We present the propositional logic LEC for the two epistemic modalities of current and stable knowledge used by an agent who systematically enriches his language. A change in the linguistic resources of an agent as a result of certain cognitive processes is something that commonly happens. Our system is based on the logic LC intended to formalize the idea that the occurrence of changes induces the passage of time. Here, the primitive operator C read as: it changes that, defines the temporal succession of states of the world. The notion of current knowledge concerns variable components of the world and it may change over time. We represent it by the primitive operator k read as: the agent currently knows that, and assume that it has S5 properties. The second type of knowledge, symbolized by the primitive operator K read as: the agent stably knows that, relates to constant components of the world and it does not change. As a result of the axiomatic entanglement of C, K and k we show that stable knowledge satisfies axioms of S4.3. K and k modalities are not mutually definable, stable knowledge implies the current one and if the latter never changes, then it comes to be stable. The combination of K and k with the idea of an expanding language allows questioning of the so-called perfect recall principle. It cannot be maintained for both types of knowledge just because of changes in the vocabulary of the agent and possibly the growing spectrum of possible states of the world. We interpret LEC in the semantics of histories of epistemic changes and show that it is complete. Finally, we compare our logic with selected epistemic logics based on the concept of linear discrete time.
{"title":"The Modal Logic LEC for Changing Knowledge, Expressed in the Growing Language","authors":"Marcin Łyczak","doi":"10.12775/LLP.2020.012","DOIUrl":"https://doi.org/10.12775/LLP.2020.012","url":null,"abstract":"We present the propositional logic LEC for the two epistemic modalities of current and stable knowledge used by an agent who systematically enriches his language. A change in the linguistic resources of an agent as a result of certain cognitive processes is something that commonly happens. Our system is based on the logic LC intended to formalize the idea that the occurrence of changes induces the passage of time. Here, the primitive operator C read as: it changes that, defines the temporal succession of states of the world. The notion of current knowledge concerns variable components of the world and it may change over time. We represent it by the primitive operator k read as: the agent currently knows that, and assume that it has S5 properties. The second type of knowledge, symbolized by the primitive operator K read as: the agent stably knows that, relates to constant components of the world and it does not change. As a result of the axiomatic entanglement of C, K and k we show that stable knowledge satisfies axioms of S4.3. K and k modalities are not mutually definable, stable knowledge implies the current one and if the latter never changes, then it comes to be stable. The combination of K and k with the idea of an expanding language allows questioning of the so-called perfect recall principle. It cannot be maintained for both types of knowledge just because of changes in the vocabulary of the agent and possibly the growing spectrum of possible states of the world. We interpret LEC in the semantics of histories of epistemic changes and show that it is complete. Finally, we compare our logic with selected epistemic logics based on the concept of linear discrete time.","PeriodicalId":43501,"journal":{"name":"Logic and Logical Philosophy","volume":" ","pages":"1"},"PeriodicalIF":0.5,"publicationDate":"2020-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42046368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Computation and Indispensability","authors":"J. Ketland","doi":"10.12775/llp.2020.011","DOIUrl":"https://doi.org/10.12775/llp.2020.011","url":null,"abstract":"","PeriodicalId":43501,"journal":{"name":"Logic and Logical Philosophy","volume":"1 1","pages":"1"},"PeriodicalIF":0.5,"publicationDate":"2020-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41437215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Standard deontic logic (SDL) is defined on the basis of possible world semantics and is a logic of alethic-deontic modalities rather than deontic modalities alone. The interpretation of the concepts of obligation and permission comes down exclusively to the logical value that a sentence adopts for the accessible deontic alternatives. Here, we set forth a different approach, this being a logic which additionally takes into consideration whether sentences stand in relation to the normative system or to the system of values under which we predicate the deontic qualifications. By taking this aspect into account, we arrive at a logical system which preserves laws proper to a deontic logic but where the standard paradoxes of deontic logic do not arise. It is a logic of strictly-deontic modalities DR.
{"title":"On Logic of Strictly-Deontic Modalities. A Semantic and Tableau Approach","authors":"Tomasz Jarmużek, Mateusz Klonowski","doi":"10.12775/llp.2020.010","DOIUrl":"https://doi.org/10.12775/llp.2020.010","url":null,"abstract":"Standard deontic logic (SDL) is defined on the basis of possible world semantics and is a logic of alethic-deontic modalities rather than deontic modalities alone. The interpretation of the concepts of obligation and permission comes down exclusively to the logical value that a sentence adopts for the accessible deontic alternatives. Here, we set forth a different approach, this being a logic which additionally takes into consideration whether sentences stand in relation to the normative system or to the system of values under which we predicate the deontic qualifications. By taking this aspect into account, we arrive at a logical system which preserves laws proper to a deontic logic but where the standard paradoxes of deontic logic do not arise. It is a logic of strictly-deontic modalities DR.","PeriodicalId":43501,"journal":{"name":"Logic and Logical Philosophy","volume":"29 1","pages":"335-380"},"PeriodicalIF":0.5,"publicationDate":"2020-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45092785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
. The purpose of this paper is to provide a new system of logic for existence and essence, in which the traditional distinctions between essential and accidental properties, abstract and concrete objects, and actually existent and possibly existent objects are described and related in a suit-able way. In order to accomplish this task, a primitive relation of essential identity between different objects is introduced and connected to a first order existence property and a first order abstractness property. The basic idea is that possibly existent objects are completely determinate and that essentially identical objects are just different individuations of the same individual essence. Accordingly, essential properties are defined as properties that are invariant with respect to this kind of identity, while abstract objects are determined by being characterized by essential properties only. Once such ideas are implemented, a number of classical intuitions about objects, their essence, and their way of existence can be consistently interpreted.
{"title":"A Classical Logic of Existence and Essence","authors":"S. Galvan, A. Giordani","doi":"10.12775/llp.2020.009","DOIUrl":"https://doi.org/10.12775/llp.2020.009","url":null,"abstract":". The purpose of this paper is to provide a new system of logic for existence and essence, in which the traditional distinctions between essential and accidental properties, abstract and concrete objects, and actually existent and possibly existent objects are described and related in a suit-able way. In order to accomplish this task, a primitive relation of essential identity between different objects is introduced and connected to a first order existence property and a first order abstractness property. The basic idea is that possibly existent objects are completely determinate and that essentially identical objects are just different individuations of the same individual essence. Accordingly, essential properties are defined as properties that are invariant with respect to this kind of identity, while abstract objects are determined by being characterized by essential properties only. Once such ideas are implemented, a number of classical intuitions about objects, their essence, and their way of existence can be consistently interpreted.","PeriodicalId":43501,"journal":{"name":"Logic and Logical Philosophy","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2020-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42928305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Chisholm's Modal Paradox(es) and Counterpart Theory 50 Years On","authors":"M. Ramachandran","doi":"10.12775/llp.2020.008","DOIUrl":"https://doi.org/10.12775/llp.2020.008","url":null,"abstract":"","PeriodicalId":43501,"journal":{"name":"Logic and Logical Philosophy","volume":" ","pages":"1"},"PeriodicalIF":0.5,"publicationDate":"2020-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46892939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Self-knowledge (SK) is a natural ability of the human cognitive system and is defined as a complex re-representation of knowledge subject has about her own internal states. It is composed of two basic representations: the representation of I and the representation of the experienced state. SK has a propositional (i.e. language-like) form and can be expressed in the form of self-reports like “I believe that I believe that p”. It has then the form of a second-order belief which, as a re-representation, generates the following problem concerning false representations: if the first-order representations of the I or of experienced states can be false like in cases of self-illusions or disorders like somatoparaphrenia, then how can error in self-cognition inherited by the re-representation (i.e. by SK) be avoided? I claim that the re-representational model of SK is a useful but artificial tool for the description of the components of SK; however, it is misleading to think of it as capturing the truth about SK. I propose here a representational model of SK which reduces those beliefs constituting SK to first-order beliefs which are sufficient as constituents of SK.
{"title":"False Re-Representations in Self-Knowledge","authors":"A. Pacholik-Zuromska","doi":"10.12775/llp.2020.007","DOIUrl":"https://doi.org/10.12775/llp.2020.007","url":null,"abstract":"Self-knowledge (SK) is a natural ability of the human cognitive system and is defined as a complex re-representation of knowledge subject has about her own internal states. It is composed of two basic representations: the representation of I and the representation of the experienced state. SK has a propositional (i.e. language-like) form and can be expressed in the form of self-reports like “I believe that I believe that p”. It has then the form of a second-order belief which, as a re-representation, generates the following problem concerning false representations: if the first-order representations of the I or of experienced states can be false like in cases of self-illusions or disorders like somatoparaphrenia, then how can error in self-cognition inherited by the re-representation (i.e. by SK) be avoided? I claim that the re-representational model of SK is a useful but artificial tool for the description of the components of SK; however, it is misleading to think of it as capturing the truth about SK. I propose here a representational model of SK which reduces those beliefs constituting SK to first-order beliefs which are sufficient as constituents of SK.","PeriodicalId":43501,"journal":{"name":"Logic and Logical Philosophy","volume":"29 1","pages":"463-481"},"PeriodicalIF":0.5,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43765828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sorites, Curry and Suitable Models","authors":"B. Ré, Paula Teijeiro","doi":"10.12775/llp.2020.006","DOIUrl":"https://doi.org/10.12775/llp.2020.006","url":null,"abstract":"","PeriodicalId":43501,"journal":{"name":"Logic and Logical Philosophy","volume":"1 1","pages":"1"},"PeriodicalIF":0.5,"publicationDate":"2020-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66615762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Malinowski, K. Pietrowicz, Joanna Szalacha-Jarmużek
In 1947 Jerzy Łoś proposed a positional logic based on the realization operator. We follow his work and present it in the context of fundamental challenges of sociology such as the complexity of social reality and reflexivity of social agents. The paper is an outline of the general concept, as it opens a discussion and sets ground for future elaborations. In this paper, we are considering the concept according to which the expressions put forward by Łoś’s system might be indexed not only by spatial and temporal variables, but also by social contexts. And as such Łoś’s system might be a significant improvement, a valuable addition for social simulations and computational sociology, which use multi-agent systems and agent-based modeling. We consider how Łoś’s operator might be useful for these disciplines, as it gives a chance to combine of formalization with the humanistic coefficient, which represents the issues of complexity and reflexivity of social agents.
{"title":"Logic of Social Ontology and Łoś’s Operator","authors":"J. Malinowski, K. Pietrowicz, Joanna Szalacha-Jarmużek","doi":"10.12775/llp.2020.005","DOIUrl":"https://doi.org/10.12775/llp.2020.005","url":null,"abstract":"In 1947 Jerzy Łoś proposed a positional logic based on the realization operator. We follow his work and present it in the context of fundamental challenges of sociology such as the complexity of social reality and reflexivity of social agents. The paper is an outline of the general concept, as it opens a discussion and sets ground for future elaborations. In this paper, we are considering the concept according to which the expressions put forward by Łoś’s system might be indexed not only by spatial and temporal variables, but also by social contexts. And as such Łoś’s system might be a significant improvement, a valuable addition for social simulations and computational sociology, which use multi-agent systems and agent-based modeling. We consider how Łoś’s operator might be useful for these disciplines, as it gives a chance to combine of formalization with the humanistic coefficient, which represents the issues of complexity and reflexivity of social agents.","PeriodicalId":43501,"journal":{"name":"Logic and Logical Philosophy","volume":"29 1","pages":"239-258"},"PeriodicalIF":0.5,"publicationDate":"2020-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42911455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}