic Contemporary Theories of Knowledge has been significantly updated to include analyses of the recent literature in epistemology.

There was a long tradition in philosophy according to which good reasoning had to be deductively valid. However, that tradition began to be questioned in the 1960’s, and is now thoroughly discredited. What caused its downfall was the recognition that many familiar kinds of reasoning are not deductively valid, but clearly confer justification on their conclusions. Here are some simple examples.

Probability is sometimes regarded as a universal panacea for epistemology. It has been supposed that the rationality of belief is almost entirely a matter of probabilities. Unfortunately, those philosophers who have thought about this most extensively have tended to be probability theorists first, and epistemologists only secondarily. In my estimation, this has tended to make them insensitive to the complexities exhibited by epistemic justification. In this paper I propose to turn the tables. I begin by laying out some rather simple (...) and uncontroversial features of the structure of epistemic justification, and then go on to ask what we can conclude about the connection between epistemology and probability in the light of those features. My conclusion is that probability plays no central role in epistemology. This is not to say that probability plays no role at all. In the course of the investigation, I defend a pair of probabilistic acceptance rules which enable us, under some circumstances, to arrive at justified belief on the basis of high probability. But these rules are of quite limited scope. The effect of there being such rules is merely that probability provides one source for justified belief, on a par with perception, memory, etc. There is no way probability can provide a universal cure for all our epistemological ills. (shrink)

Logical Options introduces the extensions and alternatives to classical logic which are most discussed in the philosophical literature: many-sorted logic, second-order logic, modal logics, intuitionistic logic, three-valued logic, fuzzy logic, and free logic. Each logic is introduced with a brief description of some aspect of its philosophical significance, and wherever possible semantic and proof methods are employed to facilitate comparison of the various systems. The book is designed to be useful for philosophy students and professional philosophers who have learned some (...) classical first-order logic and would like to learn about other logics important to their philosophical work. (shrink)

As a high school student, I rediscovered Hume’s problem of induction on my own. For a while, I was horrified. I thought, “We cannot know anything!” After a couple of weeks I calmed down and reasoned that there had to be something wrong with my thinking, and that led me quickly to the realization that good reasons need not be deductive, and to the discovery of defeasible reasoning. From there it was a short jump to a more general interest in (...) how rational cognition works. I am interested in rational cognition in general. Epistemology is one constituent of rational cognition, practical cognition (rational decision making) another. Much of the work on rational cognition begins with the supposition that only ideal agents can be truly rational. Real agents have limited powers of reasoning and limited memory capacity. It is often supposed that such resource-bounded agents can only approximate rationality, and that as philosophers we should confine our attention to ideal agents. If one wishes, one can of course define “rationality” in this way, but this has never been what interested me. We come to philosophy wondering what we should believe, what we should do, and how we should go about deciding these matters. These are questions about ourselves, with all of our cognitive limitations. For example, it is often claimed that ideal agents, with unlimited cognitive powers, should believe all of the logical consequences of their beliefs. But we, as real resource-bounded agents, cannot do that, so that is not something we should do. What I want to know is how I, as a real agent, should go about deciding what to believe and what to do. Thus my topic is real rationality as opposed to ideal rationality. In the realm of practical decision making, I have explored this distinction at great length in my recent book (2006). Here I will focus on its implications for epistemology. For many years epistemology was derailed by the Gettier problem.. (shrink)

Recent scholarship has inquired into the socio-historical, discursive genesis of trauma. Trauma and the Ontology of the Modern Subject, however, seeks what has not been actualized in trauma studies - that is, how the necessity and unassailable intensity of trauma is fastened to its historical emergence. We must ask not only what trauma means for the individual person's biography, but also what it means to be the historical subject of trauma. In other words, how does being human in this current (...) period of history implicate one's lived possibilities that are threatened, and perhaps framed, through trauma? Foucauldian sensibilities inform a critical and structural analysis that is hermeneutically grounded. Drawing on the history of ideas and on Lacan's work in particular, John L. Roberts argues that what we mean by trauma has developed over time, and that it is intimately tied with an ontology of the subject; that is to say, what it is to be, and means to be human. He argues that modern subjectivity - as articulated by Heidegger, Levinas, and Lacan - is structurally traumatic, founded in its finitude as self-withdrawal in time, its temporal self-absence becoming the very conditions for agency, truth and knowledge. The book also argues that this fractured temporal horizon - as an effect of an interrupting Otherness or alterity - is obscured through the discourses and technologies of the psy-disciplines (psychiatry, psychology, and psychotherapy). Consideration is given to social, political, and economic consequences of this concealment. Trauma and the Ontology of the Modern Subject will be of enduring interest to psychoanalysts and psychotherapists as well as scholars of philosophy and cultural studies. (shrink)

This book explores and articulates the concepts of the continuous and the infinitesimal from two points of view: the philosophical and the mathematical. The first section covers the history of these ideas in philosophy. Chapter one, entitled ‘The continuous and the discrete in Ancient Greece, the Orient and the European Middle Ages,’ reviews the work of Plato, Aristotle, Epicurus, and other Ancient Greeks; the elements of early Chinese, Indian and Islamic thought; and early Europeans including Henry of Harclay, Nicholas of (...) Autrecourt, Duns Scotus, William of Ockham, Thomas Bradwardine and Nicolas Oreme. The second chapter of the book covers European thinkers of the sixteenth and seventeenth centuries: Galileo, Newton, Leibniz, Descartes, Arnauld, Fermat, and more. Chapter three, 'The age of continuity,’ discusses eighteenth century mathematicians including Euler and Carnot, and philosophers, among them Hume, Kant and Hegel. Examining the nineteenth and early twentieth centuries, the fourth chapter describes the reduction of the continuous to the discrete, citing the contributions of Bolzano, Cauchy and Reimann. Part one of the book concludes with a chapter on divergent conceptions of the continuum, with the work of nineteenth and early twentieth century philosophers and mathematicians, including Veronese, Poincaré, Brouwer, and Weyl. Part two of this book covers contemporary mathematics, discussing topology and manifolds, categories, and functors, Grothendieck topologies, sheaves, and elementary topoi. Among the theories presented in detail are non-standard analysis, constructive and intuitionist analysis, and smooth infinitesimal analysis/synthetic differential geometry. No other book so thoroughly covers the history and development of the concepts of the continuous and the infinitesimal. (shrink)

Perkins, John L With his regular programmes on radio and television, newspaper columns and commentary, Waleed Aly has become Australia's favourite Muslim celebrity. He is intelligent, articulate and provides incisive analysis of political and social issues. Given this, it might have been expected that he could have applied the same quality of analysis in his book, People Like Us: How Arrogance is Dividing Islam and the West (2007); however this is not the case.

It has long been claimed that Homo sapiens is the only species that has language, but only recently has it been recognized that humans also have an unusual pattern of growth and development. Social mammals have two stages of pre-adult development: infancy and juvenility. Humans have two additional prolonged and pronounced life history stages: childhood, an interval of four years extending between infancy and the juvenile period that follows, and adolescence, a stage of about eight years that stretches from juvenility (...) to adulthood. We begin by reviewing the primary biological and linguistic changes occurring in each of the four pre-adult ontogenetic stages in human life history. Then we attempt to trace the evolution of childhood and juvenility in our hominin ancestors. We propose that several different forms of selection applied in infancy and childhood; and that, in adolescence, elaborated vocal behaviors played a role in courtship and intrasexual competition, enhancing fitness and ultimately integrating performative and pragmatic skills with linguistic knowledge in a broad faculty of language. A theoretical consequence of our proposal is that fossil evidence of the uniquely human stages may be used, with other findings, to date the emergence of language. If important aspects of language cannot appear until sexual maturity, as we propose, then a second consequence is that the development of language requires the whole of modern human ontogeny. Our life history model thus offers new ways of investigating, and thinking about, the evolution, development, and ultimately the nature of human language. (shrink)

Stuart Russell [14] describes rational agents as --œthose that do the right thing--�. The problem of designing a rational agent then becomes the problem of figuring out what the right thing is. There are two approaches to the latter problem, depending upon the kind of agent we want to build. On the one hand, anthropomorphic agents are those that can help human beings rather directly in their intellectual endeavors. These endeavors consist of decision making and data processing. An agent that (...) can help humans in these enterprises must make decisions and draw conclusions that are rational by human standards of rationality. Anthropomorphic agents can be contrasted with goal-oriented agents --” those that can carry out certain narrowly-defined tasks in the world. Here the objective is to get the job done, and it makes little difference how the agent achieves its design goal. (shrink)

Traditionally, expressions in formal systems have been regarded as signifying finite inscriptions which are—at least in principle—capable of actually being written out in primitive notation. However, the fact that (first-order) formulas may be identified with natural numbers (via "Gödel numbering") and hence with finite sets makes it no longer necessary to regard formulas as inscriptions, and suggests the possibility of fashioning "languages" some of whose formulas would be naturally identified as infinite sets . A "language" of this kind is called (...) an infinitary language : in this article I discuss those infinitary languages which can be obtained in a straightforward manner from first-order languages by allowing conjunctions, disjunctions and, possibly, quantifier sequences, to be of infinite length. In the course of the discussion it will be seen that, while the expressive power of such languages far exceeds that of their finitary (first-order) counterparts, very few of them possess the "attractive" features (e.g., compactness and completeness) of the latter. Accordingly, the infinitary languages that do in fact possess these features merit special attention. (shrink)

For this second edition, the editors have returned to Austin's original lecture notes, amending the printed text where it seemed necessary.

Summary In the trial of Galileo there is a small but significant discrepancy between the text of his condemnation by the Holy Office and the text of his recantation, which has been generally overlooked or ignored. The offence that he was required to recant was more serious than the one of which he had been found guilty. The most plausible explanation seems to be that the two texts were drawn up independently of each other by the Inquisitors and the Pope (...) respectively, and that the latter wished to deal more harshly with Galileo than the former. There is some independent evidence for this supposition. (shrink)

The traditional paradigm for research relating to the Fishbeinian model of intention is described and some of its limitations are discussed. A structuralist interpretation of the Fishbeinian equation is then put forward from the standpoint of the ethogenic perspective advocated by Harré and Secord. Each component of the Fishbeinian equation is assumed to be the symbolic expression of an account which is attributable to the agent and relates to the act in question. The equation as a whole is then interpreted (...) as a rule governing the intelligibility of a cluster of such accounts. Empirical studies are reported which examine the consequences of transgressing the rule of intelligibility and which use instances of transgression as a means to theoretical development. In this development, the importance of the executive facet of action is acknowledged by utilising Abelson's schemes for the representation of plans. The paper concludes with a speculative discussion as to how this radically different conceptual and methodological approach might be used in future research on the intention-behaviour relation. (shrink)

As his editor John L. Stanley points out, Georges Sorel was "that fascinating polymath." This volume, the third in his selected works in the English language published by Transaction, emphasizes Sorel's extraordinary writings in the philosophy of science, religion, culture, and art. For those who know Sorel only as author of Reflections on Violence, the present volume will come as a forceful reminder of the range and depth of Sorelian efforts to construct a world view. Sorel is throughout concerned (...) with the moral development of human beings. In this sense, his writings on politics are of a piece with his writings on religion, "facticity" of human history and society. Sorel's earliest writings were on religion, and key portions of that period are reflected in selections here. And he went on from there to study the sociology of science, the ways in which science fits into the cultural history of civilization and present day social relationships of industrial society. Stanley provides a profound framework based on two decades of close study and translation of Sorel's texts. He helps to explain how the partial theories of Sorel lead to holistic intellectual consequences, how the psychological method does not foreclose political activism, and how historical limits can be transformed against a background of aesthetics or considerations of taste. He shows that Sorel comes as a close as Manheim and Simmel and Durkheim to the creation of a modern social science--albeit he lacks the overall philosophical theorems of people like Marx and Weber. In Sorel we have a first-class mind at work. And in Stanley, we have a first-class analyst at work. Together, the volume adds up to something special for the political scientist, sociologist, art historian, theologian--in short for those to whom the ideal of a human science endures. John L. Stanley is professor of political science at the University of California at Riverside. He is the author of The Sociology of Virtue: The Political and Social Theories of Georges Sorel. He has written many articles and reviews on the history of European political theory. With his wife, Charlotte Stanley, he has been long engaged in the translation of the works of Georges Sorel. (shrink)

Examples growing out of the Newcomb problem have convinced many people that decision theory should proceed in terms of some kind of causal probability. I endorse this view and define and investigate a variety of causal probability. My definition is related to Skyrms' definition, but proceeds in terms of objective probabilities rather than subjective probabilities and avoids taking causal dependence as a primitive concept.

In this article a dialectical model for practical reasoning within a community, based on the Generic/Actual Argument Model (GAAM) is advanced and its application to deliberative dialogue discussed. The GAAM, offers a dynamic template for structuring knowledge within a domain of discourse that is connected to and regulated by a community. The paper demonstrates how the community accepted generic argument structure acts to normatively influence both admissible reasoning and the progression of dialectical reasoning between participants. It is further demonstrated that (...) these types of deliberation dialogues supported by the GAAM comply with criteria for normative principles for deliberation, specifically, Alexy’s rules for discourse ethics and Hitchcock’s Principles of Rational Mutual Inquiry. The connection of reasoning to the community in a documented and transparent structure assists in providing best justified reasons, principles of deliberation and ethical discourse which are important advantages for reasoning communities. (shrink)

An argument is self-defeating when it contains defeaters for some of its own defeasible lines. It is shown that the obvious rules for defeat among arguments do not handle self-defeating arguments correctly. It turns out that they constitute a pervasive phenomenon that threatens to cripple defeasible reasoning, leading to almost all defeasible reasoning being defeated by unexpected interactions with self-defeating arguments. This leads to some important changes in the general theory of defeasible reasoning.

This chapter reiterates the proposition that practical cognition should not aim at finding optimal solutions to practical problems. A rational cognizer should instead look for good solutions, and replace them with better solutions if any are found. Solutions come in the form of plans. In general, a change to the master plan may consist of deleting several local plans and adding several others. This theory is still fairly schematic. It leaves most details to the imagination of the reader, and in (...) philosophy, that is often a recipe for disaster. When philosophical theories fail, it is not because they did not look good in the abstract—it is because it is impossible to make the details work. This chapter simply gives a preliminary sketch of how a resource bounded agent can actually perform locally global planning. (shrink)

Some ordinary language philosophers, including Stanley Cavell, have attacked certain tendencies of traditional philosophers as follows. E.g., when we say that something looks red to us, we imply that we think it isn't really red. Thus we arc breaking a rule of language when we say that something looks red to us when we know it is red. And thus there is something logically wrong with the traditional attempt, to say that what justifies us in thinking that something is red (...) is its looking red to us. In this article it is maintained that the ?implication? invoked above is a contingent relation having to do with what makes a fact noteworthy, and that the existence of this implication does not show that there is anything logically wrong with the traditional positions being attacked. (shrink)

Perkins, John L The atrocity of September 11 led me to become an atheist. A boundary had been crossed, I thought, and religions could no longer be regarded as benign. As the buildings crashed to the ground in New York, this conclusion seemed obvious. Yet a decade and a half later, it seems remarkable how few people have been able to reach the same conclusion.