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:: Calls :: Workshop on Language and metalanguage, logic and meta-logic. Revisiting Tarski’s hierarchy,  to take place on May 19-20 at the Université catholique de Louvain (UCL). Deadline for papers: 1 February. Targeted towards young researchers.

Contributions of young researchers (without PhD degree or max. 5 years after obtaining PhD degree) in English or French are welcome. Notification of acceptance: February 15, 2016.

Please submit your abstract of approximately 500 words to: peter.verdee@uclouvain.be

Invited Speakers (on condition of approval of funding application)

ACHOURIOTI Dora, Universiteit van Amsterdam (ILLC), Amsterdam, Netherlands
RUSSELL Gillian, University of North Carolina, Chapel Hill, NC, USA
VENTURI Giorgio, State University of Campinas (UNICAMP), Campinas, SP, Brazil
WEBER Zach, University of Otago, Dunedin, Otago, New-Zealand
DE BRABANTER Philippe, Université Libre de Bruxelles, Brussels, Belgium
DEGAUQUIER Vincent, Université Namur, Namur, Belgium
RICHARD Sébastien, Université Libre de Bruxelles, Brussels, Belgium
URBANIAK Rafal, Ghent University, Ghent, Belgium and University of Gdansk, Gdansk, Poland


Ever since the work of Alfred Tarski we have known that trivializing paradoxes arise when one designs a precise language that is able to express at the same time the object theory and the metatheory of a certain domain. As a solution, Tarski suggested a strict hierarchy of languages in which every language can only talk about the language immediately below it in the hierarchy. Although this works as a technical solution, it is rather artificial and remote from our intuitions about natural language.

Since Tarski’s results, logic, philosophy of language and mathematics have changed quite a bit. Nowadays we have a multitude of non-classical logical systems that can prevent the paradoxes from popping up or from destroying all meaning. There are well-established mathematical tools to carefully deal with the possibility of reasoning about the metatheory of a foundational theory (“forcing” in set theory, category theory, consistency strength). Ways of dealing sensibly with non-stratified full comprehension in mathematics have been proposed. Sophisticated grounding and revision techniques for self-referential truth have been developed. Formal tools have been devised to better understand natural language. People are trying to emancipate themselves from the norm that urges us to use a classical metatheory.

Specialists in the relevant fields are invited to present their own current research (on any related topic) and, from that perspective, reflect upon the implications of their work for at least one of the following issues:

* Is the distinction necessary, desirable, natural?
* Importance of a clear meta/object-language distinction for truth theory
* Importance of a clear meta/object-language distinction for metamathematics
* Importance of a clear meta/object-language distinction for the famous foundational theorems: Gödel (incompleteness), Löwenheim-Skolem (for each cardinality a model), Cohen (forcing)

* How can one formalize metalanguage?
* How to avoid infinite regress (object, meta, meta-meta, meta-meta-meta…) when trying to make a language precise?
* Should the same logic be used at the object level as at the metalevel?
* Is it reasonable to assume a shared natural metalanguage?
* Is it possible/useful to unify (meta-)languages and to reduce one to another language?

* Category/type/set theory as unifying metalanguage of mathematics and computer science
* Universality of languages
* Logical pluralism


Bruno Leclercq, ULg, Liège, Belgium
Peter Verdée, UCL, Louvain-la-Neuve

For more information: http://perso.uclouvain.be/peter.verdee/metalang2016