The Logic and Language research programme encompasses a broad range of topics in (mostly formal) philosophy, crossing the boundaries of a number of areas ranging from empirical linguistics, epistemology, ontology, philosophy of science to cognitive science. Major themes are interpretation of natural language, human reasoning, intelligent interaction and informational correlations. The methods we use for investigation are mostly based on logical and philosophical analysis. Empirical ratification of analytical work is our main ambition and touchstone for success in the work of empirical linguistics. Other parameters such as coherence, consistency and explanatory power play an important role when designing our theoretical models. Our research strategy is non-monolithic, allowing for different approaches, but demanding philosophical reflection and internal and external debate.
In our investigations on interpretation we follow several intertwined research lines, using different instruments from a logical toolbox, of which intensional logic, epistemic logic, many-valued logic, non-monotonic logic, dynamic logic, game and decision theory, formal learning theory and topology are prominent parts. To highlight just one example, let us mention the integration of semantics and pragmatics. The binding force is the conviction that interpretation should be studied as a dynamic cognitive process that is embedded both in social practices and the external environment. This view differs markedly from the more traditional one, according to which a theory of interpretation assigns 'static' semantic contents to linguistic structures independently of their use. Hence, the integration of semantics and pragmatics is a dominant longer term research aim.
This view on how logic and language connect, has obvious historical roots, e.g., the writings of Aristotle, Leibniz, Kant, Bolzano, Frege, Wittgenstein, Quine, and Montague. Systematic and historical study of the works of these intellectual forebears forms a substantial part of the programme, also to stimulate critical reflection on current systematic research and inspire debate on our current positions.
The various systematic investigations concentrate on empirical phenomena that are intrinsically related to the way in which information is structured in the context of conversations. Prominent examples are the interplay between mood and modality, questions and imperatives, implicatures and presuppositions.
In our investigations on reasoning we want to show that logical languages can be fruitfully used as high-level specifications of cognitive functions, and that contrary to current opinions in cognitive science mathematical logic can be used in explaining human reasoning behaviour. To achieve these aims logical and computational models are paired with methods from empirical psychology and neuro-science in an innovative way. In addition to the research on reasoning, other issues in the domain between cognitive science and philosophy, such as the representation of time and causality, ontology, know-how and everyday expertise, are investigated.
Our basic outlook on interpretation as a cognitive process embedded in social practices, makes a strong bond between interpretation and reason(ing). Ultimately, we want to explain the procedures of the production and interpretation of speech as a natural evolution of rational human behaviour.
In relation to epistemology and rational agency, we build logical models with the aim of clarifying a variety of philosophical concepts that are currently used in relation to the different epistemic and doxastic attitudes that an agent may posses. In addition to modeling single agent attitudes, we focus as well on various interactive scenarios in which complex forms of correlated information change play a crucial role.
The success of all our investigations relies on the combination of insights and techniques that may come from a range of research domains, including logic, semantics, pragmatics, formal epistemology, belief revision theory, formal learning theory, ontology and philosophy of science. This highlights the diversity of our overall programme as well as the strong interdisciplinary connections that exist both within our programme itself and in relation to the other programmes of the ILLC.