Marie Duží

This paper examines different kinds of definite descriptions denoting purely contingent, necessary or impossible objects. The discourse about contingent/impossible/necessary objects can be organised in terms of rational questions to ask and answer relative to the modal profile of the entity in question. There are also limits on what it is rational to know about entities with this or that modal profile. We will also examine epistemic modalities; they are the kind of necessity and possibility that is determined by epistemic constraints related to knowledge or rationality. Definite descriptions denote so-called offices, roles, or things to be. We explicate these -offices as partial functions from possible worlds to chronologies of objects of type , where  is mostly the type of individuals. Our starting point is Prior’s distinction between a ‘weak’ and ‘strong’ definite article ‘the’. In both cases, the definite description refers to at most one object; yet, in the case of the weak ‘the’, the referred object can change over time, while in the case of the strong ‘the’, the object referred to by the definite description is the same forever, once the office has been occupied. The main result we present is the way how to obtain a Wh-knowledge about who or what plays a given role presented by a hyper-office, i.e. procedure producing an office. Another no less important result concerns the epistemic necessity of the impossibility of knowing who or what occupies the impossible office presented by a hyper-office.

Circumstantialists already have a logical semantics for impossibilities. They expand their logical space of possible worlds by adding impossible worlds. These are impossible circumstances serving as indices of evaluation, at which impossibilities are true. A variant of circumstantialism, namely modal Meinongianism (noneism), adds impossible objects as well. These are so-called incomplete objects that are necessarily non-existent. The opposite of circumstantialism, namely structuralism, has some catching-up to do. What might a structuralist logical semantics for impossibilities without impossibilia look like? This paper makes a structuralist counterproposal. We present a semantics based on a procedural interpretation of the typed λ-calculus. The fundamental idea is that talk about impossibilities should be construed in terms of procedures: some yield as their product a condition that could not possibly have a satisfier, while the rest fail to yield a product altogether. Dispensing with a ‘bottom’ of impossibilia requires instead a ‘top’ consisting of structured hyperintensions, intensions, intensions defining other intensions, a typed universe, and dual (de dicto and de re) predication. We explain how the theory works by going through several examples.

We prove how to validly quantify into hyperpropositional contexts de dicto in Transparent Intensional Logic. Hyperpropositions are sentential meanings and attitude complements individuated more finely than up to logical equivalence. A hyperpropositional context de dicto is a context in which only co-hyperintensional propositions can be validly substituted. A de dicto attitude ascription is one that preserves the attributee’s perspective when one complement is substituted for another. Being an extensional logic of hyperintensions, Transparent Intensional Logic validates all the rules of extensional logic, including existential quantification. Yet the rules become more exacting when applied to hyperintensional contexts. The rules apply to only some types of entities, because the existence of only some types of entities is entailed by a hyperpropositional attitude de dicto. The insight that the paper offers is how a particular logic of hyperintensions is capable of validating quantifying-in in a principled and rigorous manner. This result advances the community-wide understanding of how to logically manipulate hyperintensions.

The Kantian idea that some judgments are synthetic even in the area of a priori judgments cannot be accepted in its original version, but a modification of the notions analytic' and 'synthetic' discovers a rational core of that idea. The new definition of 'analytic' concerns concepts and makes it possible to distinguish between analytic concepts, which are effective ways of computing recursive functions, and synthetic concepts, which either define non-recursive functions, or define recursive functions in an ineffective way. To justify this claim we have to construe concepts as abstract procedures not reducible to set-theoretical entities.

In a multiagent and multi-cultural world, the fine-grained analysis of agents’ dynamic behaviour, i.e. of their activities, is essential. Dynamic activities are actions that are characterized by an agent who executes the action and by other participants of the action. Wh-questions on the participants of the actions pose a difficult particular challenge because the variability of the types of possible answers to such questions is huge. To deal with the problem, we propose the analysis and classification of Wh-questions apt for agents’ communication in a multiagent system (MAS). Our proposal of such a system consists of agents who communicate with their fellow agents by messaging so that each autonomous agent, though resource-bounded, can make less or more rational decisions to meet its own and collective goals. In addition, by communicating with other fellow agents and their environment, agents can learn new concepts and enrich their ontology so that their behaviour is dynamic. We aim to make a general proposal of the system so that the ‘envelope’ of agents’ messages can be formalized in any MAS standard, be it The Foundation for Intelligent Physical Agents - Agent Communication Language (FIPA-ACL) or Knowledge Query and Manipulation Language (KQML). Yet, the content of messages is encoded in a formalized natural language. To this end, we apply Transparent Intensional Logic (TIL) with its procedural semantics which is particularly apt for a fine-grained analysis in which all the semantically salient features of natural language can be plausibly formalized. In this paper, we concentrate on analysing the content of query messages, particularly the content of those that encode Wh-questions and the answers to them. We also summarize TIL deduction system that makes it possible to answer such questions in an intelligent way. Linguists distinguish several subtypes of Wh-questions. Though the linguistic classification is helpful, it is not always suitable for agents’ communication and reasoning. We need the classification based on a logical analysis of Wh-questions so that the agents can infer possible answers to such questions rather than only looking for them by keywords. This paper aims to apply an appropriate classification of the logical types of Wh-questions and the analysis of such questions; we concentrate in particular on questions concerning the participants of activities. The application of these results to the analysis of processes and events based on verb valency frames is another novelty of the paper.

The book is about logical analysis of natural language. Since we humans communicate by means of natural language, we need a tool that helps us to understand in a precise manner how the logical and formal mechanisms of natural language work. Moreover, in the age of computers, we need to communicate both with and through computers as well. Transparent Intensional Logic is a tool that is helpful in making our communication and reasoning smooth and precise. It deals with all kinds of linguistic context in a fully compositional and anti-contextual way.

There are many kinds of negation and denial. Perhaps the most common is the Boolean negation not that applies to propositions-in-extension, i.e. truth-values. The others are, inter alia, the property of propositions of not being true which applies to propositions; the complement function which applies to sets; privation which applies to properties; negation as failure applied in logic programming; negation as argumentation ad absurdum, and many others. The goal of this paper is neither to provide a complete list, nor to analyse all of them. Rather, I am going to deal with negation of propositions that come attached with a presupposition that is entailed by the positive as well as negated form of a given proposition. However, there are two kinds of negation, namely internal and external negation. I am going to prove that while the former is presupposition-preserving, the latter is presupposition-denying. This issue has much in common with the difference between topic and focus articulation within a sentence. Whereas articulating the topic of a sentence activates a presupposition, articulating the focus frequently yields merely an entailment. The main contribution of this paper is the proof that the two kinds of negation are not equivalent. While the Russellian wide-scope (external) negation gets the truthconditions of a sentence right for a subject occurring as a focus, Strawsonian narrow-scope (internal) negation is validly applicable for a subject occurring as the topic. I also deal with other kinds of presupposition triggers, in particular factive attitudes and prerequisites of a given property. My background theory is Transparent Intensional Logic (TIL). TIL is an expressive logic apt for the analysis of sentences with presuppositions, because in TIL we work with partial functions, in particular with propositions with truth-value gaps. Moreover, the procedural semantics of TIL make it possible to uncover the hidden semantic features of sentences, make them explicit and logically tractable.

In the paper I analyse Anselm’s ontological arguments in favour of God’s existence. The analysis is an explication and formalization of Pavel Tichý’s study‘Existence and God’, Journal of Philosophy, 1979. It is based on Transparent Intensional Logic with its bi-dimensional ontology of entities organized in the ramified hierarchy of types. The analysis goes as follows. First, necessary notions and principles are introduced. They are: (a) existence is not a (non-trivial) property of individuals, but of individual offices to be occupied by an individual; (b) the notion of requisite is defined, which is a necessary relation between an office O and a property R: necessarily, if a happens to occupy O then a has the property R. (c) I demonstrate that an argument of the form “R is a requisite of O, hence the holder of O has the property R” is invalid. In order to be valid, it must be of the form “R is a requisite of O, the office O is occupied, hence the holder of O has the property R.” Finally, (d) higher-order offices that can be occupied by individual offices are defined. Their requisites are properties of individual offices. Then the analysis of Anselm’s arguments is presented. The expression ‘God’ denotes an individual office, a ‘thing to be’, rather than a particular individual. Thus the question whether God exists is a legitimate one. I analyze the expression ‘that, than which nothing greater can be conceived’. Since ‘greater than’ is a relation-in-intension between individual offices here, the expression denotes a second-order office, and its requisites are properties of first-order offices suchas necessary existence. The second of Anselm’s assumptions is that individual office that has the property of necessary existence is greater than any other office lacking this property. From these it follows that the first-order holder of the office denoted by ‘that, than which nothing greater can be conceived’ (that is God) enjoys the property of necessary existence. Thus God exists necessarily, hence also actually. Anselm’s argument is logically valid. If it were also sound, then an atheist would differ from a believer only by the former not believing whereas the latter believing in a tautology, which is absurd. Yet we may doubt the validity of Anselm’s assumption that a necessary existence makes an office greater than any other office lacking this property.

This paper deals with two issues. First, it identifies structured propositions with logical procedures. Second, it considers various rigorous definitions of the granularity of procedures, hence also of structured propositions, and comes out in favour of one of them. As for the first point, structured propositions are explicated as algorithmically structured procedures. I show that these procedures are structured wholes that are assigned to expressions as their meanings, and their constituents are sub-procedures occurring in executed mode. Moreover, procedures are not mere aggregates of their parts; rather, procedural constituents mutually interact. As for the second point, there is no universal criterion of the structural isomorphism of meanings, hence of co-hyperintensionality, hence of synonymy for every kind of language. The positive result I present is an ordered set of rigorously defined criteria of fine-grained individuation in terms of the structure of procedures. Hence procedural semantics provides a solution to the problem of the granularity of co-hyperintensionality.

The topic of this special issue of Synthese is hyperintensionality. This introduction offers a brief survey of the very notion of hyperintensionality followed by a summary of each of the papers in this collection. The papers are foundational studies of hyperintensionality accompanied by ample philosophical applications.Hyperintensionality concerns the individuation of non-extensional entities such as propositions and properties, relations-in-intension and individual roles, as well as, for instance, proofs and judgments and computational procedures, in case these do not reduce to any of the former. Hyperintensional individuation is frequently also referred to as ‘fine-grained’ or sometimes simply ‘intensional’ individuation, when ‘intensional’ is not understood in the specific sense of possible-world semantics or in the pejorative sense of flouting various logical rules of extensional logic. A principle of individuation qualifies as hyperintensional as soon as it is finer than necessary ..

The standard rule of single privative modification replaces privative modifiers by Boolean negation. This rule is valid, for sure, but also simplistic. If an individual a instantiates the privatively modified property (MF) then it is true that a instantiates the property of not being an F, but the rule fails to express the fact that the properties (MF) and F have something in common. We replace Boolean negation by property negation, enabling us to operate on contrary rather than contradictory properties. To this end, we apply our theory of intensional essentialism, which operates on properties (intensions) rather than their extensions. We argue that each property F is necessarily associated with an essence, which is the set of the so-called requisites of F that jointly define F. Privation deprives F of some but not all of its requisites, replacing them by their contradictories. We show that properties formed from iterated privatives, such as being an imaginary fake banknote, give rise to a trifurcation of cases between returning to the original root property or to a property contrary to it or being semantically undecidable for want of further information. In order to determine which of the three forks the bearers of particular instances of multiply modified properties land upon we must examine the requisites, both of unmodified and modified properties. Requisites underpin our presuppositional theory of positive predication. Whereas privation is about being deprived of certain properties, the assignment of requisites to properties makes positive predication possible, which is the predication of properties the bearers must have because they have a certain property formed by means of privation.

We demonstrate how to validly quantify into hyperintensional contexts involving non-propositional attitudes like seeking, solving, calculating, worshipping, and wanting to become. We describe and apply a typed extensional logic of hyperintensions that preserves compositionality of meaning, referential transparency and substitutivity of identicals also in hyperintensional attitude contexts. We specify and prove rules for quantifying into hyperintensional contexts. These rules presuppose a rigorous method for substituting variables into hyperintensional contexts, and the method will be described. We prove the following. First, it is always valid to quantify into hyperintensional attitude contexts and over hyperintensional entities. Second, factive empirical attitudes validate, furthermore, quantifying over intensions and extensions, and so do non-factive attitudes, both empirical and non-empirical , provided the entity to be quantified over exists. We focus mainly on mathematical attitudes, because they are uncontroversially hyperintensional

In 1905 Bertrand Russell took on the problem of definite descriptions, and his analysis became the standard up until 1950 when Peter Strawson criticised Russell’s solution as inadequate. Since then many opponents as well as proponents of the Russellian solution have been involved in a long-term debate on definite descriptions. In this paper I show that both sides of the contention are partly right and partly wrong, because sentences of the form “The F is a G” are ambiguous. However, the ambiguity does not concern reference shift of the description ‘the F’. Rather, the ambiguity consists in different topic-focus articulations of a given sentence involving occurrences of ‘the F’. I demonstrate that when ‘the F’ is used as part of the topic of such a sentence the existence of the object denoted by ‘the F’ is not only entailed by but also presupposed by the sentence. On the other hand, ‘the F’ used in the focus of a sentence triggers merely existential entailment. Thus sentences differing only in their topic-focus articulation should have assigned different logical forms. In order to make such hidden features explicit, I apply the procedural semantics of Transparent Intensional Logic , furnishing sentences with hyperpropositions that are precisely defined in terms of TIL constructions. These are procedures assigned to sentences as their context-invariant structured meanings. Moreover, I generalise the phenomenon of the topic-focus distinction to sentences of any form, proposing an adequate analytic schema of sentences that come with a presupposition

In the paper we offer a logical explication of the frequently used, but rather vague, notion of point of view. We show that the concept of point of view prevents certain paradoxes from arising. A point of view is a means of partial characterisation of something. Thus nothing is a P and at the same time a non-P , because it is a P only relative to some point of view and a non-P from another point of view. But there is a major, complicating factor involved in applying a logical method that is supposed to provide a formal and rigorous counterpart of the intuitively understood notion: ‘point of view’ is a homony-mous expression, and so there is not just one meaning that would explain points of view. Yet we propose a common scheme of the logical type of the entities denoted by the term ‘point of view’. It is an empirical function: when applied to the viewed object in question, it results in a evaluating proposition about the object. If there is an agent applying the criterion, the result is the agent’s attitude to the respective object. The paper is organised into two parts. In Part I we first adduce and analyse various examples of typical cases of applying a point of view to prevent paradox. These cases are examined according to the type of the viewed object: a) the viewed object is an individual and b) the viewed object is a property or an office. In Part II we then show that the method described in Part I can be applied also to the analyses of agents’ attitudes. We thus explain how an agent can believe of something that it is a P and at the same time a non-P: the agent applies different viewpoint criteria to the viewed object. The inversion of perspective consisting in the perspective shifting from the believer on to the reporter in the case of attitudes de re, and from the reporter to the believer in the case of attitudes de dicto, is also analyzed. We show that there is no smooth logical traffic back and forth between such attitudes and prove that they are not equivalent. By way of conclusion, we explicate the notion of conceptual point of view and analyze cases of viewpoints given by conceptual distinction. We show, finally, that the proposed scheme of the type of point of view can be preserved, this time, however, in its extensional version

The classical theory of semantic information (ESI), as formulated by Bar-Hillel and Carnap in 1952, does not give a satisfactory account of the problem of what information, if any, analytically and/or logically true sentences have to offer. According to ESI, analytically true sentences lack informational content, and any two analytically equivalent sentences convey the same piece of information. This problem is connected with Cohen and Nagel's paradox of inference: Since the conclusion of a valid argument is contained in the premises, it fails to provide any novel information. Again, ESI does not give a satisfactory account of the paradox. In this paper I propose a solution based on the distinction between empirical information and analytic information. Declarative sentences are informative due to their meanings. I construe meanings as structured hyperintensions, modelled in Transparent Intensional Logic as so-called constructions. These are abstract, algorithmically structured procedures whose constituents are sub-procedures. My main thesis is that constructions are the vehicles of information. Hence, although analytically true sentences provide no empirical information about the state of the world, they convey analytic information, in the shape of constructions prescribing how to arrive at the truths in question. Moreover, even though analytically equivalent sentences have equal empirical content, their analytic content may be different. Finally, though the empirical content of the conclusion of a valid argument is contained in the premises, its analytic content may be different from the analytic content of the premises and thus convey a new piece of information

V příspěvku podávám přehled vývoje logické sémantiky se zřetelem zejména na vý­voj Tichého Transparentní intenzionální logiky (TIL) od pozdních šedesátých let až do­dnes, a na ní vystavěné Maternovy logické teorie pojmu. Článek si neklade za cíl podat vyčerpávající historický přehled, nýbrž soustřeďuje se na podíl česko-slovenské logické školy a ukazuje, že tento podíl je nezanedbatelný. Navíc je však tento přehled zároveň i kritický. Ukazuje silné stránky logického rámce TIL, ale zároveň upozorňuje na někte­ré diskutabilní stránky či otevřené problémy, které zůstávají zejména právě v procedu­rální teorii pojmu. Z nich nejpalčivějším je problém procedurální identity pojmu, a tím také kritéria synonymie.

In the paper we offer a logical explication of the frequently used, but rather vague, notion of point of view. We show that the concept of point of view prevents certain paradoxes from arising. A point of view is a means of partial characterisation of something. Thus nothing is a P and at the same time a non-P, because it is a P only relative to some point of view and a non-P from another point of view. But there is a major, complicating factor involved in applying a logical method that is supposed to provide a formal and rigorous counterpart of the intuitively understood notion: ‘point of view’ is a homonymous expression, and so there is not just one meaning that would explain points of view. Yet we propose a common scheme of the logical type of the entities denoted by the term ‘point of view’. It is an empirical function: when applied to the viewed object in question, it results in a evaluating proposition about the object. If there is an agent applying the criterion, the result is the agent’s attitude to the respective object. The paper is organised into two parts. In Part I we first adduce and analyse various examples of typical cases of applying a point of view to prevent paradox. These cases are examined according to the type of the viewed object: a) the viewed object is an individual and b) the viewed object is a property or an office. In Part II we then show that the method described in Part I can be applied also to the analyses of agents’ attitudes. We explain how an agent can believe of something that it is a P and at the same time a non-P: the agent applies different viewpoint criteria to the viewed object. The inversion of perspective consisting in the perspective shifting from the believer on to the reporter in the case of attitudes de re, and from the reporter to the believer in the case of attitudes de dicto, is also analyzed. We show that there is no smooth logical traffic back and forth between such attitudes unless some additional assumptions are added, and prove that they are not equivalent. By way of conclusion, we explicate the notion of conceptual point of view and analyze cases of viewpoints given by conceptual distinction. We show, finally, that the proposed scheme of the type of point of view can be preserved, this time, however, in its extensional version.

Our knowledge, beliefs, doubts, etc., concern primarily logical constructions of propositions. If we assume that iterating ‘belief attitudes’ is valid, i.e., that the agent is perfectly introspective, he knows what he knows, believes, etc., then the so-called propositional attitudes are actually hyperintensional attitudes, i.e., they are relations of an agent to the construction–concept expressed by the embedded clause. Their implicit counterparts, relations of an agent to the proposition denoted by the embedded clause, are just idealised cases of an agent with unlimited inferential abilities. On the other hand, our wishes, intentions, seeking, finding, etc., concern particular intensions , and the so-called notional attitudes are not hyperintensional. In the paper we formulate some criteria for notional attitudes and examine basic categories of them. In general, notional attitudes are relations-in-intension between an agent and an object to which the agent is intentionally related. Even relations of an agent to a proposition can be notional ones, in case there is no salient constructional counterpart, the attitude is not influenced by agent’s inferential abilities. Another problem we meet is the ambiguity of sentences expressing notional attitudes. These statements can often be read both in the de dicto and in the de re way. Yet, a common feature that characterizes notional attitudes is using the construction of the respective intension in the de dicto way. The respective intension is mentioned; referring on such a situation, the reporter may use any of the equivalent constructions of the intension, but not just a co-referring notion of another intension. Still, unlike the cases of relations of an agent to an individual when the respective individual office serves just as a pointer to the individual, when referring on notional attitudes the use of the respective notion of the intension is indispensable, which might perhaps justify calling such attitudes notional, though they actually are intensional. We also show that a passive form of a sentence cannot be usually read in the de dicto way . Thus a common belief at the equivalence of the active and passive form of a statement is generally not justified