During the past decade a new twist in the debate regarding the a priori has unfolded. A number of prominent epistemologists have challenged the coherence or importance of the a priori—a posteriori distinction or, alternatively, of the concept of a priori knowledge. My focus in this paper is on these new challenges to the a priori. My goals are to provide a framework for organizing the challenges, articulate and assess a range of the challenges, and present two challenges of my (...) own. (shrink)

Deductive inference is usually regarded as being “tautological” or “analytical”: the information conveyed by the conclusion is contained in the information conveyed by the premises. This idea, however, clashes with the undecidability of first-order logic and with the (likely) intractability of Boolean logic. In this article, we address the problem both from the semantic and the proof-theoretical point of view. We propose a hierarchy of propositional logics that are all tractable (i.e. decidable in polynomial time), although by means of growing (...) computational resources, and converge towards classical propositional logic. The underlying claim is that this hierarchy can be used to represent increasing levels of “depth” or “informativeness” of Boolean reasoning. Special attention is paid to the most basic logic in this hierarchy, the pure “intelim logic”, which satisfies all the requirements of a natural deduction system (allowing both introduction and elimination rules for each logical operator) while admitting of a feasible (quadratic) decision procedure. We argue that this logic is “analytic” in a particularly strict sense, in that it rules out any use of “virtual information”, which is chiefly responsible for the combinatorial explosion of standard classical systems. As a result, analyticity and tractability are reconciled and growing degrees of computational complexity are associated with the depth at which the use of virtual information is allowed. (shrink)

Dynamic Epistemic Logic This article tells the story of the rise of dynamic epistemic logic, which began with epistemic logic, the logic of knowledge, in the 1960s. Then, in the late 1980s, came dynamic epistemic logic, the logic of change of knowledge. Much of it was motivated by puzzles and paradoxes. The number … Continue reading Dynamic Epistemic Logic →.

R. Lanier Anderson presents a new account of Kant's distinction between analytic and synthetic judgments, and provides it with a clear basis within traditional logic. He reconstructs compelling claims about the syntheticity of elementary mathematics, and re-animates Kant's arguments against traditional metaphysics in the Critique of Pure Reason.

Contemporary epistemologists typically define a priori justification as justification that is independent of sense experience. However, sense experience plays at least some role in the production of many paradigm cases of a priori justified belief. This raises the question of when experience is epistemically relevant to the justificatory status of the belief that is based on it. In this paper, I will outline the answers that can be given by the two currently dominant accounts of justification, i.e. evidentialism and reliabilism. (...) While for the evidentialist, experience is epistemically relevant only if it is used as evidence, the reliabilist requires that the reliability of the relevant process depends on the reliability of experiential processes. I will argue that the reliabilist account accommodates our pre-theoretic classifications much better. In the final part of my paper I will use the reliabilist criterion to defend the a priori—a posteriori distinction against recent challenges by Hawthorne and Williamson. (shrink)

This book is designed to explain the technical ideas that are taken for granted in much contemporary philosophical writing. Notions like "denumerability," "modal scope distinction," "Bayesian conditionalization," and "logical completeness" are usually only elucidated deep within difficult specialist texts. By offering simple explanations that by-pass much irrelevant and boring detail, Philosophical Devices is able to cover a wealth of material that is normally only available to specialists. The book contains four sections, each of three chapters. The first section is about (...) sets and numbers, starting with the membership relation and ending with the generalized continuum hypothesis. The second is about analyticity, a prioricity, and necessity. The third is about probability, outlining the difference between objective and subjective probability and exploring aspects of conditionalization and correlation. The fourth deals with metalogic, focusing on the contrast between syntax and semantics, and finishing with a sketch of Godel's theorem. Philosophical Devices will be useful for university students who have got past the foothills of philosophy and are starting to read more widely, but it does not assume any prior expertise. All the issues discussed are intrinsically interesting, and often downright fascinating. It can be read with pleasure and profit by anybody who is curious about the technical infrastructure of contemporary philosophy."--p. 4 of cover. (shrink)

Carrie Jenkins presents a new account of arithmetical knowledge, which manages to respect three key intuitions: a priorism, mind-independence realism, and empiricism. Jenkins argues that arithmetic can be known through the examination of empirically grounded concepts, non-accidentally accurate representations of the mind-independent world.

The article addresses the problem of how semantic information can be upgraded to knowledge. The introductory section explains the technical terminology and the relevant background. Section 2 argues that, for semantic information to be upgraded to knowledge, it is necessary and sufficient to be embedded in a network of questions and answers that correctly accounts for it. Section 3 shows that an information flow network of type A fulfils such a requirement, by warranting that the erotetic deficit, characterising the target (...) semantic information t by default, is correctly satisfied by the information flow of correct answers provided by an informational source s. Section 4 illustrates some of the major advantages of such a Network Theory of Account (NTA) and clears the ground of a few potential difficulties. Section 5 clarifies why NTA and an informational analysis of knowledge, according to which knowledge is accounted semantic information, is not subject to Gettier-type counterexamples. A concluding section briefly summarises the results obtained. (shrink)

Luciano Floridi presents a book that will set the agenda for the philosophy of information. PI is the philosophical field concerned with the critical investigation of the conceptual nature and basic principles of information, including its dynamics, utilisation, and sciences, and the elaboration and application of information-theoretic and computational methodologies to philosophical problems. This book lays down, for the first time, the conceptual foundations for this new area of research. It does so systematically, by pursuing three goals. Its metatheoretical goal (...) is to describe what the philosophy of information is, its problems, approaches, and methods. Its introductory goal is to help the reader to gain a better grasp of the complex and multifarious nature of the various concepts and phenomena related to information. Its analytic goal is to answer several key theoretical questions of great philosophical interest, arising from the investigation of semantic information. (shrink)

This article offers an account and defence of constructionism, both as a metaphilosophical approach and as a philosophical methodology, with references to the so-called maker's knowledge tradition. Its main thesis is that Plato's “user's knowledge” tradition should be complemented, if not replaced, by a constructionist approach to philosophical problems in general and to knowledge in particular. Epistemic agents know something when they are able to build (reproduce, simulate, model, construct, etc.) that something and plug the obtained information into the correct (...) network of relations that account for it. Their epistemic expertise increases with the scope and depth of the questions that they are able to ask and answer. Thus, constructionism deprioritises mimetic, passive, and declarative knowledge that something is the case, in favour of poietic, interactive, and practical knowledge of something being the case. Metaphilosophically, constructionism suggests adding conceptual engineering to conceptual analysis as a fundamental method. (shrink)

Semantic information is usually supposed to satisfy the veridicality thesis: p qualifies as semantic information only if p is true. However, what it means for semantic information to be true is often left implicit, with correspondentist interpretations representing the most popular, default option. The article develops an alternative approach, namely a correctness theory of truth (CTT) for semantic information. This is meant as a contribution not only to the philosophy of information but also to the philosophical debate on the nature (...) of truth. After the introduction, in Sect. 2, semantic information is shown to be translatable into propositional semantic information (i). In Sect. 3, i is polarised into a query (Q) and a result (R), qualified by a specific context, a level of abstraction and a purpose. This polarization is normalised in Sect. 4, where [Q + R] is transformed into a Boolean question and its relative yes/no answer [Q + A]. This completes the reduction of the truth of i to the correctness of A. In Sects. 5 and 6, it is argued that (1) A is the correct answer to Q if and only if (2) A correctly saturates Q by verifying and validating it (in the computer science’s sense of verification and validation ); that (2) is the case if and only if (3) [Q + A] generates an adequate model (m) of the relevant system (s) identified by Q; that (3) is the case if and only if (4) m is a proxy of s (in the computer science’s sense of proxy ) and (5) proximal access to m commutes with the distal access to s (in the category theory’s sense of commutation ); and that (5) is the case if and only if (6) reading/writing (accessing, in the computer science’s technical sense of the term) m enables one to read/write (access) s. Sect. 7 provides some further clarifications about CTT, in the light of semantic paradoxes. Section 8 draws a general conclusion about the nature of CTT as a theory for systems designers not just systems users. In the course of the article all technical expressions from computer science are explained. (shrink)

Current dynamic epistemic logics for analyzing effects of informational events often become cumbersome and opaque when common knowledge is added for groups of agents. Still, postconditions involving common knowledge are essential to successful multi-agent communication. We propose new systems that extend the epistemic base language with a new notion of ‘relativized common knowledge’, in such a way that the resulting full dynamic logic of information flow allows for a compositional analysis of all epistemic postconditions via perspicuous ‘reduction axioms’. We also (...) show how such systems can deal with factual alteration, rather than just information change, making them cover a much wider range of realistic events. After a warm-up stage of analyzing logics for public announcements, our main technical results are expressivity and completeness theorems for a much richer logic that we call LCC. This is a dynamic epistemic logic whose static base is propositional dynamic logic (PDL), interpreted epistemically. This system is capable of expressing all model-shifting operations with finite action models, while providing a compositional analysis for a wide range of informational events. This makes LCC a serious candidate for a standard in dynamic epistemic logic, as we illustrate by analyzing some complex communication scenarios, including sending successive emails with both ‘cc’ and ‘bcc’ lines, and other private announcements to subgroups. Our proofs involve standard modal techniques, combined with a new application of Kleene’s theorem on finite automata, as well as new Ehrenfeucht games of model comparison. (shrink)

The analytic/synthetic distinction looks simple. It is a distinction between two different kinds of sentence. Synthetic sentences are true in part because of the way the world is, and in part because of what they mean. Analytic sentences - like all bachelors are unmarried and triangles have three sides - are different. They are true in virtue of meaning, so no matter what the world is like, as long as the sentence means what it does, it will be true. -/- (...) This distinction seems powerful because analytic sentences seem to be knowable in a special way. One can know that all bachelors are unmarried, for example, just by thinking about what it means. But many twentieth-century philosophers, with Quine in the lead, argued that there were no analytic sentences, that the idea of analyticity didn't even make sense, and that the analytic/synthetic distinction was therefore an illusion. Others couldn't see how there could fail to be a distinction, however ingenious the arguments of Quine and his supporters. -/- But since the heyday of the debate, things have changed in the philosophy of language. Tools have been refined, confusions cleared up, and most significantly, many philosophers now accept a view of language - semantic externalism - on which it is possible to see how the distinction could fail. One might be tempted to think that ultimately the distinction has fallen for reasons other than those proposed in the original debate. -/- In Truth in Virtue of Meaning, Gillian Russell argues that it hasn't. Using the tools of contemporary philosophy of language, she outlines a view of analytic sentences which is compatible with semantic externalism and defends that view against the old Quinean arguments. She then goes on to draw out the surprising epistemological consequences of her approach. (shrink)

This work provides an original account of Francis Bacon's conception of natural inquiry. P'erez-Ramos sets Bacon in an epistemological tradition that postulates an intimate relation between objects of cognition and objects of construction, and regards the human knower as, fundamentally, a maker. By exploring the background to this tradition, and contrasting the responses of major philosophers of the 17th century with Bacon's own, the book charts Bacon's contribution to the modern philosophy of science.

The use of “levels of abstraction” in philosophical analysis (levelism) has recently come under attack. In this paper, I argue that a refined version of epistemological levelism should be retained as a fundamental method, called the method of levels of abstraction. After a brief introduction, in section “Some Definitions and Preliminary Examples” the nature and applicability of the epistemological method of levels of abstraction is clarified. In section “A Classic Application of the Method ofion”, the philosophical fruitfulness of the new (...) method is shown by using Kant’s classic discussion of the “antinomies of pure reason” as an example. In section “The Philosophy of the Method of Abstraction”, the method is further specified and supported by distinguishing it from three other forms of “levelism”: (i) levels of organisation; (ii) levels of explanation and (iii) conceptual schemes. In that context, the problems of relativism and antirealism are also briefly addressed. The conclusion discusses some of the work that lies ahead, two potential limitations of the method and some results that have already been obtained by applying the method to some long-standing philosophical problems. (shrink)

One of the open problems in the philosophy of information is whether there is an information logic (IL), different from epistemic (EL) and doxastic logic (DL), which formalises the relation “a is informed that p” (Iap) satisfactorily. In this paper, the problem is solved by arguing that the axiom schemata of the normal modal logic (NML) KTB (also known as B or Br or Brouwer’s system) are well suited to formalise the relation of “being informed”. After having shown that IL (...) can be constructed as an informational reading of KTB, four consequences of a KTB-based IL are explored: information overload; the veridicality thesis (Iap → p); the relation between IL and EL; and the Kp → Bp principle or entailment property, according to which knowledge implies belief. Although these issues are discussed later in the article, they are the motivations behind the development of IL. (shrink)

In this paper we introduce Dynamic Epistemic Logic, which is alogic for reasoning about information change in a multi-agent system. Theinformation structures we use are based on non-well-founded sets, and canbe conceived as bisimulation classes of Kripke models. On these structures,we define a notion of information change that is inspired by UpdateSemantics (Veltman, 1996). We give a sound and complete axiomatization ofthe resulting logic, and we discuss applications to the puzzle of the dirtychildren, and to knowledge programs.

This paper has three goals. The first is to introduce the “knowledge game”, a new, simple and yet powerful tool for analysing some intriguing philosophical questions. The second is to apply the knowledge game as an informative test to discriminate between conscious (human) and conscious-less agents (zombies and robots), depending on which version of the game they can win. And the third is to use a version of the knowledge game to provide an answer to Dretske’s question “how do you (...) know you are not a zombie?”. (shrink)

This paper traces the application of information theory to philosophical problems of mind and meaning from the earliest days of the creation of the mathematical theory of communication. The use of information theory to understand purposive behavior, learning, pattern recognition, and more marked the beginning of the naturalization of mind and meaning. From the inception of information theory, Wiener, Turing, and others began trying to show how to make a mind from informational and computational materials. Over the last 50 years, (...) many philosophers saw different aspects of the naturalization of the mind, though few saw at once all of the pieces of the puzzle that we now know. Starting with Norbert Wiener himself, philosophers and information theorists used concepts from information theory to understand cognition. This paper provides a window on the historical sequence of contributions made to the overall project of naturalizing the mind by philosophers from Shannon, Wiener, and MacKay, to Dennett, Sayre, Dretske, Fodor, and Perry, among others. At some time between 1928 and 1948, American engineers and mathematicians began to talk about `Theory of Information' and `Information Theory,' understanding by these terms approximately and vaguely a theory for which Hartley's `amount of information' is a basic concept. I have been unable to find out when and by whom these names were first used. Hartley himself does not use them nor does he employ the term `Theory of Transmission of Information,' from which the two other shorter terms presumably were derived. It seems that Norbert Wiener and Claude Shannon were using them in the Mid-Forties. (shrink)

This chapter addresses two questions. First, if knowledge is accounted information, how are we supposed (to apply this analysis in order) to understand perceptual knowledge and knowledge by testimony? In the first part of the chapter, I articulate an answer in terms of a re-interpretation of perception and testimony as data providers rather than full-blown cases of knowledge. Second, if perception and testimony are correctly understood as data providers, how are we supposed (to apply this analysis in order) to understand (...) the semantic value of the data provided by such processes? In the second part of the chapter, I argue in favour of a constructionist hypothesis about how data may become meaningful for human cognitive agents through a process of repurposing of natural data/signals. The conclusion of the chapter is that human agents are natural-born data hackers. (shrink)

Pérez-Ramos' study of Baconian science in the New Organon departs sharply from recent interpretation. The single thesis that pervades this book is that the "over-arching ideal guiding Bacon's science" is "maker's knowledge." For Bacon "to know, in brief, means to make". This assertion is itself not made by Bacon, nor does it follow from his statement that "human knowledge and human power meet in one," for power has other forms than making alone. A philosopher who publishes his praise of Machiavelli's (...) realism, and who extends the range of application of his scientia to political knowledge does not restrict the scope of power to "making." Within limits that effectively make Bacon a "philosopher of technology" in a later sense, Pérez-Ramos has given us an original and valuable inquiry. He seeks to give full weight to the Baconian aim to "stake all on the victory of art over nature." This intention has the promise of bringing into a unity the end and the means of Baconian philosophy, the mastery of nature goal and the scientia which is its instrument, a unity not hitherto achieved by Baconian interpreters. (shrink)

A word of warning concerning the aims of this volume is in order. Other wise some readers might be unpleasantly surprised by the fact that two of the chapters of an ostensibly historical book are largely topical rather than historical. They are Chapters 7 and 9, respectively entitled 'Are Logical Truths Analytic?' and 'A Priori Truths and Things-In-Them selves'. Moreover, the history dealt with in Chapter 11 is so recent as to have more critical than antiquarian interest. This mixture of (...) materials may seem all the more surprising as I shall myself criticize (in Chapter I) too facile assimilations of earlier thinkers' concepts and problems to later ones. There is no inconsistency here, it seems to me. The aims of the present volume are historical, and for that very purpose, for the purpose of understanding and evaluating earlier thinkers it is vital to know the conceptual landscape in which they were moving. A crude analogy may be helpful here. No military historian can afford to neglect the topo graphy of the battles he is studying. If he does not know in some detail what kind of pass Thermopylae is or on what sort of ridge the battle of Bussaco was fought, he has no business of discussing these battles, even if this topographical information alone does not yet amount to historical knowledge. (shrink)

... AND PROFITABLE INVENTIONS AND DISCOVERIES; THE BEST STATE OF THAT PROVINCE”: TECHNOLOGY AND CULTURE DURING FRANCIS BACON'S STAY IN FRANCE* Luisa ...

Floridi’s Theory of Strongly Semantic Information posits the Veridicality Thesis. One motivation is that it can serve as a foundation for information-based epistemology being an alternative to the tripartite theory of knowledge. However, the Veridicality thesis is false, if ‘information’ is to play an explanatory role in human cognition. Another motivation is avoiding the so-called Bar-Hillel/Carnap paradox. But this paradox only seems paradoxical, if ‘information’ and ‘informativeness’ are synonymous, logic is a theory of inference, or validity suffices for rational inference; (...) a, b, and c are false. (shrink)

It is often assumed that there is a close connection between Quine's criticism of the analytic/synthetic distinction, in 'Two dogmas of empiricism' and onwards, and his thesis of the indeterminacy of translation, in Word and Object and onwards. Often, the claim that the distinction is unsound (in some way or other) is taken to follow from the indeterminacy thesis, and sometimes the indeterminacy thesis is supported by such a claim. However, a careful scrutiny of the indeterminacy thesis as stated by (...) Quine, and the varieties of the analytic/synthetic distinction, reveals that the two claims are mutually independent. Neither does the claim that the distinction is unsound follow from the indeterminacy thesis, nor that thesis from unsoundness claim, under any of the common interpretations of the analytic/synthetic distinction. (shrink)

Yehoshua Bar-Hillel and Rudolph Carnap’s classical theory of semantic information entails the counterintuitive feature that inconsistent statements convey maximal information. Theories preserving Bar-Hillel and Carnap’s modal intuitions while imposing a veridicality requirement on which statements convey information—such as the theories of Fred Dretske or Luciano Floridi—avoid this commitment, as inconsistent statements are deemed not information-conveying by fiat. This paper produces a pair of paradoxical statements that such “veridical-modal” theories must evaluate as both conveying and not conveying information, although Bar-Hillel and (...) Carnap’s theory accommodates these statements without inconsistency. Moreover, the paradoxes are independently interesting as the mode in which they self-refer bears on their evaluation. (shrink)

Colburn (computer science, U. of Minnesota-Duluth) has a doctorate in philosophy and an advanced degree in computer science; he's worked as a philosophy professor, a computer programmer, and a research scientist in artificial intelligence. Here he discusses the philosophical foundations of artificial intelligence; the new encounter of science and philosophy (logic, models of the mind and of reasoning, epistemology); and the philosophy of computer science (touching on math, abstraction, software, and ontology).

In this paper, we explore the traditional conception of a prioricity as epistemic independence of evidence from sense experience. We investigate the fortunes of the traditional conception in the light of recent challenges by Timothy Williamson. We contend that Williamson’s arguments can be resisted in various ways. En route, we argue that Williamson’s views are not as distant from tradition as they might seem at first glance.

Dynamic Epistemic Logic is the logic of knowledge change. This book provides various logics to support such formal specifications, including proof systems. Concrete examples and epistemic puzzles enliven the exposition. The book also offers exercises with answers. It is suitable for graduate courses in logic. Many examples, exercises, and thorough completeness proofs and expressivity results are included. A companion web page offers slides for lecturers and exams for further practice.

Abstract: According to the Veridicality Thesis, information requires truth. On this view, smoke carries information about there being a fire only if there is a fire, the proposition that the earth has two moons carries information about the earth having two moons only if the earth has two moons, and so on. We reject this Veridicality Thesis. We argue that the main notions of information used in cognitive science and computer science allow A to have information about the obtaining of (...) p even when p is false. (shrink)

The distinction between knowledge-how and knowledge-that has long been debated in the epistemological literature. This distinction can, arguably, be better understood in terms of a more fundamental distinction between information-how and information-that. Information-how is prescriptive and informs a cognitive agent about which action can be performed to achieve a particular outcome. Information-that is descriptive and informs the agent about events, objects, and states of affairs in the world. Since the latter has received more attention in the epistemological literature, this article (...) focuses on the former. I offer a new account of information-how that answers the question, ‘When do data qualify as information-how?’. (shrink)

This paper contributes to the current debate on the nature of semantic information by offering a semantic argument in favour of the veridical thesis according to which p counts as information only if p is true. In the course of the analysis, the paper reviews some basic principles and requirements for any theory of semantic information.