The 21st Trends in Logic international conference will be held at Ruhr University Bochum, Germany, from December 6-December 8, 2021 under the title “Frontiers of connexive logic”. It is organized by the chairs of Logic and Epistemology and Nonclassical Logic at the Department of Philosophy I of Ruhr University Bochum, in co-operation with Studia Logica.

Modern connexive logic started in the 1960s with seminal papers by Richard B. Angell and Storrs McCall. Connexive logics are orthogonal to classical logic insofar as they validate certain non-theorems of classical logic, namely

• Aristotle's Theses: ~(~A => A), ~(A => ~A)

• Boethius' Theses: (A => B)=> ~(A => ~B), (A => ~B) => ~(A => B)

Systems of connexive logic have been motivated by considerations on a content connection between the antecedent and succedent of valid implications and by applications that range from Aristotle's syllogistic to Categorial Grammar and the study of causal implications. Surveys of connexive logic can be found in:

• S. McCall, "A History of Connexivity", in D.M. Gabbay et al. (eds.), Handbook of the History of Logic. Volume 11. Logic: A History of its Central Concepts, Amsterdam, Elsevier, 2012, pp. 415-449.

• H. Wansing, "Connexive Logic", in Edward N. Zalta (ed.), The Stanford Encyclopedia of Philosophy (Spring 2020 Edition).

There is also a special issue on connexive logics in the IfCoLog Journal of Logics and their Applications based on papers presented during the first workshop. The entire issue is available here.

There is another special issue of Logic and Logical Philosophy based on papers presented during the third workshop. The entire issue is available here.

As we are observing some growing interests in topics related to connexive logics, after six annual workshops, the Trends in Logic XXI aims at discussing directions for future research in connexive logics.

INVITED SPEAKERS:

• Paul Egré (Paris)

• Andrea Iacona (Turin)

• Marko Malink (New York)

• Jacek Malinowski (Warsaw)

• Edwin Mares (Wellington)

• Christopher Martin (Auckland)

• George Metcalfe (Bern)

• Sergei P. Odintsov (Novosibirsk)

• Francesco Paoli (Cagliari)

• Niki Pfeifer (Regensburg)

• Claudio Pizzi (Siena)

• Hans Rott (Regensburg)

PAPER SUBMISSION:

Any papers related to connexive logics are welcome. Topics of interest include (but are not limited to) the following:

• Historical considerations of the notion of connexivity;

• Discussions on the notion of connexive logics;

• Examinations of various systems of connexive logics;

• Relations between connexive logics and other nonclassical logics, such as conditional logics;

• Philosophical implications of connexive logics;

• Discussions on the relation between Experimental philosophy and connexivity.

Moreover, we will have a special session on contra-classical logics, and thus any papers related to contra-classical logics are welcome. Topics of interest include (but are not limited to) the following:

• Historical considerations of contra-classical logics;

• Discussions on the notion of contra-classicality;

• Examinations of various systems of contra-classical logics;

• Relations between contra-classical logics and other nonclassical logics;

• Philosophical implications of contra-classical logics.

Submissions of extended abstracts (up to three pages) should be submitted electronically as pdf documents using the EasyChair submission page at

https://easychair.org/conferences/?conf=trends2021

At least one author of each accepted paper must register for, and attend, the conference to present their work. Full versions of selected papers will be published in a special issue of Studia Logica after an open call for papers (current planned deadline: 31 January, 2022).

IMPORTANT DATES:

Deadline for submission: August 31, 2021 September 14, 2021. [EXTENDED]

Notification of acceptance: September 30, 2021 October 14, 2021.

CONTACT AND FURTHER DETAILS:

Website: https://sites.google.com/view/trendsinlogicxxi/

Please direct all inquiries by email to: trendsinlogicxxi [at] rub [dot] de