Jaroslav Peregrin

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..

In a remarkable early paper, Wilfrid Sellars warned us that if we cease to recognize rules, we may well find ourselves walking on four feet; and it is obvious that within human communities, the phenomenon of rules is ubiquitous. Yet from the viewpoint of the sciences, rules cannot be easily accounted for. Sellars himself, during his later years, managed to put a lot of flesh on the normative bones from which he assembled the remarkable skeleton of the early paper; and his followers too. However, what they say is somewhat divergent; and therefore my aim in this paper is to concentrate on the very concept of rule and analyse it in the context of the question what it is about us humans that makes us special

In this paper I put forward a thesis regarding the anatomy of “cultural evolution”, in particular the way the “cultural” transmission of behavioral patterns came to piggyback, through us humans, on the transmission effected by genetic evolution. I claim that what grounds and supports this new kind of transmission is a complex behavioral “meta-pattern” that makes it possible to grasp a pattern as something that “ought to be”, i.e. that transforms the pattern into what we can call a rule. (Here I draw especially on the philosophical insights of Wilfrid Sellars.) In this way I interlink empirical research done in evolution theory with some more speculative philosophical theories, thus shedding new light on the former and adding an empirical footing to the latter

Filosofové odedávna snili o jazyce, který by byl z hlediska řešení těch problémů, se kterými se potýkají (případně všech lidských problémů vůbec), vhodnější než jazyk, jímž nás obdařila příroda. Mnozí z nich si představovali, že filosofické problémy vznikají zčásti nebo zcela v důsledku toho, že přirozený jazyk není dostatečně přesným prostředkem vyjádření našich idejí a myšlenek - a že by se tedy vše spravilo, kdyby byl k dispozici jazyk, jehož výrazivo by bylo s našim myšlením - případně s naším světem - v dokonalém souladu. Podle tohoto názoru je tím, co filosof (ale i vědec) potřebuje, jakási „abeceda lidských myšlenek“, která by nám umožnila „pomocí spojení jejích písmen a analýzy slov, která se z nich skládají, objevit a posoudit všechno ostatní“ (Leibniz) K tomu, aby se taková „abeceda“ dala vytvořit, ovšem zbývala jedna ‘maličkost’: bylo třeba posbírat a zinventarizovat všechny naše myšlenky a ideje, zjistit, pro které vyjádření nemáme, případně které vyjadřujeme nějak ‘nevhodně’, a tyto nedostatky a nesrovnalosti odstranit. Problém byl ovšem v tom, že nikdo neměl nejmenší ponětí, jak tohle udělat: a Leibnizův projekt calculu philosophicu, stejně tak jako jiné podobné nápady, zůstal navždy pouhou utopií.

Th is review article discusses Rebecca Kukla and Mark Lance’s (2009) book on normative speech act theory and Joseph Heath’s (2008) book on rule following, putting them into the context of the general problem of normativity of human discursive practices (and human practices in general). Th e upshot of the discussion is that while Heath’s book advances our understanding of the normative dimension of human life, prominently including human language, Kukla and Lance’s one presents a deeply interesting attempt at a framework for the study of discourse taking normativity of language at face value

What do we learn when we find out that an argument is logically incorrect? If logically incorrect means the same as not logically correct, which in turn means not having a valid logical form, it seems that we do not learn anything too useful—an argument which is logically incorrect can still be conclusive. Thus, it seems that it makes sense to fix a stronger interpretation of the term under which a logically incorrect argument is guaranteed to be wrong. In this paper, we show that pinpointing this stronger sense is much trickier than one would expect; but eventually we reach an explication of the notion of logical incorrectness which we find non-trivial and viable.

The paper presents an argument against a "metaphysical'* conception of logic according to which logic spells out a specific kind of mathematical structure that is somehow inherently related to our factual reasoning. In contrast, it is argued that it is always an empirical question as to whether a given mathematical structure really does captures a principle of reasoning. lMore generally, it is argued that it is not meaningful to replace an empirical investigation of a thing by an investigation of its a priori analyzable structure without paying due attention to the question of whether it really is the structure of the thing in question.) It is proposed to elucidate the situation by distinguishing two essentially different realms with which our reason must deal: "the realm of the natural'*, constituted by the things of our empirical world, and "the realm of the formal'*, constituted by the structures that we use as "prisms'* to view, to make sense of, and to reconstruct the world. It is suggested that this vantage point may throw light on many foundational problems of logic

Abstrakt. Běžně se má za to, že pravidla hrají v rámci myšlení jenom marginální úlohu. Myšlení je přece proces, který je svou podstatou svobodný, ne-mechanický a kreativní – a tudíž nikoli řízený nějakými pravidly. Často se má dokonce za to, že je to právě absence pravidel, která dělá z lidského myšlení to, čím je, a co člověka principiálně odlišuje od stroje. V ostrém kontrastu k tomuto pohledu stojí Wittgensteinův výrok, že vlastně nemůžeme překročit hranice logiky – že nemůžeme myslet tak, aby to bylo s pravidly logiky v rozporu. Jak mohl Wittgenstein tvrdit něco, co zní tak očividně nesmyslně? V přednášce se chci podívat na roli, kterou v rámci myšlení hrají pravidla, z poněkud jiného pohledu, než jak to bývá běžné. Nemyslím, že by existovala nějaká pravidla, která by obecně vedla naše myšlenkové pochody; jsem však přesvědčen, že jistý druh pravidel hraje z hlediska myšlení skutečně klíčovou roli – jsou to ta, která konstituují 'prostor významů', o něž se naše myšlení standardně opírá.

Pavel Materna je logikem a filosofem, na kterého se, domnívám se, mimořádně hodí anglický přívlastek single-minded, který bohužel nemá v češtině skutečný ekvivalent. Materna již dávno přijal za svůj ten pojmový rámec, který stojí v základě systému transparentní intenzionální logiky (TIL) vyvinuté Pavlem Tichým, a tento rámec se mu stal měřítkem všech věcí, jsoucích že jsou a nejsoucích že nejsou. Ani jeho poslední kniha Concepts and Objects, která vyšla v ediční řadě vydávané Filosofickou společností Finska, není v tomto směru výjimkou: ani ona není ničím jiným než jistou formou rozpracování a aplikace TIL. Tato kniha se ale přece jenom, zdá se mi, od předchozích Maternových publikací poněkud liší, a to způsobem, který je třeba přivítat. Zatímco v minulosti se Maternova soustředěnost na TIL často projevovala i jeho neochotou zabývat se názory s TIL nekompatibilními a hovořit i k lidem, který tento systém za svůj neberou, v knize Concept and Object se Materna více než kdy předtím pokusil vymezit TIL oproti jiným logickým a filosofickým systémům a u mnohých problémů, kterými se v knize zabývá, se pokusil jasněji než kdy předtím vyjádřit, proč je podle něj ten přístup, který on volí, lepší než přístupy jiné. První..

Existuje překvapivě málo knih, které by se pokoušely o syntetizující pohled na analytickou filosofii. Je ovšem pravda, že ve druhé polovině našeho století se soubor filosofů, kteří se k analytické filosofii hlásí nebo kteří k ní bývají řazeni, stává natolik různorodý, že se jakákoli syntéza stává problematickou; překvapivě málo syntetizujících prací existuje ale i o ‘klasické’ analytické filosofii, to jest o analytické filosofii období zhruba od konce devatenáctého století do poloviny století dvacátého. Dejnožkova kniha je jednou z těch mála, které se o něco takového pokouší, a to je třeba přivítat. Dejnožka se ovšem nesnaží podat všestranný rozbor názorů klasiků analytické filosofie; soustředí se pouze jeden aspekt jejich učení, totiž na jejich ontologii. Hned v úvodu své knihy k tomu vysvětluje, jaké opodstatnění může mít hovořit o ontologii u takového druhu filosofie, která se programově distancuje od metafyziky. Podle něj je tomu tak, že i když se někteří analytičtí filosofové někdy více či méně úspěšně vyhýbali otázkám metafyzickým (to jest otázkám po nejzákladnějších kategoriích bytí), ontologickým otázkám (to jest otázkám po povaze bytí jako takového) se v podstatě vyhnout nelze. A Dejnožka se snaží ukázat, že klasikové analytické filosofie se těmito otázkami zabývali mnohdy velice do hloubky. To je patrné zejména u Frega a Russella, kterým autor věnuje největší pozornost; avšak k těm, kteří podle Dejnožky berou ústřední otázku ontologie za svou, řadí Dejnožka i Wittgensteina i Quina (jimž se však věnuje na pouze velice omezeném prostoru - každému asi na dvanácti stránkách).

A few decades ago, only isolated groups of philosophers counted the phenomenon of normativity as one of their principal interests. Rules and norms have always, of course, been in the purview of moral philosophers, who often took them as exceedingly abstract entities, if not directly metaphysical. Philosophers from the border territories of philosophy and social sciences, on the other hand, were interested in more concrete norms, namely those that emerge and survive within human societies. Philosophers of law stood between these two extremes, studying law as a matter of socially instituted norms which, however, might be seen as a projection of something more esoteric. The research programs of these groups of philosophers had little overlap. And for philosophers of mind, of language, or of science (with the exception of a few philosophers of social sciences, such as Peter Winch), norms were at most only of marginal interest. This situation has changed hugely over recent decades. I think the catalyst was the interest in rules and norms within the philosophy of language, which was kindled by the ongoing reception of the later Wittgenstein. Other philosophers, like Michael Dummett and Wilfrid Sellars, also deserve part of the credit. Via philosophy of language, interest in norms invaded sections of philosophy of mind, too, and the previously isolated studies of various types of norms slowly became interconnected, if not directly integrated. No wonder that more and more general studies of the nature of rules and norms are now reaching the light of day. Andrei Marmor's Social Conventions is one of the most recent contributions. Marmor sees a social convention as a specific kind of norm characterized especially by its arbitrariness. More precisely, a rule is conventional, according to the author, iff (i) some people follow it; (ii) they have a reason to follow it; and (iii) there is an alternative rule that they could have followed for the same reason. The point of departure for Marmor's analysis is David Lewis's theory of convention F1F, which, however, he considers too narrow and hence extends it considerably. Lewis's idea is that norms result from certain spontaneous processes by which society reacts to coordination problems..

What is a minimal proof-theoretical foundation of logic? Two different ways to answer this question may appear to offer themselves: reduce the whole of logic either to the relation of inference, or else to the property of incompatibility. The first way would involve defining logical operators in terms of the algebraic properties of the relation of inference—with conjunction $$\hbox {A}\wedge \hbox {B}$$ A ∧ B as the infimum of A and B, negation $$\lnot \hbox {A}$$ ¬ A as the minimal incompatible of A, etc. The second way involves introducing logical operators in terms of the relation of incompatibility, such that X is incompatible with $$\{\lnot \hbox {A}\}$$ { ¬ A } iff every Y incompatible with X is incompatible with {A}; and X is incompatible with $$\{\hbox {A}\!\wedge \!\hbox {B}\}$$ { A ∧ B } iff X is incompatible with {A,B}; etc. Whereas the first route leads us naturally to intuitionistic logic, the second leads us to classical logic. The aim of this paper is threefold: to investigate the relationship of the two approaches within a very general framework, to discuss the viability of erecting logic on such austere foundations, and to find out whether choosing one of the ways we are inevitably led to a specific logical system

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.

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 Willard Van Orman Quine and Willfrid Sellars, and coming to full 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: (1) the atomistic character of language; (2) the sharp boundary between analytic and contingent statements; (3) the sharp boundary between 'given' and 'inferred' knowledge; and also (4) 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

The “dynamic turn” in semantic theory of natural language, which has been taking place roughly during the last decade, has resulted into seeing the meaning of a sentence as a “context-change-potential”, as a function which maps the set of possible contexts on itself. The development of theories of this kind has been stimulated especially by the effort to semantically cope with the anaphoric items of natural language . The most significant species of dynamic semantic theories are represented by Kamp´s “discourse representations theory” and Groenendijk and Stokhof´s “dynamic logic”. The former sees sentences as means of building and rebuilding “discourse representations structures”; the latter, which tries to be an expressly logical objects to “discourse markers” into the same set. The paper presents basic principles of theories of both of these kinds and indicates how they can help us analyse natural language locutions involving anaphora