Formal Epistemology

Th e basi c pu r pos e o f thi s w or k consist s o f eliminatin g som e o f th e m yth s an d paradigms tha t cu r rent ly info r m th e assessmen t o f scienti f i c e vidence . I n orde r t o accomplis h this object i v e , th e autho r sta r t s fro m th e (...) premis e tha t thes e m yth s an d paradigms , produce d with th e d ev elopmen t o f forensi c science , ar e minimizin g th e rol e o f judge s i n judicia l proceedings fo r th e bene f i t o f e xpe r ts . Thi s ca n lea d t o a violatio n o f du e proces s an d n e glectin g that judicia l processe s ar e aime d a t resolvin g conflicts . Th e autho r refer s speci f ical l y t o th e m yth o f in f allibilit y an d th e pa r adig m o f identi f ication , accordin g t o w hic h scienti f i c e vidence ca n posit i v e ly identif y a n ind i vidua l o r objec t throug h p h ysica l traces . B y ana l yzin g the recen t doctrin e o n th e assessmen t o f scienti f i c e vidence , th e autho r conclude s o n th e need t o adop t th e pa r adig m o f likelihood . Thus , th e judg e stil l hold s th e rol e i n th e ev aluation o f e vidence , an d guarantee s tha t th e goal s o f th e proces s wil l b e respected. (shrink)

This paper presents the Futurium platform used by Digital Futures, a foresight project launched by the European Commission's Directorate General for Communications Networks, Content and Technology (DG CONNECT). Futurium was initially developed with the primary purpose of hosting and curating visions and policy ideas generated by Digital Futures (Digital Futures was launched in July 2011 by DG CONNECT's Director General Robert Madelin following a prior DG CONNECT exercise called Digital Science.). However, it has turned into a platform on which to (...) experiment with new policymaking models based on scientific evidence and stakeholder participation, referred to in this paper as ‘Policy Making 3.0’. The platform hosts an online foresight toolkit to facilitate the joint creation of ideas to help design future policies. It leverages the potential of social networks, open data, semantic and knowledge mining technologies as well as participatory brainstorming techniques to engage stakeholders and harness their views and creativity to better inform policies that matter to them. The Futurium distinguishes between different variables, reflecting the emotional vs. rational mindsets of the participants, and offers the possibility to frame the engagement and co-creation process into multiple phases of a workflow. Futurium was developed to support Digital Futures, but its open architecture makes it easily adaptable to any policymaking/decision-making context where thinking ahead, participation, scientific evidence and agility are needed. Futurium is an early prototype implementation of the Policy Making 3.0 model, which is a long-term vision requiring further investigation and experimentation. The Futurium production website can be seen here: ec.europa.eu/digital-agenda/futurium. (shrink)

My aim in this dissertation is to develop an evolutionary conception of science based on recent studies in evolution theory, the thermodynamics of non-equilibrium and information theory, as exemplified in the works of Prigogine, Jantsch, Wicken and Gatlin. ;The nature of scientific change is of interest to philosophers and historians of science. Some construe it after a revolutionary model , others adopt an evolutionary view . It appears to me that it is possible to construct an evolutionary model encompassing the (...) revolutionary mode as well. The following strategies are employed: A distinction is made between two types of growth: one represents gradual change, the other designates radical transformations, and two principles underlying the process of change, one of conservation, the other of innovation. Science in general, and scientific theories in particular, are looked upon as dissipative structures. These are characterised by openness, irreversibility and self-organisation. In terms of these, one may identify a state of "normal" growth and another of violent fluctuations leading to a new order . These fluctuations are generated by the flow of information coming from the observable world. ;The chief merits of this evolutionary model of the development of science lie in the emphasis it puts on the relation of science to its environment, in the description of scientific change as a process of interaction between internal and external elements , in the enhancement of our understanding progress and rationality in science, and in the post Neo-Darwinian conception of evolution, stressing self-organisation, the innovativeness of the evolutionary process and the trend toward complexification. These features are also manifested in the process of discovery, which is a fundamental part of the scientific enterprise. In addition, a distinction is made between two types of discovery which serves as a criterion for delineating various episodes in the development of science. The evolutionary model further displays a complementarity mode of description on several levels: between science and its milieu, stability and instability, discovery and confirmation. (shrink)

In some recent papers, the authors and Peter Gärdenfors have defined and studied two different kinds of formal operation, conceived as possible representations of the intuitive process of contracting a theory to eliminate a proposition. These are partial meet contraction (including as limiting cases full meet contraction and maxichoice contraction) and safe contraction. It is known, via the representation theorem for the former, that every safe contraction operation over a theory is a partial meet contraction over that theory. The purpose (...) of the present paper is to study the relationship more finely, by seeking an explicit map between the component orderings involved in each of the two kinds of contraction. It is shown that at least in the finite case a suitable map exists, with the consequence that the relational, transitively relational, and antisymmetrically relational partial meet contraction functions form identifiable subclasses of the safe contraction functions, over any theory finite modulo logical equivalence. In the process of constructing the map, as the composition of four simple transformations, mediating notions of bottom and top contraction are introduced. The study of the infinite case remains open. (shrink)

This chapter suggests that evidence should be viewed as a field of study, one to which most disciplines could contribute and from which most could benefit, and that generalisations should be viewed as part of that field. Every argument must be based upon a generalisation that can be stated as a major premise. The relationship between a supporting proposition or propositions and an inferred proposition can be restated in a quasi-deductive form by identifying the generalisation upon which the inference depends. (...) A datum or a proposition can be evidence if and only if it alters the probability, positively or negatively, of a proposition to be inferred. In order to demonstrate that an evidential proposition is relevant, an analyst must be able to identify and articulate a generalisation that justifies the claim that the evidential proposition alters the probability of an inferred proposition. This chapter develops these ideas and presents a method of generalisation-analysis. It also argues that generalisation-analysis is a tool in the field of evidence that could be useful in analysing and critiquing arguments in many disciplines. (shrink)

One of the most important developments over the last twenty years both in logic and in Artificial Intelligence is the emergence of so-called non-monotonic logics. These logics were initially developed by McCarthy [10], McDermott & Doyle [13], and Reiter [17]. Part of the original motivation was to provide a formal framework within which to model cognitive phenomena such as defeasible inference and defeasible knowledge representation, i.e., to provide a formal account of the fact that reasoners can reach conclusions tentatively, reserving (...) the right to retract them in the light of further information. (shrink)

This special issue presents a series of articles focusing on recent work in formal epistemology and formal philosophy. The articles in the latter category elaborate on the notion of context and content and their relationships. This work is not unrelated to recent developments in formal epistemology. Logical models of context, when connected with the representation of epistemic context, are clearly relevant for many issues considered by formal epistemologists. For example, the semantic framework Joe Halpern uses in his article for this (...) issue has been applied elsewhere to solve problems in interactive epistemology. (shrink)

Carlos Alchourrón, Peter Gärdenfors and David Makinson published in 1985 a seminal article on belief change in the Journal of Symbolic Logic. Researchers from various disciplines, from computer science to mathematical economics to philosophical logic, have continued the work first presented in this seminal paper during the last two decades. This paper explores some salient foundational trends that interpret the act of changing view as a decision. We will argue that some of these foundational trends are already present, although only (...) tacitly, in the original article by the AGM trio. Other accounts decidedly depart from the view of contraction and revision presented in this seminal paper. I shall survey various types of theories that progressively depart form the axiomatic treatment defended by AGM. First, I consider theories where rational agents are considered as maximizers as opposed to optimizers ). Second, I consider which feasible set to use in contraction understood as a cognitive decision. This leads to rethink the very notion of what minimal change in contraction is. I shall conclude with some philosophical reflections concerning the sort of epistemological voluntarism that is tacit in seeing change in view as a rational choice. Carlos Alchourrón, Peter Gärdenfors y David Makinson publicaron en 1985 un artículo seminal sobre cambio de creencias en Journal of Symbolic Logic. Investigadores de varias disciplinas, desde la ciencia de la computación hasta la economía matemática y la lógica filosófica, han continuado en las dos últimas décadas esta línea de investigación. Este trabajo explora algunos aspectos fundacionalmente salientes que interpretan el acto de cambio de vista como una decisión. Argumentaremos que algunos de esos aspectos fundacionales ya estaban presentes, aunque solo tácitamente, en el artículo original del trío AGM. Otros abordajes parten decididamente de la contracción y revisión tal como fueran presentadas en el trabajo seminal. Inspeccionaré varios tipos de teorías que progresivamente parten del tratamiento axiomático defendido por AGM. Primero, considero teorías donde los agentes racionales aparecen como maximizadres opuestos a los optimiadores ). Segundo, me pregunto cuál conjunto derrotable debe usarse en una contracción entendida como una decisión cognitiva, lo cual lleva a repensar la importante cuestión de en qué consiste la noción de cambio mínimo en la contracción. Concluiré con algunas reflexiones filosóficas acerca de la suerte de voluntarismo epistemológico que está tácito en la concepción del cambio como una opción racional. (shrink)

Let L be a language containing the modal operator B - for full belief. An information model is a set E of stable L-theories. A sentence is valid if it is accepted in all theories of every model.

We present a decision-theoretically motivated notion of contraction which, we claim, encodes the principles of minimal change and entrenchment. Contraction is seen as an operation whose goal is to minimize loses of informational value. The operation is also compatible with the principle that in contracting A one should preserve the sentences better entrenched than A (when the belief set contains A). Even when the principle of minimal change and the latter motivation for entrenchment figure prominently among the basic intuitions in (...) the works of, among others, Quine and Ullian (1978), Levi (1980, 1991), Harman (1988) and Gärdenfors (1988), formal accounts of belief change (AGM, KM – see Gärdenfors (1988); Katsuno and Mendelzon (1991)) have abandoned both principles (see Rott (2000)). We argue for the principles and we show how to construct a contraction operation, which obeys both. An axiom system is proposed. We also prove that the decision-theoretic notion of contraction can be completely characterized in terms of the given axioms. Proving this type of completeness result is a well-known open problem in the field, whose solution requires employing both decision-theoretical techniques and logical methods recently used in belief change. (shrink)

Gerd Gigerenzer and Thomas Sturm have recently proposed a modest form of what they describe as a normative, ecological and limited naturalism. The basic move in their argument is to infer that certain heuristics we tend to use should be used in the right ecological setting. To address this argument, we first consider the case of a concrete heuristic called Take the Best (TTB). There are at least two variants of the heuristic which we study by making explicit the choice (...) functions they induce, extending these variants of TTB beyond binary choice. We argue that the naturalistic argument can be applied to only one of the two variants of the heuristic; we also argue that the argument for the extension requires paying attention to other “rational” virtues of heuristics aside from efficacy, speed, and frugality. This notwithstanding, we show that there is a way of extending the right variant of TTB to obtain a very well behaved heuristic that could be used to offer a stronger case for the naturalistic argument (in the sense that if this heuristic is used, it is also a heuristic that we should use). The second part of the article considers attempts to extending the naturalistic argument from algorithms dealing with inference to heuristics dealing with choice. Our focus is the so-called Priority Heuristic, which we extend from risk to uncertainty. In this setting, the naturalist argument seems more difficult to formulate, if it remains feasible at all. Normativity seems in this case extrinsic to the heuristic, whose main virtue seems to be its ability to describe actual patterns of choice. But it seems that a new version of the naturalistic argument used with partial success in the case of inference is unavailable to solve the normative problem of whether we should exhibit the patterns of choice that we actually display. (shrink)

We study the relationship between common knowledge and the sequence of iterated mutual knowledge from a topological point of view. It is shown that common knowledge is not equivalent to the limit of the sequence of iterated mutual knowledge. On that account the new epistemic operator limit knowledge is introduced and analyzed in the context of games. Indeed, an example is constructed where the behavioral implications of limit knowledge of rationality strictly refine those of common knowledge of rationality. More generally, (...) it is then shown that limit knowledge of rationality is capable of characterizing any solution concept for some appropriate epistemic-topological conditions. Finally, some perspectives of a topologically enriched epistemic framework for games are discussed. (shrink)

We introduce a distinction, unnoticed in the literature, between four varieties of objective Bayesianism. What we call ' strong objective Bayesianism' is characterized by two claims, that all scientific inference is 'logical' and that, given the same background information two agents will ascribe a unique probability to their priors. We think that neither of these claims can be sustained; in this sense, they are 'dogmatic'. The first fails to recognize that some scientific inference, in particular that concerning evidential relations, is (...) not (in the appropriate sense) logical, the second fails to provide a non-question-begging account of 'same background information'. We urge that a suitably objective Bayesian account of scientific inference does not require either of the claims. Finally, we argue that Bayesianism needs to be fine-grained in the same way that Bayesians fine-grain their beliefs. (shrink)

A central assumption of modern evidence law is that its rules are rules of admissibility only. That is, they tell judges whether or not a given piece of evidence may be viewed by the fact-finder, but they do not purport to tell the finder of fact how to evaluate the evidence once admitted. One can imagine, however, a system of rules that help fact-finders weigh evidence by instructing them, for instance, that the law considers a class of evidence (say, hearsay) (...) to be of "low weight." In fact, such rules - rules of weight - are an old idea with roots in Roman Law. But they have long been ignored by evidence scholars or, when considered, judged to be anachronistic and deeply inconsistent with a system of trial by jury. This Article argues that such hostility to rules of weight is unjustified and that their use should be taken seriously as a possible direction for evidence reform. Given that jury trials are now increasingly rare and that, when a jury is used, its discretion is already constrained in a number of ways, the orthodox view of rules of weight now itself seems outdated. Furthermore, there are reasons to think that such rules could be beneficial for forensic fact-finding. The past use of them by courts, their current role in administrative adjudication, and recent research in cognitive psychology all suggest ways in which rules of weight could make fact-finding fairer, more efficient, and, most important, more accurate. Such benefits make the Supreme Court's recent condemnation of the use of rules of weight in the administrative context that much more difficult to justify. (shrink)

This paper first provides a brief survey of a possibilistic handling of default rules. A set of default rules of the form, "generally, from α deduce β", is viewed as the family of possibility distributions satisfying constraints expressing that the situation where α and β is true has a greater plausibility than the one where α and ⇁β is true. When considering only the subset of linear possibility distributions, the well-known System P of postulates proposed by Kraus, Lehmann and Magidor, (...) has been obtained. We also present two rational extensions: one based on the minimum specificity principle and the other is based on the lexicographic ordering. The second part of the paper presents an empirical study of three desirable properties for a consequence relation that capture default reasoning: Rationality, Property Inheritance and Ambiguity Preservation. An experiment is conducted to investigate 13 patterns of inference for the test of these properties. Our experimental apparatus confirms previous results on the relevance of System P, and enforces the psychological relevance of the studied properties. (shrink)

This article discusses how inference to the best explanation can be justified as a practical meta - argument. It is, firstly, justified as a practical argument insofar as accepting the best explanation as true can be shown to further a specific aim. And because this aim is a discursive one which proponents can rationally pursue in — and relative to — a complex controversy, namely maximising the robustness of one’s position, IBE can be conceived, secondly, as a meta - argument. (...) My analysis thus bears a certain analogy to Sellars ’ well - known justification of inductive reasoning ; it is based on recently developed theories of complex argumentation. (shrink)

We use recently developed approaches in argumentation theory in order to revamp the hypothetico-deductive model of confirmation, thus alleviating the well-known paradoxes the H-D account faces. More specifically, we introduce the concept of dialectic confirmation on the background of the so-called theory of dialectical structures (Betz 2010, 2012b). Dialectic confirmation generalises hypothetico-deductive confirmation and mitigates the raven paradox, the grue paradox, the tacking paradox, the paradox from conceptual difference, and the problem of surprising evidence.