Jaroslav Peregrin

Když jsem v roce 1992 začínal na filosofické fakultě UK přednášet teorii sémantiky, cítil jsem intenzivní potřebu poskytnout studentům nějaký učební text. O překotném vývoji tohoto interdisciplinárního oboru, který odstartovalo v sedmdesátých letech úspěšné “zkřížení logiky s lingvistikou” Richardem Montaguem a dalšími a který se nezpomalil dodnes, totiž v češtině neexistovaly prakticky žádné zprávy (s čestnou výjimkou přístupu tzv. transparentní intenzionální logiky, který byl dílem českého emigranta Pavla Tichého a o kterém u nás psal Pavel Materna). Přehledové publikace, jaké jsou potřeba pro někoho, kdo se chce v dané problematice zorientovat, se ovšem v té době i po světě teprve začínaly objevovat: v roce 1990 vyšla kniha An Introduction to Semantics Gennara Chierchii a Sally McConell-Ginnetové a v roce 1991 vydala skupina holandských logiků pod kolektivním pseudonymem L.T.F. Gamut dvousvazkovou knihu Language and Meaning. Za této situace jsem se pokusil co nejrychleji sepsat učební text, který by moji studenti i jiní zájemci o sémantiku mohli použít; a protože o jeho vydání paradoxně projevila větší zájem filosofická fakulta Masarykovy univerzity v Brně (kde jsem já osobně nikdy neučil; ale zájem o sémantiku tam neúnavně podněcoval a vydání mého textu tam zprostředkoval kolega Materna) než filosofická fakulta mojí domovské Karlovy univerzity, vyšel tento text v Brně, a to pod názvem Úvod do teoretické sémantiky.

Logic is usually considered to be the study of logical consequence – of the most basic laws governing how a statement’s truth depends on the truth of other statements. Some of the pioneers of modern formal logic, notably Hilbert and Carnap, assumed that the only way to get hold of the relation of consequence was to reconstruct it as a relation of inference within a formal system built upon explicit inferential rules. Even Alfred Tarski in 1930 seemed to foresee no kind of consequence other than one induced by a set of inference rules: "Let A be an arbitrary set of sentences of a particular discipline. With the help of certain operations, the so-called rules of inference , new sentences are derived from the set A , called the consequences of the set A . To establish these rules of inference, and with their help to define exactly the concept of consequence, is again a task of special metadisciplines; in the usual terminology of set theory the schema of such definition can be formulated as follows: The set of all consequences of the set A is the intersection of all sets which contain the set A and are closed under the given rules of inference." (p. 63) Thereby also the concept of truth came to be reconstructed as inferability from the empty set of premises. (More precisely, this holds only for non-empirical, necessary truth; but of course logic never set itself the task of studying empirical truth.) From this viewpoint, logic came to look as the enterprise of explication of consequence in terms of inference

Vuvodnim rocniku ORGANONu Pavel Cmorej ve svych @@piton lch z logicjce syntaxe predvadel, jak je prirozeny jazyk mozne nahlizet prismatem 'standardni' logiky. Historicky ovsem neexistuje jedna logika,ale ruzne logicke systemy, ktere spolu castecne soupeii (tak jako treba klasicka a intuicionisticka logika), castecne jeden druhy rozsiruji (Iako treba klasicky vyrokovy a klasicky predikatovy pocet) ci se navzajem doplnuji (Iako napriklad modalni a temporalni logika). To co je v logice obecne prijimano za standard, je fakticky vysledkem interakce a soutezeni ruznych neustale vznikajicich systemu

The entire development of modern logic is characterized by various forms of confrontation of what has come to be called proof theory with what has earned the label of model theory. For a long time the widely accepted view was that while model theory captures directly what logical formalisms are about, proof theory is merely our technical means of getting some incomplete grip on this; but in recent decades the situation has altered. Not only did proof theory expand into new realms, generalizing the concept of proof in various directions; many philosophers also realized that meaning may be seen as primarily consisting in certain rules rather than in language-world links. However, the possibility of construing meaning as an inferential role is often seen as essentially compromised by the limits of prooftheoretical means. The aim of this paper is to sort out the cluster of problems besetting logical inferentialism by disentangling and clarifying one of them, namely determining the power of various inferential frameworks as measured by that of explicitly semantic ones

In his “Making it Explicit”,1 Robert Brandom set up a new philosophical paradigm, concentrating especially on the link between language and the world, but extendable (in the way familiar from the dawn of the linguistic turn) to the rest of philosophy. He views modern philosophy in terms of the tension between “representationalist” and “inferentialist” approaches to language (which, according to him, also underlies the much more commonly cited struggle between empiricism and rationalism); and elaborating on the ideas of his teacher Wilfrid Sellars he develops a distinctive kind of inferentialist framework.

This book offers a comprehensive account of logic that addresses fundamental issues concerning the nature and foundations of the discipline. The authors claim that these foundations can not only be established without the need for strong metaphysical assumptions, but also without hypostasizing logical forms as specific entities. They present a systematic argument that the primary subject matter of logic is our linguistic interaction rather than our private reasoning and it is thus misleading to see logic as revealing "the laws of thought". In this sense, fundamental logical laws are implicit to our "language games" and are thus more similar to social norms than to the laws of nature. Peregrin and Svoboda also show that logical theories, despite the fact that they rely on rules implicit to our actual linguistic practice, firm up these rules and make them explicit. By carefully scrutinizing the project of logical analysis, the authors demonstrate that logical rules can be best seen as products of the so called reflective equilibrium. They suggest that we can profit from viewing languages as "inferential landscapes" and logicians as "geographers" who map them and try to pave safe routes through them. This book is an essential resource for scholars and researchers engaged with the foundations of logical theories and the philosophy of language.

The paper addresses foundational questions concerning the dynamic semantics of natural language based on dynamic logic of the Groenendijko-Stokhofian kind. Discussing a series of model calculi of increasing complexity, it shows in detail how the usual semantics of dynamic logic can be seen as emerging from the account for certain inferential patterns of natural language, namely those governing anaphora. In this way, the current ‘dynamic turn’ of logic is argued to be reasonably seen not as the product of changing the focus of logic from the relation of entailment to „a structure of human cognitive action“ (van Benthem), but rather as merely another step in our long-term effort to master more and more inferential patterns.

The contemporary popularity of the prefix post has found its expression also in the realm of analytic philosophy - there arises something which has come to be called postanalytic philosophy. We put forward that this branch of the analytic movement, germinating in the writings of the late Ludwig Wittgenstein, of Wllard Van Orman Quine and Willfrid Sellars, and coming to fill blossom with Nelson Goodman, Donald Davidson, Hilary Putnam and Richard Rorty, springs first and foremost from the repudiation of the doctrine of logical atomism as entertained by Bertrand Russell and the early Wittgenstein. The dismantling of this doctrine means especially the denial of the following four points: the atomistic character of language; the sharp boundary between analytic and contingent statements; the sharp boundary between ġiven\' and ínferred\' knowledge; and also the essential cummulativity of knowledge. Postanalytic philosophy is thus essentially holistic; and we put forward that in fact postanalytic philosophy equals analytic philosophy minus logical atomism

It is a common wisdom that whereas consequence or entailment is a semantic concept, provability is a syntactic concept. However, what exactly does this mean? What is provability? In the traditional, intuitive sense, to prove something is to demonstrate its truth, and indeed the Latin word for proof is demonstratio. Hence in this sense, we cannot prove something unless it is true. Now in the course of his well known proof of the incompleteness of arithmetic, Gödel showed that provability within the axiomatic system of Peano arithmetic (PA) can be reconstructed as a number-theoretic predicate Pr and he showed that within the system there exists a statement G so that..

In considering the very possibility of deviant logic, we face the following question: what makes us see an operator of one logical system as a deviant version of an operator of another system? Why not see it simply as a different operator? Why do we see, say, intuitionist implication as an operator 'competing' with classical implication? Is it only because both happen to be called implications?1 It is clear that if we want to make cross-systemic comparisons, we need an 'Archimedean point' external to the systems compared. Some logicians and philosophers, including Quine (1986), come close to saying that no such Archimedean point is available, and hence that there can be no deviant logics, for if two operators are governed by different axioms, then they are simply two different operators (or, if you prefer, operators with different meanings). From this viewpoint, intuitionist implication is no less different from classical implication than, say, intuitionist or classical conjunction. This conclusion is indeed plausible if we consider logical calculi simply as algebraic structures2; however, things are different if we see them as a means of accounting for something that is already 'there' before we establish the structures and is to be explicated by them. From such a perspective, two operators of different systems may be variants of the same operator in virtue of the fact that they are both means of capturing the same pretheoretical item. What might these items be? Sometimes it seems that logicians tacitly assume that there are some mythical archetypes of implication, conjunction etc., located somewhere in some Platonic heaven or somehow underlying the a priori structures of our mind, which logic tries to capture (for better or worse). However, when it comes to the comparison of the concrete outcomes of our logical efforts, say the classical and the intuitionist implications with the archetypal Implication, the latter can never be materialized so distinctly as to be of any help. A more constructive proposal is that the operators are related to elements or constructions of our language..

The concept ofsemantic interpretation is a source of chronic confusion: the introduction of a notion ofinterpretation can be the result of several quite different kinds of considerations.Interpretation can be understood in at least three ways: as a process of dis-abstraction of formulas, as technical tool for the sake of characterizing truth, or as a reconstruction of meaning-assignment. However essentially different these motifs are and however properly they must be kept apart, these can all be brought to one and the same notion of interpretation: to the notion of a compositional evaluation of expressions inducing a possible distribution of truth values among statements.

Though, at first sight, logical formalization of natural language sentences and arguments might look like an unproblematic enterprise, the criteria of its success are far from clear and, surprisingly, there have only been a few attempts at making them explicit. This paper provides a picture of the enterprise of logical formalization that does not conceive of it as a kind of translation from one language (a natural one) into another language (a logical one), but rather as a construction of a 'map' of (a piece of) the 'inferential landscape' of the natural language. The criteria that appear to govern the enterprise are labeled as those of reliability, ambitiousness, transparency and parsimony. These criteria, it is argued, do not provide for an excavation of a ready-made logical structure, but rather help us achieve a "reflective equilibrium" between the normative authority of logic and the answerability of logic to a natural language

Knihu Kritika depolitizovaného rozumu (podtitul Úvahy (nejen) o nové normalizaci, Václav Bělohradský a kol., Grimmus, Všeň 2010) jsem si kupoval s vědomím, že s její- mi autory se asi nebudu ve všem shodovat, nicméně také s přesvědčením, že problém, na který poukazuje její název, je skutečně závažný, a s nadějí, že se o něm třeba dozvím něco z úhlu pohledu, který mi není vlastní, a tak se mi podaří ho nahlédnout plastičtěji. Bohužel jsem zjistil, že název knihy je pouze krycí; že nejde o boj s depolitizací rozumu, ale naopak o zčásti otevřený a zčásti partyzánský boj proti skutečné politizaci, tj. proti demokratické- mu prostředí, ve kterém se otázky zá- kladního směřování společnosti mohly stát předmětem politických diskuzí a politických střetů, ve jménu absolutizace určitých velice konkrétních, pokud ne pří- mo politických, pak ideologických názorů. Jak říkám, jsem přesvědčený, že problém depolitizace rozumu tu skutečně je. Lidé, zdá se mi, skutečně mají čím dál více pocit, že všechna rozhodnutí jsou na nějakých těch odbornících, jimž do toho nejenom není potřeba mluvit, ale ani by se jim do toho mluvit nemělo. Máme stát zadlužovat? To přece musejí říci ekonomové. Mají se zakazovat politické strany? To my nevíme, ale vědět to musejí politologové či sociologové. Je potrat vražda, nebo medicínský zákrok? To by nám měli říci biologové, filozofové nebo bůhvíkdo, ale hlavně někdo, kdo to dokáže vyčíst z příslušných faktů.

Saul Kripke ’s book Naming and Necessity (which first appeared in 1972 as a paper within a volume on natural language semantics1) is felt, by many linguists and philosophers, as a milestone of the semantic analysis of natural language. Prior to it, many semanticists took for granted that the meaning of any expression must be a two-level matter, consisting of something of the kind of what Frege called Sinn and Bedeutung or what Carnap christened as intension and extension. The first of the components is what the speaker knows when she understands the expression (and the knowledge of which is independent of any knowledge of facts external to the language in question), while the second amounts to some kind of chunk of the real world which gets denoted or referred to by the expression. Thus, the intension of the king of France is what you get to know as soon as you come to understand the phrase, and the extension is what (if anything) happens to be picked out by the intension in the actual world in the actual moment. This is to say that an expression gets to into the contact with its extension only via the intension (which we can imagine also as a kind of a criterion for picking up the thing). Intension, then, is what amounts to the meaning of the expression in the intuitive sense of the word2. Now Kripke’s considerations challenged this very two-level structure of meaning: he argued that especially proper names get their semantics via a direct, inmediated contact with the world – that their meaning does not mediate their contact with a thing, but directly is the thing. This may be not so surprising in case of proper names (after all, it is even disputable whether they can be counted to the language – for you cannot find them in dictionaries), but Kripke went on to argue that the same holds also for some other expressions, especially natural kind terms such as “cow” or “water”. Kripke’s argumentation is concise and flattening; and it has been provoking a lot of discussions..