Robert van Rooij - Academia.edu (original) (raw)

Papers by Robert van Rooij

We give derivations of two formal models of Gricean Quantity implicature and strong exhaustivity ... more We give derivations of two formal models of Gricean Quantity implicature and strong exhaustivity in bidirectional optimality theory and in a signalling games framework. We show that, under a unifying model based on signalling games, these interpretative strategies are game-theoretic equilibria when the speaker is known to be respectively minimally and maximally expert in the matter at hand. That is, in this framework the optimal strategy for communication depends on the degree of knowledge the speaker is known to have concerning the question she is answering. In addition, and most importantly, we give a game-theoretic characterisation of the interpretation rule Grice (formalising Quantity implicature), showing that under natural conditions this interpretation rule occurs in the unique equilibrium play of the signalling game.

One of the traditional pragmatic approaches to vagueness suggests that there needs to be a signif... more One of the traditional pragmatic approaches to vagueness suggests that there needs to be a significant gap between individuals or objects that can be described using a vague adjective like tall and those that cannot. In contrast, intuitively, an explicit comparative like taller does not require fulfillment of the gap requirement. Our starting point for this paper is the consideration that people cannot make precise measures under time pressure and their ability to discriminate approximate heights (or other values) obeys Weber's law. We formulate and experimentally test three hypotheses relating to the difference between positive and comparative forms of the vague adjectives, gap requirement, and Weber's law. In two experiments, participants judged appropriateness of usage of positive and comparative forms of vague adjectives in a sentence-picture verification task. Consequently, we review formal analysis of vagueness using weak orders and semi-orders and suggest adjustments based on the experimental results and properties of Weber's law. * Thanks to the Dutch NWO gravitation project Language in Interaction, the ESSENCE Marie Curie Initial Training Network, and the project 'Logicas no-transitivas. Una nueva aproximacion a las paradojas' for financially supporting this project. The authors also thank Nicole Standen-Mills for professional proofreading. John Mary According to Kennedy's (2011) intuition, this picture allows us to say (1-a). At the same time, his intuition is that (1-b) is false. (1) a. John is taller than Mary. b. Compared to Mary, John is tall, but compared to John, Mary is not tall. Kennedy proposes that whereas for the truth of the explicit comparative (1-a) any (directly or indirectly observable) bit of John's height that exceeds Mary's suffices, there should be a significant gap between the heights of John and Mary for the implicit comparative (1-b) to be true. According to Kennedy (2011), such a significant gap is also required to make the positive sentence (2) true with respect to an implicit comparison class: (2) John is tall. As it turns out, Kennedy's intuition concerning (2) fits well with a pragmatic approach towards clustering proposed by various philosophers to (dis)solve the Sorites paradox. The pragmatic gap requirement We can divide people into those that are tall and those that are not. How do we do so? What is the criterion? According to the most obvious solution, everybody is tall whose height is above a certain cutoff-point, where every bit of height suffices. But that gives rise to several questions: (i) How do we determine the cutoff-point? Is it the mean height of the relevant persons, the median height, or something else? 1 (ii) How does this proposal account for the intuition that some people are borderline cases of tall people? (iii) Doesn't this presuppose that we need to be able to measure people's height before we can classify people as tall, and isn't that problematic? Suppose we have settled question (i). How, then to account for borderline cases? A natural proposal would have it that those individuals are borderline tall for which we cannot determine whether they are above or below the cutoff-point. This could be because our measurement is in many cases imprecise. But once we allow for this, we immediately get into

Springer eBooks, 2014

Properties as set of individuals, or of features? Worlds, or propositions? Time-points, or events... more Properties as set of individuals, or of features? Worlds, or propositions? Time-points, or events? Preference, or choice? Natural kinds, or similarity? In modern analytic philosophy it is standard to take (i) individuals as basic, and properties as defined in terms of them; (ii) worlds as basic, and propositions as defined in terms of them; (iii) time-points as basic, and intervals as constructions out of them; (iv) preference as basic, and optimal choice as defined in terms of them; and (v) natural kinds as basic, and similarities as defined in terms of them. In this paper we show that in all cases the other direction is possible as well. Most of the constructions used are well-known. But by putting them collectively on the table we hope to show that the constructions have something in common, and that it is not always clear which perspective is ontologically less committing.

Linguistics and Philosophy, Jul 23, 2019

Cimpian et al. (2010) observed that we accept generic statements of the form 'Gs are f ' on relat... more Cimpian et al. (2010) observed that we accept generic statements of the form 'Gs are f ' on relatively weak evidence, but that if we are unfamiliar with group G and we learn a generic statement about it, we still treat it inferentially in a much stronger way: (almost) all Gs are f. This paper makes use of notions like 'representativeness', 'contingency' and 'relative difference' from (associative learning) psychology to provide a uniform semantics of generics that explains why people accept generics based on weak evidence. The spirit of the approach has much in common with Leslie's cognitionbased ideas about generics, but the semantics will be grounded on a strengthening of Cohen's (1999) relative readings of generic sentences. In contrast to Leslie and Cohen, we propose a uniform semantic analysis of generics. The basic intuition is that a generic of the form 'Gs are f ' is true because f is typical for G, which means that f is valuably associated with G. We will make use of Kahneman and Tversky's Heuristics and Biases approach, according to which people tend to confuse questions about probability with questions about representativeness, to explain pragmatically why people treat many generic statements inferentially in a much stronger way.

Communications in computer and information science, 2016

It is well-known that in combination with further premises that look less controversial, the tole... more It is well-known that in combination with further premises that look less controversial, the tolerance principle-the constraint that if P a holds, and a and b are similar in P-relevant respects, P b holds as well-leads to contradiction, namely to the sorites paradox. According to many influential views of the sorites paradox (e.g. Williamson 1994), we therefore ought to reject the principle of tolerance as unsound. There are reasons to think of such a view as too drastic and as missing out on the role that such a principle plays in categorization and in ordinary judgmental and inferential practice. Taking a different perspective, the tolerance principle ought not to be discarded that fast, even when viewed normatively. Instead, it corresponds to what might be called a soft constraint, or a default, namely a rule that we can use legitimately in reasoning, but that must be used with care. One family of approaches represents the tolerance principle by a certain conditional sentence, of the form: P a ∧ a ∼ P b → P b, and bestows special properties to the conditional to turn it into a soft constraint. One natural option is to use fuzzy logic, where v M (A) can be anywhere in [0, 1] and v M (A → B) = Min{1, 1 − v M (A) + v M (B)}. One can demand that the tolerance conditional may never have a value below 1 − ε for some small ε. Given an appropriate sorites sequence, it will be possible to have: v M (P a 1 → P a 2) = 1−ε, v M (P a 2 → P a 3) = 1 − ε, without having v M (P a 1 → P a 3) = 1 − ε. A different option is to treat the tolerance conditional as expressing a defeasible rule (like when '→' expresses a counterfactual conditional). Say that P a ∧ a ∼ P b → P b is true provided P b is true in all 'optimal' (P a ∧ a ∼ P b)worlds. Call a world (P a ∧ a ∼ P b)-optimal if a is P-similar to b but is not close to a borderline case of P. From P a ∧ a ∼ P b, P a ∧ a ∼ P b → P b, it need not follow that P b, since a world may satisfy P a ∧ a ∼ P b without being Except for the last section, this paper is an abridged version of a longer paper entitled "The Tolerance Principle: Nontransitive Reasoning or Nonmonotonic Reasoning?". We are indebted to two anonymous reviewers for helpful comments.

Axiomathes, Apr 25, 2020

According to Adams (Inquiry 8:166-197, 1965), the acceptability of an indicative conditional goes... more According to Adams (Inquiry 8:166-197, 1965), the acceptability of an indicative conditional goes with the conditional probability of the consequent given the antecedent. However, some conditionals seem to be inappropriate, although their corresponding conditional probability is high. These are cases with a missing link between antecedent and consequent. Other conditionals are appropriate even though the conditional probability is low. Finally, we have the so-called biscuit conditionals. In this paper we will generalize analyses of Douven (Synthese 164:19-44, 2008) and others to account for the appropriateness of conditionals in terms of evidential support. Our generalization involves making use of Value, or intensity. We will show how this generalization helps to account for biscuit conditionals and conditional threats and promises. Finally, a link is established between this analysis of conditionals and an analysis of generic sentences.

Springer eBooks, 2014

Venn diagrams are standardly used to give a semantics for Syllogistic reasoning. This interpretat... more Venn diagrams are standardly used to give a semantics for Syllogistic reasoning. This interpretation is extensional. Leibniz, however, preferred an intensional interpretation, according to which a singular and universal sentence is true iff the (meaning of) the predicate is contained in the (meaning of) the subject. Although Leibniz’s preferred interpretation played a major role in his philosophy (in Leibniz [16] he justifies his metaphysical ‘Principle of Sufficient Reason’ in terms of it) he was not able to extend his succesfull intensional interpretation (making use of characteristic numbers) without negative terms to one where also negative terms are allowed. The goal of this paper is to show how syllogistic reasoning with complex terms can be given a natural set theoretic ‘intensional’ semantics, where the meaning of a term is not defined in terms of individuals. We will make use of the ideas behind van Fraassen’s [6, 7] hyperintensional semantics to account for this.

A traditional issue in the analysis of comparatives is whether or not degrees are essential. In t... more A traditional issue in the analysis of comparatives is whether or not degrees are essential. In the first part of this paper I discuss the traditional analyses that account for comparatives with (Seuren, von Stechow) and without (Klein) degrees, and remind the reader that these are very similar to each other. A more recent issue is how to account for quantifiers in the than-clause. The traditional analyses account well for Negative Polarity Items in comparative clauses, but have problems with conjunctive quantifiers. The strength of the proposals of Larson (1988) and Schwarzchild & Wilkinson (2002), on the other hand, goes exactly in the opposite direction. I will discuss two types of strategies so as to account for both types of quantifiers: (i) one based on the traditional analysis, but by making use of more coarse-grained models or of intervals, (ii) one where comparatives are taken to be ambiguous between the traditional reading and the Larson-reading, and where the actual reading is selected with the help of the strongest meaning hypothesis. 2 The traditional analyses of comparatives There exist two major types of approaches to the analysis of gradable adjectives: comparison class approaches and degree-based approaches. In this section I sketch the traditional approaches along these lines, and show how close they are to each other. Intuitively, John can be counted as tall when we compare him with other men, but not tall when we compare him with (other) basketball players. Thus, whether someone of 1.80 meters is tall or not is context dependent. Wheeler (1972) and Klein (1980) propose that every adjective should be interpreted with respect to a comparison class. A comparison class is just a set of objects/individuals and is contextually given. In particular if the adjective stands alone, we might assume that the contextually given comparison class helps to determine what counts as being tall. Klein (1980) assumed that with respect to a given comparison class, some elements of this set are considered to be definitely tall, some definitely not tall, and the others are borderline cases. The truth of the positive sentence (1) (1) John is tall. * I have presented parts of this paper at various occasions. At a DIP colloquium in Amsterdam, at the CSSP 2007 workshop, and later at talks given in Utrecht and in Tokyo. I would like to thank the audiences for their remarks. I also would like to thank Chris Kennedy and Roger Schwarzchild for discussion. Robert van Rooij depends on the contextually given comparison class: (1) is true in context (or comparison class) c iff John is counted as tall in this class. The proposition expressed by a comparative like (2) is context independent. (2) John is taller than Mary. and the sentence is true iff there is a comparison class according to which John counts as tall, while Mary does not: ∃c[T (j , c) ∧ ¬T (m, c)]. 1 According to the degree-based approaches (e.g.

Lecture Notes in Computer Science, 2011

Vagueness is a pervasive feature of natural language, but indeed one that is troubling for leadin... more Vagueness is a pervasive feature of natural language, but indeed one that is troubling for leading theories in semantics and language evolution. We focus here on the latter, addressing the challenge of how to account for the emergence of vague meanings in signaling game models of language evolution.

Are some identity statements vague for ontic reasons? Are some contingentidentity statements true... more Are some identity statements vague for ontic reasons? Are some contingentidentity statements true? Is there a notion of relative identity such that two things are identical relative to one sortal, but not with respect to another? I don't know. What I do know, though, is that all these claims can be made true, and are all consistent with Leibniz' law being a validity. I show how this is possible by making use of recent ideas for the modeling of vagueness; one that accepts the tolerance principle as a validity. I will show that being tolerant about the notion of consequence allows (though not forces) one to be tolerant about identity as well. * I would like to thank Pablo Cobreros, Paul Egré and Dave Ripley. In our joint work we developped our non-transitive analysis of vagueness and truth. Together we also published a paper on ontic vagueness (Cobreros et al, 2013), of which a slightly different version of current paper was actually a (too long) early draft. Especially discussions with Pablo Cobreros helped me to (hopefully) better represent some of the ideas in this paper. I would also like to thank Manfred Kupffer for his useful comments on this paper. Finally, I would like to thank Ede Zimmermann for the many discussions we had during the time I was his PhD student on issues related to the ones dealt with in this paper.

Proceedings of Sinn und Bedeutung, 2007

European Conference on Artificial Intelligence, 2016

What is the influence of the diversity of the targeted audience on how and what is communicated? ... more What is the influence of the diversity of the targeted audience on how and what is communicated? Although Gricean pragmatics studies the effect of context on what is being communicated, the question how things are communicated is mostly ignored. Moreover, the impact of the size (and thus expected diversity) of the targeted audience is typically not addressed at all. In this paper we will study these questions making use of game theory, the theory of rational interaction. In particular we will argue he above questions can be addressed making use of insights gathered on the equilibria solutions of the Stag Hunt game.

De Gruyter eBooks, Feb 27, 2008

Most work in 'evolutionary linguistics' seeks to motivate the emergence of linguistic universals.... more Most work in 'evolutionary linguistics' seeks to motivate the emergence of linguistic universals. Although the search for universals never played a major role in semantics, a number of such universals have been proposed concerning connectives, property and preposition denoting expressions, and quantifiers. In this paper we suggest some evolutionary motivations for these proposed universals using game theory. * This paper was presented at the Blankensee conference in Berlin and at the first Scottish-Dutch workshop on Language Evolution, both in the summer in 2005. I would like to thank the organizers of those workshops and the participants for their comments. In particular, I would like to thank Bernhard Schröder for discussions on section 3.2 of this paper, and Gerhard Jäger, Samson de Jager, and an anonymous reviewer for their comments on an earlier version of this paper.

Lecture Notes in Computer Science, 2010

In this paper syllogistic logic is extended first to full propositional logic, and then an intere... more In this paper syllogistic logic is extended first to full propositional logic, and then an interesting fragment of predicate logic that includes relations.

An evolutionary perspective on signaling games is adopted to explain some semantic universals con... more An evolutionary perspective on signaling games is adopted to explain some semantic universals concerning truth-conditional connectives; property denoting expressions, and generalized quantifiers. The question to be addressed is: of the many meanings of a particular type that can be expressed, why are only some of them expressed in natural languages by 'simple' expressions?

Lecture Notes in Computer Science, 2011

... He is especially interested in examples involving preference statements as in: (6) Common con... more ... He is especially interested in examples involving preference statements as in: (6) Common context: Peter can only afford cheap wine. Peter: Where can I buy red wine? Bob: At the Wine Centre. +> Peter can buy red wine at a low price at the Wine Centre. Page 10. ...

Lecture Notes in Computer Science, 2015

How can one influence the behavior of others? What is a good persuasion strategy? It is obviously... more How can one influence the behavior of others? What is a good persuasion strategy? It is obviously of great importance to determine what information best to provide and also how to convey it. To delineate how and when manipulation of others can be successful, the first part of this chapter reviews basic findings of decision and game theory on models of strategic communication. But there is also a social aspect to manipulation, concerned with determining who we should address so as best to promote our opinion in a larger group or society as a whole. The second half of this chapter therefore looks at a novel extension of DeGroot's [19] classical model of opinion dynamics that allows agents to strategically influence some agents more than others. This side-by-side investigation of psychological and social aspects enables us to reflect on the general question what a good manipulation strategy is. We submit that successful manipulation requires exploiting critical weaknesses, such as limited capability of strategic reasoning, limited awareness, susceptibility to cognitive biases or to potentially indirect social pressure.

We give derivations of two formal models of Gricean Quantity implicature and strong exhaustivity ... more We give derivations of two formal models of Gricean Quantity implicature and strong exhaustivity in bidirectional optimality theory and in a signalling games framework. We show that, under a unifying model based on signalling games, these interpretative strategies are game-theoretic equilibria when the speaker is known to be respectively minimally and maximally expert in the matter at hand. That is, in this framework the optimal strategy for communication depends on the degree of knowledge the speaker is known to have concerning the question she is answering. In addition, and most importantly, we give a game-theoretic characterisation of the interpretation rule Grice (formalising Quantity implicature), showing that under natural conditions this interpretation rule occurs in the unique equilibrium play of the signalling game.

One of the traditional pragmatic approaches to vagueness suggests that there needs to be a signif... more One of the traditional pragmatic approaches to vagueness suggests that there needs to be a significant gap between individuals or objects that can be described using a vague adjective like tall and those that cannot. In contrast, intuitively, an explicit comparative like taller does not require fulfillment of the gap requirement. Our starting point for this paper is the consideration that people cannot make precise measures under time pressure and their ability to discriminate approximate heights (or other values) obeys Weber's law. We formulate and experimentally test three hypotheses relating to the difference between positive and comparative forms of the vague adjectives, gap requirement, and Weber's law. In two experiments, participants judged appropriateness of usage of positive and comparative forms of vague adjectives in a sentence-picture verification task. Consequently, we review formal analysis of vagueness using weak orders and semi-orders and suggest adjustments based on the experimental results and properties of Weber's law. * Thanks to the Dutch NWO gravitation project Language in Interaction, the ESSENCE Marie Curie Initial Training Network, and the project 'Logicas no-transitivas. Una nueva aproximacion a las paradojas' for financially supporting this project. The authors also thank Nicole Standen-Mills for professional proofreading. John Mary According to Kennedy's (2011) intuition, this picture allows us to say (1-a). At the same time, his intuition is that (1-b) is false. (1) a. John is taller than Mary. b. Compared to Mary, John is tall, but compared to John, Mary is not tall. Kennedy proposes that whereas for the truth of the explicit comparative (1-a) any (directly or indirectly observable) bit of John's height that exceeds Mary's suffices, there should be a significant gap between the heights of John and Mary for the implicit comparative (1-b) to be true. According to Kennedy (2011), such a significant gap is also required to make the positive sentence (2) true with respect to an implicit comparison class: (2) John is tall. As it turns out, Kennedy's intuition concerning (2) fits well with a pragmatic approach towards clustering proposed by various philosophers to (dis)solve the Sorites paradox. The pragmatic gap requirement We can divide people into those that are tall and those that are not. How do we do so? What is the criterion? According to the most obvious solution, everybody is tall whose height is above a certain cutoff-point, where every bit of height suffices. But that gives rise to several questions: (i) How do we determine the cutoff-point? Is it the mean height of the relevant persons, the median height, or something else? 1 (ii) How does this proposal account for the intuition that some people are borderline cases of tall people? (iii) Doesn't this presuppose that we need to be able to measure people's height before we can classify people as tall, and isn't that problematic? Suppose we have settled question (i). How, then to account for borderline cases? A natural proposal would have it that those individuals are borderline tall for which we cannot determine whether they are above or below the cutoff-point. This could be because our measurement is in many cases imprecise. But once we allow for this, we immediately get into

Springer eBooks, 2014

Properties as set of individuals, or of features? Worlds, or propositions? Time-points, or events... more Properties as set of individuals, or of features? Worlds, or propositions? Time-points, or events? Preference, or choice? Natural kinds, or similarity? In modern analytic philosophy it is standard to take (i) individuals as basic, and properties as defined in terms of them; (ii) worlds as basic, and propositions as defined in terms of them; (iii) time-points as basic, and intervals as constructions out of them; (iv) preference as basic, and optimal choice as defined in terms of them; and (v) natural kinds as basic, and similarities as defined in terms of them. In this paper we show that in all cases the other direction is possible as well. Most of the constructions used are well-known. But by putting them collectively on the table we hope to show that the constructions have something in common, and that it is not always clear which perspective is ontologically less committing.

Linguistics and Philosophy, Jul 23, 2019

Cimpian et al. (2010) observed that we accept generic statements of the form 'Gs are f ' on relat... more Cimpian et al. (2010) observed that we accept generic statements of the form 'Gs are f ' on relatively weak evidence, but that if we are unfamiliar with group G and we learn a generic statement about it, we still treat it inferentially in a much stronger way: (almost) all Gs are f. This paper makes use of notions like 'representativeness', 'contingency' and 'relative difference' from (associative learning) psychology to provide a uniform semantics of generics that explains why people accept generics based on weak evidence. The spirit of the approach has much in common with Leslie's cognitionbased ideas about generics, but the semantics will be grounded on a strengthening of Cohen's (1999) relative readings of generic sentences. In contrast to Leslie and Cohen, we propose a uniform semantic analysis of generics. The basic intuition is that a generic of the form 'Gs are f ' is true because f is typical for G, which means that f is valuably associated with G. We will make use of Kahneman and Tversky's Heuristics and Biases approach, according to which people tend to confuse questions about probability with questions about representativeness, to explain pragmatically why people treat many generic statements inferentially in a much stronger way.

Communications in computer and information science, 2016

It is well-known that in combination with further premises that look less controversial, the tole... more It is well-known that in combination with further premises that look less controversial, the tolerance principle-the constraint that if P a holds, and a and b are similar in P-relevant respects, P b holds as well-leads to contradiction, namely to the sorites paradox. According to many influential views of the sorites paradox (e.g. Williamson 1994), we therefore ought to reject the principle of tolerance as unsound. There are reasons to think of such a view as too drastic and as missing out on the role that such a principle plays in categorization and in ordinary judgmental and inferential practice. Taking a different perspective, the tolerance principle ought not to be discarded that fast, even when viewed normatively. Instead, it corresponds to what might be called a soft constraint, or a default, namely a rule that we can use legitimately in reasoning, but that must be used with care. One family of approaches represents the tolerance principle by a certain conditional sentence, of the form: P a ∧ a ∼ P b → P b, and bestows special properties to the conditional to turn it into a soft constraint. One natural option is to use fuzzy logic, where v M (A) can be anywhere in [0, 1] and v M (A → B) = Min{1, 1 − v M (A) + v M (B)}. One can demand that the tolerance conditional may never have a value below 1 − ε for some small ε. Given an appropriate sorites sequence, it will be possible to have: v M (P a 1 → P a 2) = 1−ε, v M (P a 2 → P a 3) = 1 − ε, without having v M (P a 1 → P a 3) = 1 − ε. A different option is to treat the tolerance conditional as expressing a defeasible rule (like when '→' expresses a counterfactual conditional). Say that P a ∧ a ∼ P b → P b is true provided P b is true in all 'optimal' (P a ∧ a ∼ P b)worlds. Call a world (P a ∧ a ∼ P b)-optimal if a is P-similar to b but is not close to a borderline case of P. From P a ∧ a ∼ P b, P a ∧ a ∼ P b → P b, it need not follow that P b, since a world may satisfy P a ∧ a ∼ P b without being Except for the last section, this paper is an abridged version of a longer paper entitled "The Tolerance Principle: Nontransitive Reasoning or Nonmonotonic Reasoning?". We are indebted to two anonymous reviewers for helpful comments.

Axiomathes, Apr 25, 2020

According to Adams (Inquiry 8:166-197, 1965), the acceptability of an indicative conditional goes... more According to Adams (Inquiry 8:166-197, 1965), the acceptability of an indicative conditional goes with the conditional probability of the consequent given the antecedent. However, some conditionals seem to be inappropriate, although their corresponding conditional probability is high. These are cases with a missing link between antecedent and consequent. Other conditionals are appropriate even though the conditional probability is low. Finally, we have the so-called biscuit conditionals. In this paper we will generalize analyses of Douven (Synthese 164:19-44, 2008) and others to account for the appropriateness of conditionals in terms of evidential support. Our generalization involves making use of Value, or intensity. We will show how this generalization helps to account for biscuit conditionals and conditional threats and promises. Finally, a link is established between this analysis of conditionals and an analysis of generic sentences.

Springer eBooks, 2014

Venn diagrams are standardly used to give a semantics for Syllogistic reasoning. This interpretat... more Venn diagrams are standardly used to give a semantics for Syllogistic reasoning. This interpretation is extensional. Leibniz, however, preferred an intensional interpretation, according to which a singular and universal sentence is true iff the (meaning of) the predicate is contained in the (meaning of) the subject. Although Leibniz’s preferred interpretation played a major role in his philosophy (in Leibniz [16] he justifies his metaphysical ‘Principle of Sufficient Reason’ in terms of it) he was not able to extend his succesfull intensional interpretation (making use of characteristic numbers) without negative terms to one where also negative terms are allowed. The goal of this paper is to show how syllogistic reasoning with complex terms can be given a natural set theoretic ‘intensional’ semantics, where the meaning of a term is not defined in terms of individuals. We will make use of the ideas behind van Fraassen’s [6, 7] hyperintensional semantics to account for this.

A traditional issue in the analysis of comparatives is whether or not degrees are essential. In t... more A traditional issue in the analysis of comparatives is whether or not degrees are essential. In the first part of this paper I discuss the traditional analyses that account for comparatives with (Seuren, von Stechow) and without (Klein) degrees, and remind the reader that these are very similar to each other. A more recent issue is how to account for quantifiers in the than-clause. The traditional analyses account well for Negative Polarity Items in comparative clauses, but have problems with conjunctive quantifiers. The strength of the proposals of Larson (1988) and Schwarzchild & Wilkinson (2002), on the other hand, goes exactly in the opposite direction. I will discuss two types of strategies so as to account for both types of quantifiers: (i) one based on the traditional analysis, but by making use of more coarse-grained models or of intervals, (ii) one where comparatives are taken to be ambiguous between the traditional reading and the Larson-reading, and where the actual reading is selected with the help of the strongest meaning hypothesis. 2 The traditional analyses of comparatives There exist two major types of approaches to the analysis of gradable adjectives: comparison class approaches and degree-based approaches. In this section I sketch the traditional approaches along these lines, and show how close they are to each other. Intuitively, John can be counted as tall when we compare him with other men, but not tall when we compare him with (other) basketball players. Thus, whether someone of 1.80 meters is tall or not is context dependent. Wheeler (1972) and Klein (1980) propose that every adjective should be interpreted with respect to a comparison class. A comparison class is just a set of objects/individuals and is contextually given. In particular if the adjective stands alone, we might assume that the contextually given comparison class helps to determine what counts as being tall. Klein (1980) assumed that with respect to a given comparison class, some elements of this set are considered to be definitely tall, some definitely not tall, and the others are borderline cases. The truth of the positive sentence (1) (1) John is tall. * I have presented parts of this paper at various occasions. At a DIP colloquium in Amsterdam, at the CSSP 2007 workshop, and later at talks given in Utrecht and in Tokyo. I would like to thank the audiences for their remarks. I also would like to thank Chris Kennedy and Roger Schwarzchild for discussion. Robert van Rooij depends on the contextually given comparison class: (1) is true in context (or comparison class) c iff John is counted as tall in this class. The proposition expressed by a comparative like (2) is context independent. (2) John is taller than Mary. and the sentence is true iff there is a comparison class according to which John counts as tall, while Mary does not: ∃c[T (j , c) ∧ ¬T (m, c)]. 1 According to the degree-based approaches (e.g.

Lecture Notes in Computer Science, 2011

Vagueness is a pervasive feature of natural language, but indeed one that is troubling for leadin... more Vagueness is a pervasive feature of natural language, but indeed one that is troubling for leading theories in semantics and language evolution. We focus here on the latter, addressing the challenge of how to account for the emergence of vague meanings in signaling game models of language evolution.

Are some identity statements vague for ontic reasons? Are some contingentidentity statements true... more Are some identity statements vague for ontic reasons? Are some contingentidentity statements true? Is there a notion of relative identity such that two things are identical relative to one sortal, but not with respect to another? I don't know. What I do know, though, is that all these claims can be made true, and are all consistent with Leibniz' law being a validity. I show how this is possible by making use of recent ideas for the modeling of vagueness; one that accepts the tolerance principle as a validity. I will show that being tolerant about the notion of consequence allows (though not forces) one to be tolerant about identity as well. * I would like to thank Pablo Cobreros, Paul Egré and Dave Ripley. In our joint work we developped our non-transitive analysis of vagueness and truth. Together we also published a paper on ontic vagueness (Cobreros et al, 2013), of which a slightly different version of current paper was actually a (too long) early draft. Especially discussions with Pablo Cobreros helped me to (hopefully) better represent some of the ideas in this paper. I would also like to thank Manfred Kupffer for his useful comments on this paper. Finally, I would like to thank Ede Zimmermann for the many discussions we had during the time I was his PhD student on issues related to the ones dealt with in this paper.

Proceedings of Sinn und Bedeutung, 2007

European Conference on Artificial Intelligence, 2016

What is the influence of the diversity of the targeted audience on how and what is communicated? ... more What is the influence of the diversity of the targeted audience on how and what is communicated? Although Gricean pragmatics studies the effect of context on what is being communicated, the question how things are communicated is mostly ignored. Moreover, the impact of the size (and thus expected diversity) of the targeted audience is typically not addressed at all. In this paper we will study these questions making use of game theory, the theory of rational interaction. In particular we will argue he above questions can be addressed making use of insights gathered on the equilibria solutions of the Stag Hunt game.

De Gruyter eBooks, Feb 27, 2008

Most work in 'evolutionary linguistics' seeks to motivate the emergence of linguistic universals.... more Most work in 'evolutionary linguistics' seeks to motivate the emergence of linguistic universals. Although the search for universals never played a major role in semantics, a number of such universals have been proposed concerning connectives, property and preposition denoting expressions, and quantifiers. In this paper we suggest some evolutionary motivations for these proposed universals using game theory. * This paper was presented at the Blankensee conference in Berlin and at the first Scottish-Dutch workshop on Language Evolution, both in the summer in 2005. I would like to thank the organizers of those workshops and the participants for their comments. In particular, I would like to thank Bernhard Schröder for discussions on section 3.2 of this paper, and Gerhard Jäger, Samson de Jager, and an anonymous reviewer for their comments on an earlier version of this paper.

Lecture Notes in Computer Science, 2010

In this paper syllogistic logic is extended first to full propositional logic, and then an intere... more In this paper syllogistic logic is extended first to full propositional logic, and then an interesting fragment of predicate logic that includes relations.

An evolutionary perspective on signaling games is adopted to explain some semantic universals con... more An evolutionary perspective on signaling games is adopted to explain some semantic universals concerning truth-conditional connectives; property denoting expressions, and generalized quantifiers. The question to be addressed is: of the many meanings of a particular type that can be expressed, why are only some of them expressed in natural languages by 'simple' expressions?

Lecture Notes in Computer Science, 2011

... He is especially interested in examples involving preference statements as in: (6) Common con... more ... He is especially interested in examples involving preference statements as in: (6) Common context: Peter can only afford cheap wine. Peter: Where can I buy red wine? Bob: At the Wine Centre. +> Peter can buy red wine at a low price at the Wine Centre. Page 10. ...

Lecture Notes in Computer Science, 2015

How can one influence the behavior of others? What is a good persuasion strategy? It is obviously... more How can one influence the behavior of others? What is a good persuasion strategy? It is obviously of great importance to determine what information best to provide and also how to convey it. To delineate how and when manipulation of others can be successful, the first part of this chapter reviews basic findings of decision and game theory on models of strategic communication. But there is also a social aspect to manipulation, concerned with determining who we should address so as best to promote our opinion in a larger group or society as a whole. The second half of this chapter therefore looks at a novel extension of DeGroot's [19] classical model of opinion dynamics that allows agents to strategically influence some agents more than others. This side-by-side investigation of psychological and social aspects enables us to reflect on the general question what a good manipulation strategy is. We submit that successful manipulation requires exploiting critical weaknesses, such as limited capability of strategic reasoning, limited awareness, susceptibility to cognitive biases or to potentially indirect social pressure.