Joao Marcos (UFRN) gives a talk at the MCMP Colloquium (5 June, 2014) titled "Logical consequence explicated in terms of cognitive attitudes". Abstract: The received notions of logical consequence, either introduced by semantical means or by way of some convenient proof formalism, or even studied in their own right as abstract relations/operations between sentences or collections of sentences, are often explicated in terms of standard judgments such as assertion and refutation/denial. As a matter of fact, from the semantical viewpoint such judgments are often confused with truth-values. For a fresh view on the matter, we propose substituting judgments by a richer collection of primitive cognitive attitudes concerning acceptance or rejection, by an agent, of a given piece of information, and organize such attitudes into an opposition structure from which we show how to extract a generous bidimensional notion of entailment, henceforth called B-entailment, that generalizes the well-known approaches by Tarski, by Scott, and by

Shoesmith & Smiley ([7]). We study and prove a general characterization result about the underlying abstract consequence relations in terms of a bilattice-based structure of truth-values, show that it extends earlier results by G. Malinowski and S. Frankowski ([6,4]), and show how this connects to older and newer research on the structure of truth-values or of the space of valuations ([2,8,5]). Finally, we also prove a normal form result that shows how the B-entailment formalism is expressive enough so as to define any 4-valued (partial) nondeterministic matrix ([1,3]). This reports on joint work with Carolina Blasio and Carlos Caleiro.

Sander Beckers (Leuven) gives a talk at the MCMP Colloquium (6 November, 2013) titled "Actual causation using CP-logic". Abstract: Since Pearl’s seminal work on providing a formal language for causality, the subject has garnered a lot of interest among philosophers and researchers in artificial intelligence alike. One of the most debated topics in this context regards the notion of actual causation, or token causation, which concerns itself with specific - as opposed to general - causal claims. The search for a proper formal definition of actual causation has evolved into a controversial debate, that is pervaded with ambiguities and confusion. One of the goals of our research is to provide a clear way for comparing competing definitions, by translating the main existing approaches into one formal paradigm, namely CP-logic (Causal Probabilistic logic). Another goal we have is to relate the abstract philosophical discussion to practical applications of causal reasoning. In this talk we shall do so by focusing on the definition(s) offered by Ned Hall (2004, 2007). We will show how his ideas can be expressed in the CP-logic framework, and how this can be seen as an improvement. Further, we shall contrast his definition with our own.

Florian Steinberger (MCMP/LMU) gives a talk at the Workshop on Meaning: Models and Proofs (11-12 Oct, 2013, co-organized by the MCMP and the Arché Research Centre, St Andrews) titled "Understanding and inference".

Alex Yates (Arché) gives a talk at the Workshop on Meaning: Models and Proofs (11-12 Oct, 2013, co-organized by the MCMP and the Arché Research Centre, St Andrews) titled "Truth-conditional Theories of Meaning within Fregean Limits".

Ole T. Hjortland (MCMP/LMU) gives a talk at the Workshop on Meaning: Models and Proofs (11-12 Oct, 2013, co-organized by the MCMP and the Arché Research Centre, St Andrews) titled "Proof Theoretic Harmony in Substructural Logics".

Graham Priest (CUNY, Arché) gives a talk at the Workshop on Meaning: Models and Proofs (11-12 Oct, 2013, co-organized by the MCMP and the Arché Research Centre, St Andrews) titled "Models of Paraconsistent Set Theory".

Bjørn Jespersen (TU Ostrava) gives a talk at the MCMP Colloquium (24 October, 2013) titled "Qualifying quantifying-in". Abstract: If you know that Munich is a city, does it follow that there is an individual x and a property f such that you know that x is an f? Similarly, if you find the millionth digit of the decimal expansion of π, does it follow that there is a number y such that you find y? It does, provided the rule of existential generalization extends to so-called non-extensional contexts like those involving attitudes and modalities. I argue that EG must apply to all contexts, since the rule essentially serves to make explicit ontological commitments already implicit in the premise. Nor do non-extensional contexts cripple the rule of substitution of identicals. The law is universally valid, but its substituends must be chosen more carefully. This talk presents an extensional logic of hyperintensions that validates quantifying into hyperintensional contexts and quantifying over hyperintensions and intensions (functions from possible worlds), though not always also over extensions, due to non-factive attitudes. The talk also explains how to obtain universal transparency, i.e. a context-invariant theory of meaning and reference, by universalizing Frege’s semantics for oblique contexts. The background theory is Transparent Intensional Logic, formally a hyperintensional, partial, typed λ-calculus. TIL conceptualizes hyperintensions as structured procedures detailing how to produce an extension or intension, or even another hyperintension. My focus will be on hyperintensional attitudes, i.e. those whose complements are individuated finer than up to logical equivalence. The talk summarizes the latest results on the details of the logic of quantifying-in.

Catarina Dutilh Novaes (Groningen) gives a talk at the MCMP workshop "Carnap on Logic" (3-6 July, 2013) titled "Two conceptions of formalization: Carnapian explication, and formalisms as cognitive tools".

Sebastian Lutz (MCMP/LMU) gives a talk at the MCMP workshop "Carnap on Logic" (3-6 July, 2013) titled "On Carnap on Empirical Significance".

Peter Olen (South Florida) gives a talk at the MCMP workshop "Carnap on Logic" (3-6 July, 2013) titled "Chasing Ghosts: Understanding Carnap's pure Semantics".