Periodic Reporting for period 4 - EXPRESS (From the Expression of Disagreeement to New Foundations for Expressivist Semantics)
Reporting period: 2022-08-01 to 2023-01-31
Disagreement is a pervasive feature of human life. Democrats and Republicans disagree over whom the next US President should be. Public opinion is divided over which measures to take in the face of climate change. Citizens of the United Kingdom disagree over whether leaving the EU will negatively impact their nation’s economy.
Disagreement finds linguistic expression in the speech-act of rejection (also called denial). Suppose you say that Amsterdam is in Belgium. In so doing, you perform an assertion—a speech-act in which something is claimed to be the case. I can express my dissent with you by responding ‘no’, thereby rejecting your assertion.
In the study of human language, the speech-act of assertion has taken centre stage. Philosophers have formulated several competing accounts of assertion. Linguists have constructed detailed models of the conversational effects of assertion. Logicians have investigated the mathematical properties of systems involving assertions.
By contrast, the speech-act of rejection has been largely neglected, and its investigation has traditionally been regarded as a chapter in the study of assertion. The EXPRESS project aimed to articulate a full-fledged theory of rejection which is philosophically and linguistically sound. The importance of this endeavour cannot be overestimated: without such a theory of rejection, we cannot properly understand the way disagreement is expressed and our understanding of the mechanisms of conversation—in which rejection plays a central role—is severely limited. Once the importance of rejection is appreciated, it becomes pressing to understand what its logic is, in the same way as much effort has been put into studying the logic of assertion. The project therefore aimed to develop a logic of rejection faithful to the linguistic phenomena.
The project distinguished between weak ('Will Trump or Biden win the election? No, neither will win!) and strong ('Will Trump or Biden win the election? No, Jorgensen will win!) forms of rejection and developed a theory of these forms of rejection based on their effect on the conversation and the attitudes they express. The project went on to develop a logical framework capable of dealing with various forms of rejection, as well as various forms of assertion and other speech acts. The project then used the theory and logical framework developed to establish a novel approach to natural language semantics, inferential expressivism, which combines elements of the expressivist and inferentialist programmes. The project applied inferential expressivism to a wide range of linguistic phenomena and showed that inferential expressivism retains the key advantages of expressivism and inferentialism whilst addressing their main shortcomings.
Inferential expressivism naturally leads to distinctive hypotheses about language evolution. The project studied these hypotheses using computational modelling techniques, providing a model for the emergence of denial in natural language. This supports an explanation of the universality of negation in human languages based on the structure of conversations.
Disagreement finds linguistic expression in the speech-act of rejection (also called denial). Suppose you say that Amsterdam is in Belgium. In so doing, you perform an assertion—a speech-act in which something is claimed to be the case. I can express my dissent with you by responding ‘no’, thereby rejecting your assertion.
In the study of human language, the speech-act of assertion has taken centre stage. Philosophers have formulated several competing accounts of assertion. Linguists have constructed detailed models of the conversational effects of assertion. Logicians have investigated the mathematical properties of systems involving assertions.
By contrast, the speech-act of rejection has been largely neglected, and its investigation has traditionally been regarded as a chapter in the study of assertion. The EXPRESS project aimed to articulate a full-fledged theory of rejection which is philosophically and linguistically sound. The importance of this endeavour cannot be overestimated: without such a theory of rejection, we cannot properly understand the way disagreement is expressed and our understanding of the mechanisms of conversation—in which rejection plays a central role—is severely limited. Once the importance of rejection is appreciated, it becomes pressing to understand what its logic is, in the same way as much effort has been put into studying the logic of assertion. The project therefore aimed to develop a logic of rejection faithful to the linguistic phenomena.
The project distinguished between weak ('Will Trump or Biden win the election? No, neither will win!) and strong ('Will Trump or Biden win the election? No, Jorgensen will win!) forms of rejection and developed a theory of these forms of rejection based on their effect on the conversation and the attitudes they express. The project went on to develop a logical framework capable of dealing with various forms of rejection, as well as various forms of assertion and other speech acts. The project then used the theory and logical framework developed to establish a novel approach to natural language semantics, inferential expressivism, which combines elements of the expressivist and inferentialist programmes. The project applied inferential expressivism to a wide range of linguistic phenomena and showed that inferential expressivism retains the key advantages of expressivism and inferentialism whilst addressing their main shortcomings.
Inferential expressivism naturally leads to distinctive hypotheses about language evolution. The project studied these hypotheses using computational modelling techniques, providing a model for the emergence of denial in natural language. This supports an explanation of the universality of negation in human languages based on the structure of conversations.
The project developed a full-fledged theory of rejection, expanding and modifying extant models of conversation to take into account the fact that speakers not only assert or accept what is being asserted but often reject. Paying close attention to the linguistic phenomena, we identified and studied weak, moderate and strong forms of assertion and rejection. We then used these weak, moderate and strong forms of assertion and rejection to develop what we call a ‘multilateral logic framework’, a logical framework which has the resources to handle not only assertion (like standard logical systems) but also other speech acts. The mathematical properties of this framework were extensively studied and extensions of the framework involving speech acts other than strong, moderate and weak forms of assertion and rejection were developed.
The project used the theories and logics developed to establish a novel approach to natural language semantics, inferential expressivism, which explains the meaning of an expression in terms of the inferences we draw involving the attitudes we express. This approach combines elements of the expressivist and inferentialist programmes in semantics. We showed that inferential expressivism has the resources to address the main challenges faced by expressivism and inferentialism respectively, in particular the so-called Frege-Geach Problem and the problem of limited applicability. Moreover, we demonstrated the fruitfulness of the inferential expressivist approach by applying it to a wide range of linguistic phenomena including negation, epistemic modals (e.g. expressions such as `might’ in `Elizabeth Warren might win the Democratic primaries’), moral vocabulary (e.g. expressions such as `wrong’), vague expressions (such as `red'), semantic vocabulary (such as 'true'), conditionals and probabilistic operators (e.g. expressions such as 'It is unlikely that Jorgensen will win the presidential elections').
In the context of language evolution, we used game theory and computational techniques to show that the presence of rejection explains the emergence of negation (whose presence is effectively universal in human languages). One key result in this part of the project is the development of a new model of linguistic interactions which we call the Rejection Game.
The interplay between philosophical and linguistic analysis, logical methods and computational techniques proved particularly fruitful. The output of the work includes numerous articles in top logic (Journal of Philosophical Logic, Review of Symbolic Logic), linguistics (Semantics and Pragmatics, Linguistics and Philosophy) and philosophy (Mind, Journal of Philosophy, Philosophical Quarterly, British Journal for the Philosophy of Science, Erkenntnis) journals and a monograph (Oxford University Press). Several events were organized, including a weekly reading group, a seminar with invited speakers, three international workshops and a three-day conference. The project's findings were also advertised on social media, magazines and blogs.
The project used the theories and logics developed to establish a novel approach to natural language semantics, inferential expressivism, which explains the meaning of an expression in terms of the inferences we draw involving the attitudes we express. This approach combines elements of the expressivist and inferentialist programmes in semantics. We showed that inferential expressivism has the resources to address the main challenges faced by expressivism and inferentialism respectively, in particular the so-called Frege-Geach Problem and the problem of limited applicability. Moreover, we demonstrated the fruitfulness of the inferential expressivist approach by applying it to a wide range of linguistic phenomena including negation, epistemic modals (e.g. expressions such as `might’ in `Elizabeth Warren might win the Democratic primaries’), moral vocabulary (e.g. expressions such as `wrong’), vague expressions (such as `red'), semantic vocabulary (such as 'true'), conditionals and probabilistic operators (e.g. expressions such as 'It is unlikely that Jorgensen will win the presidential elections').
In the context of language evolution, we used game theory and computational techniques to show that the presence of rejection explains the emergence of negation (whose presence is effectively universal in human languages). One key result in this part of the project is the development of a new model of linguistic interactions which we call the Rejection Game.
The interplay between philosophical and linguistic analysis, logical methods and computational techniques proved particularly fruitful. The output of the work includes numerous articles in top logic (Journal of Philosophical Logic, Review of Symbolic Logic), linguistics (Semantics and Pragmatics, Linguistics and Philosophy) and philosophy (Mind, Journal of Philosophy, Philosophical Quarterly, British Journal for the Philosophy of Science, Erkenntnis) journals and a monograph (Oxford University Press). Several events were organized, including a weekly reading group, a seminar with invited speakers, three international workshops and a three-day conference. The project's findings were also advertised on social media, magazines and blogs.
By establishing inferential expressivism as a new semantic paradigm, the project brought about ground-breaking results in philosophy, logic and linguistics. In philosophy, the project showed how to address the major challenges faced by expressivism and inferentialism. In logic, it developed and studied the mathematical properties of a new class of formal systems -- multilateral systems. In linguistics, it provided new accounts of a wide range of linguistic phenomena whose analysis is notoriously difficult, including negation, epistemic modals, conditionals, truth and probability operators. In sum, the project provided the foundations for a novel approach to natural language semantics which is philosophically motivated, linguistically and logically grounded, and improves on extant approaches in the way it deals with several logical and linguistic problems. In addition, the project provided novel models of the emergence of certain linguistic expressions bringing together game theory, logic, linguistics and computer simulations.