I develop a basic theory of content within the framework of truthmaker semantics and, in the second part, consider some of the applications to subject matter, common content, logical subtraction and ground.

The intuitive notion of a binary relation on information-bearers, comparingthem with respect to their closeness to the available information, is oftenconstrued in terms of comparing their symmetric difference with, orcompositional similarity to, the available information. This happens forinstance in some treatments of verisimilitude. We expound an abstractmathematical rendering of the relevant data-dependent relation in theframework of Boolean algebras. For every element t of a Boolean algebra B we construct the t-modulated Boolean algebra Btin which the order relation represents `is at (...) most as compatible with t as' or `is at best as similar to t as'. In the case of Lindenbaum-Tarskialgebras, t expresses the available information, and the compatibilityrelation turns out to be an entwinement of inferential and conjecturalrelations. It is just classical entailment when no information is available(i.e., when t is logically true) and becomes more boldly abductive themore information is available. The rich algebraic structures of a Boolean algebra –- including its Boolean group structures –- play a significant role in this combination of deduction and abduction and also induce cautious anddaring variants of the compatibility relation. Links with the literature onverisimilitude, abduction, and related topics are indicated. (shrink)

Of two false theories, One can be, Intuitively, Closer to the truth than the other. The purpose of the article is to propose a rigorous explication of this intuitive notion.

I provide a truthmaker semantics for Angell’s system of analytic implication and establish completeness.

Aboutness has been studied from any number of angles. Brentano made it the defining feature of the mental. Phenomenologists try to pin down the aboutness-features of particular mental states. Materialists sometimes claim to have grounded aboutness in natural regularities. Attempts have even been made, in library science and information theory, to operationalize the notion. But it has played no real role in philosophical semantics. This is surprising; sentences have aboutness-properties if anything does. Aboutness is the first book to examine through (...) a philosophical lens the role of subject matter in meaning. A long-standing tradition sees meaning as truth-conditions, to be specified by listing the scenarios in which a sentence is true. Nothing is said about the principle of selection--about what in a scenario gets it onto the list. Subject matter is the missing link here. A sentence is true because of how matters stand where its subject matter is concerned. Stephen Yablo maintains that this is not just a feature of subject matter, but its essence. One indicates what a sentence is about by mapping out logical space according to its changing ways of being true or false. The notion of content that results--directed content--is brought to bear on a range of philosophical topics, including ontology, verisimilitude, knowledge, loose talk, assertive content, and philosophical methodology. Written by one of today's leading philosophers, Aboutness represents a major advance in semantics and the philosophy of language. (shrink)

Surprisingly, modified versions of the confirmation theory (Carnap and Hempel) and truth approximation theory (Popper) turn out to be smoothly sythesizable. The glue between the two appears to be the instrumentalist methodology, rather than that of the falsificationalist. The instrumentalist methodology, used in the separate, comparative evaluation of theories in terms of their successes and problems (hence, even if already falsified), provides in theory and practice the straight road to short-term empirical progress in science ( à la Laudan). It is (...) also argued that such progress is also functional for all kinds of truth approximation: observational, referential, and theoretical. This sheds new light on the long-term dynamics of science and hence on the relation between the main epistemological positions, viz., instrumentalism (Toulmin, Laudan), constructive empiricism (Van Fraassen), referential realism (Hacking, Cartwright), and theory realism of a non-essentialist nature (constructive realism à la Popper). Readership: Open minded philosophers and scientists. The book explains and justifies the scientist's intuition that the debate among philosophers about instrumentalism and realism has almost no practical consequences. (shrink)

What does it take for one proposition to be closer to the truth than another. In this, the first published monograph on the topic, Oddie develops a comprehensive theory that takes the likeness in truthlikeness seriously.

I propose a new semantics for intuitionistic logic, which is a cross between the construction-oriented semantics of Brouwer-Heyting-Kolmogorov and the condition-oriented semantics of Kripke. The new semantics shows how there might be a common semantical underpinning for intuitionistic and classical logic and how intuitionistic logic might thereby be tied to a realist conception of the relationship between language and the world.

I present a puzzle concerning counterfactual reasoning and argue that it should be solved by giving up the principle of substitution for logical equivalents.

In order to perfectly describe the world, it is not enough to speak truly. One must also use the right concepts - including the right logical concepts. One must use concepts that "carve at the joints", that give the world's "structure". There is an objectively correct way to "write the book of the world". Much of metaphysics, as traditionally conceived, is about the fundamental nature of reality; in the present terms, this is about the world's structure. Metametaphysics - inquiry into (...) the status of metaphysical questions - turns on structure. The question of whether ontological, causal, or modal questions are "substantive" is in large part a question of whether the world has ontological, causal, and modal structure - whether quantifiers, causal relations, and modal operators carve at the joints. (shrink)

The article offers a rigorous explication of the intuitive notion of verisimilitude, I.E., Of the distance of a theory from the truth. The proposal is defended against charges of material inadequacy made by popper, Niniluoto, And miller.

2 Popper's Logical Definition of Verisimilitude. 3 Popper's Probabilistic Definition of Verisimilitude. 4 Conclusion.

Recent interest in the problem of verisimilitude stemmed originally from Popper's desire to provide a non-inductive criterion of merit that will select between two false theories) But the problem has also been taken up by others who are not committed to Popper's anti-inductivism. Indeed Ilkka Niiniluoto has argued that the estimated degree of truthlikeness of a generalisation g which is compatible with evidence e can be equated with the inductive probability of g on e, wherever g is a constituent in (...) Hintikka's sense. It might therefore be worth while to approach the problem afresh, in order to determine quite generally whether a measure of verisimilitude is what is principally needed for the evaluation of scientific progress. I shall argue that it is not. (shrink)

A number of different theories of truthlikeness have been proposed, but most can be classified into one of two different main programmes: the probability-content programme and the likeness programme.1 In Brink and Heidema [1987] we are offered a further proposal, with the attraction of some novelty. I argue that while the heuristic path taken by the authors is rather remote from what they call ‘the well-worn paths’,2 in fact their point of arrival is rather closer to existing proposals within the (...) likeness approach than might at first appear. It is the purpose of this note to outline the logical connections and to assess the reasons which have been offered in favour of the new proposal. (shrink)

relative to the actual world) of a propositional theory are defined. A theory is ‘closer to the truth’ the logically stronger its positive content and the logically weaker its negative content. This proposal delivers the same verisimilar preordering of theories that has been defined by Brink and Heidema as a ‘power ordering’. The preordering may be collapsed to a partial ordering and then embedded into a complete distributive lattice. The preordering may also be refined to a partial ordering by employing (...) the ‘convex content’ and the ‘non-convex content’ of each theory. Philosophical implications and historical relations are discussed. (shrink)

This paper is an attempt to apply the truthmaker approach, recently developed by a number of authors, to the problem of providing an adequate formulation of the is–ought gap. I begin by setting up the problem and criticizing some other accounts of how the problem should be stated; I then introduce the basic apparatus of truth-making and show how it may be extended to include both descriptive and normative truth-makers; I next consider how the gap principle should be formulated, attempting (...) to deal as systematically as possible with the ‘harmless’ counter-examples; I also consider the relationship between the gap principle and various other doctrines concerning the separation between the normative and descriptive realms; and I conclude this part of the paper with some general remarks in favor of adopting the truth-maker approach over some of the alternative approaches. The paper concludes with a formal appendix, which gives precise expression to some of claims made in the previous informal part of the paper. (shrink)

INTRODUCTION When Karl Popper published in' his definition of closer-to-the- truth this was an important intellectual event, but not a shocking one. ...

L. J. Cohen [1] has recently argued that there is an important concept which is not adequately captured by the recent theories of truthlikeness. Cohen points out that, instead of truth about the actual world, much of science pursues \physically necessary truth", and he concludes that \it is legisimilitude that much of science seeks, not verisimilitude". This point is well made, since the earlier accounts of truthlikeness have not paid attention to the important distinction between lawlike and accidental generalizations.

The expansion or revision of false theories by true evidence does not always increase their verisimilitude. After a comparison of different notions of verisimilitude the relation between verisimilitude and belief expansion or revision is investigated within the framework of the relevant element account. We are able to find certain interesting conditions under which both the expansion and the revision of theories by true evidence is guaranteed to increase their verisimilitude.

Starting with Popper, philosophers and logicians have proposed different accounts of verisimilitude or truthlikeness. One way of classifying such accounts is to distinguish between “conjunctive” and “disjunctive” ones. In this paper, we focus on our own “basic feature” approach to verisimilitude, which naturally belongs to the conjunctive family. We start by surveying the landscape of conjunctive accounts; then, we introduce two new measures of verisimilitude and discuss their properties; finally, we conclude by hinting at some surprising relations between our conjunctive (...) approach and a disjunctive account of verisimilitude widely discussed in the literature. (shrink)

Theories of verisimilitude have routinely been classified into two rival camps—the content approach and the likeness approach—and these appear to be motivated by very different sets of data and principles. The question thus naturally arises as to whether these approaches can be fruitfully combined. Recently Zwart and Franssen (Synthese 158(1):75–92, 2007) have offered precise analyses of the content and likeness approaches, and shown that given these analyses any attempt to meld content and likeness orderings violates some basic desiderata. Unfortunately their (...) characterizations of the approaches do not embrace the paradigm examples of those approaches. I offer somewhat different characterizations of these two approaches, as well as of the consequence approach (Schurz and Weingartner (Synthese 172(3):415–436, 2010) which happily embrace their respective paradigms. Finally I prove that the three approaches are indeed compatible, but only just, and that the cost of combining them is too high. Any account which combines the strictures of what I call the strong likeness approach with the demands of either the content or the consequence approach suffers from precisely the same defect as Popper’s—namely, it entails the trivialization of truthlikeness. The downside of eschewing the strong likeness constraints and embracing the content constraints alone is the underdetermination of the concept of truthlikeness. (shrink)

In this article I give a naturalistic-cum-formal analysis of the relation between beauty, empirical success, and truth. The analysis is based on the one hand on a hypothetical variant of the so-called 'mere-exposure effect' which has been more or less established in experimental psychology regarding exposure-affect relationships in general and aesthetic appreciation in particular (Zajonc 1968; Temme 1983; Bornstein 1989; (Ye 2000). On the other hand it is based on the formal theory of truthlikeness and truth approximation as presented in (...) my From Instrumentalism to Constructive Realism (2000). The analysis supports the findings of James McAllister in his beautiful Beauty and Revolutiorl in Science (1996), by explaining and justifying them. First, scientists are essentially right in regarding aesthetic criteria useful for empirical progress and even for truth approximation, provided they conceive of them as less hard than empirical criteria. Second, the aesthetic criteria of the time, the 'aesthetic canon', may well be based on 'aesthetic induction' regarding nonempirical features of paradigms of successful theories which scientists have come to appreciate as beautiful. Third, aesthetic criteria can play a crucial, schismatic role in scientific revolutions. Since they may well be wrong, they may, in the hands of aesthetic conservatives, retard empirical progress and hence truth approximation, but this does not happen in the hands of aesthetically flexible, 'revolutionary' scientists. (shrink)

Popper’s original definition of verisimilitude in terms of comparisons of truth content and falsity content has known counter-examples. More complicated approaches have met with mixed success. This paper uses a new account of logical content to develop a definition of verisimilitude that is close to Popper’s original account. It is claimed that Popper’s mistake was to couch his account of truth and falsity content in terms of true and false consequences. Comparison to a similar approach by Schurz and Wiengartner show (...) certain advantages of this new approach. (shrink)

It is shown that certain natural constraints trivialize the concept of partial content and it is suggested, in the light of this difficulty, that the principle that partial content is preserved under the substitution of logical equivalents should be given up.

The intuitive notion of a binary relation on information-bearers, comparingthem with respect to their closeness to the available information, is oftenconstrued in terms of comparing their symmetric difference with, orcompositional similarity to, the available information. This happens forinstance in some treatments of verisimilitude. We expound an abstractmathematical rendering of the relevant data-dependent relation in theframework of Boolean algebras. For every element t of a Boolean algebra B we construct the t-modulated Boolean algebra Btin which the order relation represents `is at (...) most as compatible with t as'' or `is at best as similar to t as''. In the case of Lindenbaum-Tarskialgebras, t expresses the available information, and the compatibilityrelation turns out to be an entwinement of inferential and conjecturalrelations. It is just classical entailment when no information is available(i.e., when t is logically true) and becomes more boldly abductive themore information is available. The rich algebraic structures of a Boolean algebra –- including its Boolean group structures –- play a significant role in this combination of deduction and abduction and also induce cautious anddaring variants of the compatibility relation. Links with the literature onverisimilitude, abduction, and related topics are indicated. (shrink)

The recent theories of truthlikeness have not paid attention to the distinction between lawlike and accidental generalizations. L.J. Cohen has expressed this by saying that science aims at legisimilitude rather than verisimilitude. G. Oddie has given a reply to Cohen by defining the notion of legisimilitude in terms of higher-order logics. This paper gives a different reply to Cohen by treating laws as physically necessary generalizations and by defining the notion of legisimilitude as closeness to a suitably chosen lawlike sentence.