Richard Jeffrey is beyond dispute one of the most distinguished and influential philosophers working in the field of decision theory and the theory of knowledge. His work is distinctive in showing the interplay of epistemological concerns with probability and utility theory. Not only has he made use of standard probabilistic and decision theoretic tools to clarify concepts of evidential support and informed choice, he has also proposed significant modifications of the standard Bayesian position in order that it provide a (...) better fit with actual human experience. Probability logic is viewed not as a source of judgment but as a framework for explaining the implications of probabilistic judgments and their mutual compatability. This collection of essays spans a period of some 35 years and includes what have become some of the classic works in the literature. There is also one completely new piece, while in many instances Jeffrey includes afterthoughts on the older essays. (shrink)
This brief paperback is designed for symbolic/formal logic courses. It features the tree method proof system developed by Jeffrey. The new edition contains many more examples and exercises and is reorganized for greater accessibility.
Logicism Lite counts number‐theoretical laws as logical for the same sort of reason for which physical laws are counted as as empirical: because of the character of the data they are responsible to. In the case of number theory these are the data verifying or falsifying the simplest equations, which Logicism Lite counts as true or false depending on the logical validity or invalidity of first‐order argument forms in which no numbertheoretical notation appears.
Isaac Levi and I have different views of probability and decision making. Here, without addressing the merits, I will try to answer some questions recently asked by Levi (1985) about what my view is, and how it relates to his.
We present a general framework for representing belief-revision rules and use it to characterize Bayes's rule as a classical example and Jeffrey's rule as a non-classical one. In Jeffrey's rule, the input to a belief revision is not simply the information that some event has occurred, as in Bayes's rule, but a new assignment of probabilities to some events. Despite their differences, Bayes's and Jeffrey's rules can be characterized in terms of the same axioms: "responsiveness", which requires (...) that revised beliefs incorporate what has been learnt, and "conservativeness", which requires that beliefs on which the learnt input is "silent" do not change. To illustrate the use of non-Bayesian belief revision in economic theory, we sketch a simple decision-theoretic application. (shrink)
This essay explains Jeffrey Friedman's two fundamental and persistent philosophical errors concerning the libertarian conception of liberty and the lack of a "justification‟ of libertarianism. It is ironic that Friedman himself is thereby revealed to be guilty of both an “a priori” anti-libertarianism and an anti-libertarian “straddle.” Critical-rationalist, proactive-imposition-minimising libertarianism remains completely unchallenged by him.
I show that David Lewis’s principal principle is not preserved under Jeffrey conditionalization. Using this observation, I argue that Lewis’s reason for rejecting the desire as belief thesis and Adams’s thesis applies also to his own principal principle. 1 Introduction2 Adams’s Thesis, the Desire as Belief Thesis, and the Principal Principle3 Jeffrey Conditionalization4 The Principal Principles Not Preserved under Jeffrey Conditionalization5 Inadmissible Experiences.
Este trabalho monográfico busca pesquisar a teologia da Oração Eucarística II, em seus aspectos teológicos e históricos. Para tanto, buscou-se estudar a Anáfora Eucarística de Hipólito de Roma em sua obra – Traditio Apostolica, este é um texto patrístico do século III, onde se encontram alguns aspectos da Liturgia em Roma. Investigando o texto anafórico hipolitano constata-se que a Comissão responsável pela confecção das novas Preces Eucarísticas retoma o texto anafórico de Hipólito de Roma. Nosso artigo busca possibilitar o conhecimento (...) deste dado em perspectiva de uma possível comparação com a Oração Eucarística II do Missal Romano de Paulo VI, esta Anáfora é de 1968, em vista de um ulterior trabalho de pesquisa. Nosso estudo conduz a perceber as interpolações entre a Anáfora de Hipólito e a Prece Eucarística II. Por fim, nosso estudo não vislumbra esgotar o tema abordado, mas possibilitar uma via de novos estudos acerca da Teologia Eucarística a partir da lex orandi. (shrink)
Jonathan Weisberg has argued that Jeffrey Conditioning is inherently “anti-holistic” By this he means, inter alia, that JC does not allow us to take proper account of after-the-fact defeaters for our beliefs. His central example concerns the discovery that the lighting in a room is red-tinted and the relationship of that discovery to the belief that a jelly bean in the room is red. Weisberg’s argument that the rigidity required for JC blocks the defeating role of the red-tinted light (...) rests on the strong assumption that all posteriors within the distribution in this example are rigid on a partition over the proposition that the jelly bean is actually red. But individual JC updates of propositions do not require such a broad rigidity assumption. Jeffrey conditionalizers should consider the advantages of a modest project of targeted updating focused on particular propositions rather than seeking to update the entire distribution using one obvious partition. Although Weisberg’s example fails to show JC to be irrelevant or useless, other problems he raises for JC (the commutativity and inputs problems) remain and actually become more pressing when we recognize the important role of background information. (shrink)
This paper discusses simultaneous belief updates. I argue here that modeling such belief updates using the Principle of Minimum Information can be regarded as applying Jeffrey conditionalization successively, and so that, contrary to what many probabilists have thought, the simultaneous belief updates can be successfully modeled by means of Jeffrey conditionalization.
In his introduction, Jeffrey Metzger states that “at some point in the past 20 or 30 years … Nietzsche’s name [became] no longer associated primarily with nihilism” (1). Metzger is pointing to the increasing contemporary scholarly interest in Nietzsche’s epistemology, naturalism, and metaethics. The worthy aim of this volume is to ask us to examine once again the underlying philosophical problem to which these views are a response, namely, nihilism. This volume helpfully reminds us that Nietzsche’s philosophical motivation still (...) requires clarification, and that we can only fully understand Nietzsche’s particular views by grasping Nietzsche’s fundamental philosophical aims.As with so many edited volumes on .. (shrink)
Bayesian decision theory can be viewed as the core of psychological theory for idealized agents. To get a complete psychological theory for such agents, you have to supplement it with input and output laws. On a Bayesian theory that employs strict conditionalization, the input laws are easy to give. On a Bayesian theory that employs Jeffrey conditionalization, there appears to be a considerable problem with giving the input laws. However, Jeffrey conditionalization can be reformulated so that the problem (...) disappears, and in fact the reformulated version is more natural and easier to work with on independent grounds. (shrink)
There are cases of ineffable learning — i. e., cases where an agent learns something, but becomes certain of nothing that she can express — where it is rational to update by Jeffrey conditionalization. But there are likewise cases of ineffable learning where updating by Jeffrey conditionalization is irrational. In this paper, we first characterize a novel class of cases where it is irrational to update by Jeffrey conditionalization. Then we use the d-separation criterion to develop a (...) causal understanding of when and when not to Jeffrey conditionalize that bars updating by Jeffrey conditionalization in these cases. Finally, we reflect on how the possibility of so-called “unfaithful” causal systems bears on the normative force of the causal updating norm that we advocate. (shrink)
We propose a method of learning indicative conditional information. An agent learns conditional information by Jeffrey imaging on the minimally informative proposition expressed by a Stalnaker conditional. We show that the predictions of the proposed method align with the intuitions in Douven, 239–263 2012)’s benchmark examples. Jeffrey imaging on Stalnaker conditionals can also capture the learning of uncertain conditional information, which we illustrate by generating predictions for the Judy Benjamin Problem.
Suppose that several individuals who have separately assessed prior probability distributions over a set of possible states of the world wish to pool their individual distributions into a single group distribution, while taking into account jointly perceived new evidence. They have the option of first updating their individual priors and then pooling the resulting posteriors or first pooling their priors and then updating the resulting group prior. If the pooling method that they employ is such that they arrive at the (...) same final distribution in both cases, the method is said to be externally Bayesian, a property first studied by Madansky . We show that a pooling method for discrete distributions is externally Bayesian if and only if it commutes with Jeffrey conditioning, parameterized in terms of certain ratios of new to old odds, as in Wagner , rather than in terms of the posterior probabilities of members of the disjoint family of events on which such conditioning originates. (shrink)
Studies of categorical induction typically examine how belief in a premise (e.g., Falcons have an ulnar artery) projects on to a conclusion (e.g., Robins have an ulnar artery). We study induction in cases in which the premise is uncertain (e.g., There is an 80% chance that falcons have an ulnar artery). Jeffrey's rule is a normative model for updating beliefs in the face of uncertain evidence. In three studies we tested the descriptive validity of Jeffrey's rule and a (...) related probability theorem, the rule of total probability. Although these rules provided good approximations to mean judgments in some cases, the results from regression and correlation analyses suggest that participants focus on the parts of these rules that are associated with the highest overall probability. We relate our findings to rational models of judgment. (shrink)
Subjective Probability: The Real Thing is the last book written by the late Richard Jeffrey, a key proponent of the Bayesian interpretation of probability.Bayesians hold that probability is a mental notion: saying that the probability of rain is 0.7 is just saying that you believe it will rain to degree 0.7. Degrees of belief are themselves cashed out in terms of bets—in this case you consider 7:3 to be fair odds for a bet on rain. There are two extreme (...) Bayesian positions. Strict subjectivists think that an agent can adopt whatever degrees of belief she likes, as long as they satisfy the axioms of probability. Thus your degree of belief in rain and degree of belief in no rain must sum to one but are otherwise unconstrained. At the other extreme, objectivists claim that an agent's background knowledge considerably narrows down the choice of appropriate degrees of belief. In particular, if you know only that the frequency of rain is 0.7 then you should believe it will rain to degree 0.7; if you know absolutely nothing about the weather then you should set your degree of belief in rain to be 0.5; in neither of these cases is there room for subjective choice of degree of belief. In this book, Jeffrey advocates what is sometimes called empirically-based subjectivism, a position that lies between the two extremes of strict subjectivism and objectivism. According to this position, knowledge of frequencies constrains degree of belief, but lack of knowledge does not impose any constraints, so that if you know nothing about the weather you may adopt any degree of belief in rain you like.1The aim of the book is not so much to justify this point of view as to provide a comprehensive exposition of probability theory from the …. (shrink)
“[T]here is something rotten at the heart of medicine” —this is one of the central statements of Jeffrey Paul Bishop in his book The Anticipatory Corpse. Medicine, Power and the Care of the Dying. The obvious, if somewhat morbid, thought that “rotten” would refer to the decaying body as the central subject of investigation is, however, misleading. Instead, Bishop aims to demonstrate that the modern trend of medicalizing dying and death is the wrong way.The book explores contemporary medicine’s practices, (...) their historical evolvement, and their underpinnings with regard to the care of the dying. Informed by Foucault’s genealogy of medicine, the book argues that the dead body has become the epistemologically normative body for medicine: medical knowledge of the living body is derived from investigating the dead body. With the help of autopsies, medicine has learned to view life as “matter in motion” and people as moving machines with interchangeable parts. Furthermore, medicine has .. (shrink)
Wittgenstein’s concepts shed light on the phenomenon of schizophrenia in at least three different ways: with a view to empathy, scientific explanation, or philosophical clarification. I consider two different “positive” wittgensteinian accounts―Campbell’s idea that delusions involve a mechanism of which different framework propositions are parts, Sass’ proposal that the schizophrenic patient can be described as a solipsist, and a Rhodes’ and Gipp’s account, where epistemic aspects of schizophrenia are explained as failures in the ordinary background of certainties. I argue that (...) none of them amounts to empathic-phenomenological understanding, but they provide examples of how philosophical concepts can contribute to scientific explanation, and to philosophical clarification respectively. (shrink)
Jeffrey Stout addresses two of the main criticisms of liberal democracy by its contemporary neotraditionalist Christian critics: that liberal democracy is destructive of social tradition, and thereby of virtue in the citizenry, and that liberal democracy is inherently secular, committed to expunging religious voices from the public arena. I judge that Stout effectively answers these charges: liberal democracy has its own tradition, it cultivates the virtues relevant to that, and it is not inherently hostile to piety. What Stout does (...) not do, I suggest, is take the next step of showing, positively, that Christianity can and should affirm the substance of liberal democratic society. This is due, in good measure, to the fact that Stout never tells us, except in off-hand comments, what he takes the substance of liberal democracy to be. And this, in turn, is due to his way of employing pragmatism: he uses pragmatism to give an account of human society generally, not of liberal democratic society. I raise some questions about the general account that pragmatism gives of human society, and thus about the account that it would give of liberal democracy. (shrink)
Richard Jeffrey's generalization of Bayes' rule of conditioning follows, within the theory of belief functions, from Dempster's rule of combination and the rule of minimal extension. Both Jeffrey's rule and the theory of belief functions can and should be construed constructively, rather than normatively or descriptively. The theory of belief functions gives a more thorough analysis of how beliefs might be constructed than Jeffrey's rule does. The inadequacy of Bayesian conditioning is much more general than Jeffrey's (...) examples of uncertain perception might suggest. The ``parameter α '' that Hartry Field has introduced into Jeffrey's rule corresponds to the "weight of evidence" of the theory of belief functions. (shrink)
A glance at the sky raises my probability of rain to .7. As it happens, the conditional probabilities of each state given rain remain the same, and similarly for their conditional probabilities given no rain. As Jeffrey (1983, Ch. 11) points out, my new distribution P2 is therefore fixed by the law of total probability. For example, P2(RC) = P2(RC | R)P2(R)+P2(RC | ¯.
Oaksford & Chater (O&C) begin in the halfway Bayesian house of assuming that minor premises in conditional inferences are certain. We demonstrate that this assumption is a serious limitation. They additionally suggest that appealing to Jeffrey's rule could make their approach more general. We present evidence that this rule is not limited enough to account for actual probability judgements.
A very important event took place on January 15, 2017. On that day, the Jeffrey Beall blog was silently, and suddenly, shut down by Beall himself. A profoundly divisive and controversial site, the Beall blog represented an existential threat to those journals and publishers that were listed there. On the other hand, the Beall blog was a ray of hope to critics of bad publishing practices that a culture of public shaming was perhaps the only way to rout out (...) those journals—and their editors—and publishers who did not respect basic publishing ethical principles and intrinsic academic values. While members of the former group vilified Beall and his blog, members of the latter camp tried to elevate it to the level of policy. Split by extreme polar forces, for reasons still unknown to the public, Beall deliberately shut down his blog, causing some academic chaos among global scholars, including to the open access movement. (shrink)
This paper traces developments in Jeffrey Alexander’s cultural sociology. The aim is to introduce the reader to the key components of this theory as it developed from a functionalist focus on societal values through semiotics and linguistic structuralism to a theory of cultural trauma and collective performance.
In this commentary, after first summarizing the three major theses of Jeffrey's paper Probability and Falsification: Critique of the Popper Program, and sketching out what I take to be his central argument, I criticize Jeffrey on two grounds. The first is that he has failed to explain why his version of Bayesianism provides us with better theories upon which to make decisions; the second is that he has offered a theory about decision-making that by-passes the important question: How (...) can we make more rational decisions? (shrink)
I respond to Jeffrey Bishop’s article ‘Arts of Dying and the Statecraft of Killing’, in this issue, and in particular to his remarks in support of the claim that assisted death should not be legalised.
Though there is no escape from the recognition of the community-dependent quality of moral knowledge, Jeffrey Stout is right to affirm the possibility of value-laden communication across community boundaries. My quarrel is not with his affirmation but with his effort to defend that affirmation by falling back on the project of establishing some universally recognized prohibition. I draw a contrasting model from the sixth century prophets in order to recast the question in light of the actual, powerful, transformative telling (...) of "good news" by one particular people to another. Concerning the possibility of such barrier-bridging communication, there is a long and venerable history of success that has not been accorded its due weight, perhaps because we are not accustomed to looking to the fields of translation and mission work for guidance in addressing moral and philosophical problems. (shrink)
A simple rule of probability revision ensures that the final result of a sequence of probability revisions is undisturbed by an alteration in the temporal order of the learning prompting those revisions. This Uniformity Rule dictates that identical learning be reflected in identical ratios of certain new-to-old odds, and is grounded in the old Bayesian idea that such ratios represent what is learned from new experience alone, with prior probabilities factored out. The main theorem of this paper includes as special (...) cases Field's theorem on commuting probability-kinematical revisions and the equivalence of two strategies for generalizing Jeffrey 's solution to the old evidence problem to the case of uncertain old evidence and probabilistic new explanation. (shrink)
Jeffrey Gray’s Consciousness: Creeping up on the Hard Problem will be enjoyed by everyone interested in consciousness. Gray, a neuropsychologist, eloquently summarizes significant experimental results on consciousness and, more importantly, explains both how these results interrelate and how they constrain potential theories of consciousness. He also uses these results to build a novel, fascinating theory of what consciousness does and does not do. Throughout the work Gray’s accessible presentation remains deeply respectful of psychologists, neuroscientists, and philosophers’ approaches to consciousness. (...) In this respect, Gray’s book is an ideal work for an interdisciplinary audience. Sadly, Gray died three months before the publication of this excellent work. (shrink)
Jeffrey Tillman is perceptive in noticing that certain Protestant theologians have used evolutionary theory to become more sympathetic to Roman Catholic views of Christian love. But he is incorrect in saying that these formulations deemphasize a place for self-sacrifice in Christian love. Christian love defined as a strenuous equal-regard for both other and self also requires sacrificial efforts to restore love as equal-regard when finitude and sin undermine genuine mutuality and community.
In Tsuji 1997 the concept of Jeffrey-Keynes algebras was introduced in order to construct a paraconsistent theory of decision under uncertainty. In the present paper we show that these algebras can be used to develop a theory of decision under uncertainty that measures the degree of belief on the quasi (or partial) truth of the propositions. As applications of this new theory of decision, we use it to analyze Popper's paradox of ideal evidence and to indicate a possible way (...) of formalizing Keynes' theory of economic action. (shrink)
This paper is partly a tribute to Richard Jeffrey, partly a reflection on some of his writings, The Logic of Decision in particular. I begin with a brief biography and some fond reminiscences of Dick. I turn to some of the key tenets of his version of Bayesianism. All of these tenets are deployed in my discussion of his response to the St. Petersburg paradox, a notorious problem for decision theory that involves a game of infinite expectation. Prompted by (...) that paradox, I conclude with some suggestions of avenues for future research. (shrink)
The practice of social theory is too often given to celebrity hunting, the polemical vulgarizing of one’s putative enemies, or the precocious production of totalizing and redemptive theories purporting to rescue social theory from its perennial crises of meaning, naming and explanation. The constructive task of social theory, however, can be both more modest and productive when attention is given to its substantive concern to provide codes, narratives and explanations of modernity, in all its pluralist and democratic dimensions. This is (...) in effect the self-description of Jeffrey Alexander’s own work. This paper provides an empathetic account of Alexander’s approach to the practice of social theory via a synopsis of his collected essays in Fin de Siècle Social Theory (1995). In particular, it claims that Alexander’s critique of the reductionist propensities of Pierre Bourdieu’s macro-sociological theory is exemplary in its constructive cast as a systematic analysis of the universalizing contents of the conceptual and methodological claims themselves. Herein lies the use of reason itself. (shrink)
Since the beginning of the ?eighties of the present century, a circle of relatively young American sociologists who are followers of Jeffrey Alexander are making energetic and spectacular efforts to supply sociology with a uniform and comprehensive theoretical framework by continuing Talcott Parsons' lifework. The present article is an appreciation of Alexander's achievements in the justification of a general sociological theory (especially a theory of action and social order) while pointing to objections that can be raised against the character (...) of his theory. A scrutiny of Alexander's metatheoretical deliberations and of his interpretations of sociological classics such as Marx, Durkheim, Weber, and Parsons reveals that Alexander's metatheoretical frame is not flexible enough to actually reconstruct the problem situation of the classics. Pointers are given toward a theory of action that is not subject to the antinomy of utilitarianism and normativism, so that it is more adequate and appropriate to the heritage of the sociological classics, both from a theoretical and an interpretative angle. (shrink)