Starting from the sixties of the past century theory change has become a main concern of philosophy of science. Two of the best known formal accounts of theory change are the post-Popperian theories of verisimilitude (PPV for short) and the AGM theory of belief change (AGM for short). In this paper, we will investigate the conceptual relations between PPV and AGM and, in particular, we will ask whether the AGM rules for theory change are effective means for approaching the truth, (...) i.e., for achieving the cognitive aim of science pointed out by PPV. First, the key ideas of PPV and AGM and their application to a particular kind of propositional theories - the so called "conjunctive propositions" - will be illustrated. Afterwards, we will prove that, as far as conjunctive propositions are concerned, AGM belief change is an effective tool for approaching the truth. (shrink)

In this paper we give some formal examples of ideas developed by Penco in two papers on the tension inside Frege's notion of sense (see Penco 2003). The paper attempts to compose the tension between semantic and cognitive aspects of sense, through the idea of sense as proof or procedure – not as an alternative to the idea of sense as truth condition, but as complementary to it (as it happens sometimes in the old tradition of procedural semantics).

In this paper, we will discuss what is called the “Manifestation Challenge” to semantic realism, which was originally developed by Michael Dummett and has been further refined by Crispin Wright. According to this challenge, semantic realism has to meet the requirement that knowledge of meaning must be publically manifested in linguistic behaviour. In this regard, we will introduce and evaluate John McDowell’s response to this anti-realistic challenge, which was put forward to show that the challenge cannot undermine realism. According to (...) McDowell, knowledge of undecidable sentences’ truth-conditions can be properly manifested in our ordinary practice of asserting such sentences under certain circumstances, and any further requirement will be redundant. Wright’s further objection to McDowell’s response will be also discussed and it will be argued that this objection fails to raise any serious problem for McDowell’s response and that it is an implausible objection in general. (shrink)

The main aim of this article is to pose and consider the following question: Does the reasoning that led to Kripkenstein’s sceptical paradox undermine all versions of materialism, including nonreductive materialism? First, I present other versions of materialism in the philosophy of mind. Then I point out that, according to nonreductive materialists, one can neither define mental properties in terms of physical properties nor derive psycho‑physical laws from the laws of physics. The presently‑understood thesis of materialism is confined by the (...) following claim: the same distribution of physical properties entails the same distribution of mental properties. In other words, the mental properties supervene upon physical properties. This account then leads to the following formulation of the main question: Assuming that Kripkenstein is right, do mental properties supervene upon physical properties? Taking into account that answering this question requires a discussion of the notions of supervenience and Kripkenstein’s paradox, I devote two parts of my paper to these topics. The conclusion which I reach is as follows: If the reasoning that led to Kripkenstein’s paradox is correct, mental properties can only globally supervene upon physical properties, and consequently no version of materialism can be empirically justified. (shrink)

Thinking and using a language are two different but similar activities. Thinking about thinking and thinking about language use have been two major strands in the history of philosophy. One of the principal similarities is that they are both rational activities. As a result, the ability to think and the ability to use a language require being able to recognise and respond to reasons. However, there is a further feature of these activities: we humans are able to have explicit knowledge (...) of how those activities work and what is done by performances in those activities. Thus, theorists face at least two constraints: 1. An account of a rational activity must be compatible with the possibility of agents engaging in that activity. 2. Having described an activity, it must be possible to have knowledge of an activity which is correctly described like that. There are a variety of accounts of how thinking works and how using a language works, and further variation in accounts of what is involved in explicit understanding of particular performances. These accounts can be distinguished by their views of the nature of the reasons that govern performances in that activity and by their views of the way a description of the activity relates to the way the activity proceeds. I argue that any description of thinking or language use requires showing how the truth conditions of thoughts/sentences are determined, and how the truth values of thoughts/sentences affects the way the activity proceeds. I then argue that in order to have explicit knowledge of what we do, truth has to be a substantial evaluative property of uses of language, and furthermore a truth conditional theory of meaning has to be taken as the description of the rationality of using a language. The big result is that, because in understanding language we understand truth, the philosophy of language is first philosophy. (shrink)

La rinascita negli ultimi decenni di un nutrito dibattito intorno alla nozione di analiticità dopo le critiche a suo tempo mosse da Quine alla batteria di nozioni utilizzate da Rudolf Carnap (ad esempio, postulati di significato, regole semantiche, definizioni implicite, convenzioni e stipulazioni esplicite) prende le mosse da una riflessione critica sulle argomentazioni di Quine e tenta, da un lato, di approfondire meglio il legame fra analiticità e conoscenza a priori, e, dall’altro, di capire meglio il ruolo che la definizione (...) può svolgere nella costituzione del significato e nella formulazione di verità concettuali. Questa nuova concezione è detta “epistemica” ed ha fra i suoi più autorevoli fautori Crispin Wright, Bob Hale e Paul Boghossian. Boghossian, al pari di molti filosofi critici della nuova concezione epistemica, come Timothy Williamson, conviene però con Quine nel sostenere che gli enunciati analitici hanno portata fattuale e vertono anch’essi sul mondo, oltre che sul linguaggio. Anche per questa ragione essi possono rendere possibile una genuina estensione delle nostre conoscenze. Tuttavia una seconda linea di obiezioni facenti capo dapprima a Paul Horwich, e in seguito agli stessi Wright e Hale, mette in evidenza rispettivamente due difficoltà corrispondenti alle questioni dell’arroganza e dell’accettazione. In questa discussione una parte importante è svolta dalla ripresa e della discussione del condizionale di Carnap, impiegato per rendere conto del ruolo che i termini teorici svolgono nel quadro dell’intera teoria cui appartengono, senza con ciò sposare le conseguenze dell’olismo quineano. La tesi centrale che questo lavoro cerca di rendere plausibile è che una lettura attenta degli ultimi scritti di Carnap mostri come il carattere aperto che egli attribuisce ai termini teorici in ragione, sia dello loro intrinseca indeterminatezza, sia delle revisioni imposte dalle scoperte scientifiche, è perfettamente compatibile con la fattorizzazione del contenuto di una teoria scientifica data in una parte linguistica, il condizionale di Carnap, riguardante la costituzione del significato di un certo termine teorico, e nella sua controparte empirica, che consente di registrare l’impatto dell’esperienza sulla teoria in questione. Se praticabile, questa concezione può a buon diritto entrare nel novero delle teorie epistemiche dell’analiticità, senza accampare alcuna pretesa di far rivivere i fasti della conoscenza a priori classica. (shrink)

We outline an intuitionistic view of knowledge which maintains the original Brouwer–Heyting–Kolmogorov semantics for intuitionism and is consistent with the well-known approach that intuitionistic knowledge be regarded as the result of verification. We argue that on this view coreflectionA→KAis valid and the factivity of knowledge holds in the formKA→ ¬¬A‘known propositions cannot be false’.We show that the traditional form of factivityKA→Ais a distinctly classical principle which, liketertium non datur A∨ ¬A, does not hold intuitionistically, but, along with the whole of (...) classical epistemic logic, is intuitionistically valid in its double negation form ¬¬(KA¬A).Within the intuitionistic epistemic framework the knowability paradox is resolved in a constructive manner. We argue that this paradox is the result of an unwarranted classical reading of constructive principles and as such does not have the consequences for constructive foundations traditionally attributed it. (shrink)

Justification Logic provides an axiomatic description of justifications and delegates the question of their nature to semantics. In this note, we address the conceptual issue of the logical type of justifications: we argue that justifications in the logical setting are naturally interpreted as sets of formulas which leads to a class of epistemic models that we call modular models . We show that Fitting models for Justification Logic naturally encode modular models and can be regarded as convenient pre-models of the (...) former. (shrink)

We construct an extension P of the standard language of classical propositional logic by adjoining to the alphabet of a new category of logical-pragmatic signs. The well formed formulas of are calledradical formulas (rfs) of P;rfs preceded by theassertion sign constituteelementary assertive formulas of P, which can be connected together by means of thepragmatic connectives N, K, A, C, E, so as to obtain the set of all theassertive formulas (afs). Everyrf of P is endowed with atruth value defined classically, (...) and everyaf is endowed with ajustification value, defined in terms of the intuitive notion of proof and depending on the truth values of its radical subformulas. In this framework, we define the notion ofpragmatic validity in P and yield a list of criteria of pragmatic validity which hold under the assumption that only classical metalinguistic procedures of proof be accepted. We translate the classical propositional calculus (CPC) and the intuitionistic propositional calculus (IPC) into the assertive part of P and show that this translation allows us to interpret Intuitionistic Logic as an axiomatic theory of the constructive proof concept rather than an alternative to Classical Logic. Finally, we show that our framework provides a suitable background for discussing classical problems in the philosophy of logic. (shrink)

I argue that the standard anti-realist argument from manifestability to intuitionistic logic is either unsound or invalid. Strong interpretations of the manifestability of understanding are falsified by the existence of blindspots for knowledge. Weaker interpretations are either too weak, or gerrymandered and ad hoc. Either way, they present no threat to classical logic.

This book is a synthesis of more than three decades of research into the concept of time and its semiotic nature. If traditional philosophy – and philosophy of time should be no exception – in the shadow of advancing biology can be said to have reached an impasse, one important reason for this, in harmony with Wittgenstein’s vision, appears to have been its lack of appropriate tools for explicating language. The present theory of time proceeds, accordingly, from the exploration of (...) temporal expressions in language as an evolutionary fact. It derives in a hypothetical, coherent feedback process of hierarchically ordered distinctions the semantics of time from its biologically dictated perceptual and cognitive-pragmatic origins. The corresponding abductive-regulative model is anchored in the assumption of biological rhythmization as the very foundation of perception and mental/physical action. Understood to originate in space and spatial perspective, time reveals itself as an instrument for temporal perspective on motion (events and situations) in a process of analysis, i.e., discontinuation of chaos made divisible and continuous by the rhythmical screen. Whereas traditional philosophy of time paid attention almost exclusively to the temporal category of tense, the biopragmatic model sees strong evidence in the perspectival nature of time for ascribing the decisive, and probably universal, role in temporal analysis to the linguistic category of aspect. Aspect may, according to the present findings, be assumed to partake already of change-of-state and cause-effect analysis without which man’s adaptation to new situations – and precondition for survival – would be inconceivable. The proposed model of space/time cognition, inspired by Hegelian dialectics, Heidegger-Gadamer’s hermeneutic circle and Peircean logic, makes Kantian a priori superfluous and liberates time from its enigmatic appearance. For the first time in temporal studies it thus appears possible to derive hypothetically linguistic expressions of time all the way from pretemporal, homogeneous continuity effected by biological rhythmization, via pretemporal metonymic (Gestalt), chunk-wise partitioning – as a general precondition for the perception and, based on primary metaphorization, the cognition of things, space and motion – to temporal analysis/discontinuation proper, primarily by aspectual perspective, and the subsequent synthesized, heterogeneous continuity of temporally ordered events. The conception of time, so disastrous for modern temporal logic, i.e., as moving object assigned extension, divisible continuity (‛linearity’) and direction, can be shown to have emerged as a result of secondary metaphorization. (shrink)