The Logic and Metaphysics Workshop will meet on October 3rd from 4:15-6:15 (NY time) in-person at the Graduate Center (Room 7314) for a talk by Yale Weiss (CUNY).

Title: The best of all possible Leibnizian completeness theorems

Abstract: Leibniz developed several arithmetical interpretations of the assertoric syllogistic in a series of papers from April 1679. In this talk, I present his most mature arithmetical semantics. I show that the assertoric syllogistic can be characterized exactly not only in the full divisibility lattice, as Leibniz implicitly suggests, but in a certain four-element sublattice thereof. This refinement is also shown to be optimal in the sense that the assertoric syllogistic is not complete with respect to any smaller sublattice using Leibniz’s truth conditions.

The Logic and Metaphysics Workshop will meet on September 26th from 4:15-6:15 (NY time) via Zoom for a talk by Louise Dupuis (Paris Dauphine) and Matteo Michelini (Eindhoven).

Title: MySide bias in scientific debates

Abstract: Recent research in cognitive science supports the idea that scientific reasoning is influenced by myside resp. confirmation bias — a tendency to prioritize the search and generation of arguments that support one’s views, rather than arguments that would undermine it and, consequently, to apply more critical scrutiny to opposing than to one’s own stances (Mercier, 2017, Mercier, 2014). Even though myside bias may pull scientists away from the truth, its effects could be mitigated by certain socio-epistemic mechanisms. Moreover, if kept under control — so the argument goes — myside bias may have a positive impact on inquiry by generating an efficient division of cognitive labour. While this view stands in sharp contrast to the common take on confirmation bias as epistemically pernicious, it coheres with recent arguments from the philosophy of science that confirmation bias can be beneficial for group inquiry (Smart, 2018, Peters, 2020). This raises the question under which conditions (if any) myside bias plays such a positive role. In this paper we investigate this question by means of an argumentative agent-based model. Our results suggest that the myside bias may have an ambivalent effect on scientific debates. On the one hand, biased scientists tend to explore the given topic to a greater extent, which may facilitate a more thorough inquiry. On the other hand, they are also less likely to change their mind, which can be especially damaging in case they have reached a consensus on a wrong point of view.

Note: This is joint work with Dunja Šešelja, Juliette Rouchier, Gabriella Pigozzi, Annemarie Borg, and Christian Straßer.

The Logic and Metaphysics Workshop will meet on September 19th from 4:15-6:15 (NY time) in-person at the Graduate Center (Room 7314) for a talk by Bokai Yao (Notre Dame).

Title: Reflective Mereology

Abstract: I explore a new theory of mereology based on a mereological reflection principle. Reflective mereology has natural fusion principles but also refutes certain principles of classical mereology such as Universal Fusion and Fusion Uniqueness. Moreover, reflective mereology avoids Uzquiano’s cardinality problem–the problem that classical mereology tends to clash with set theory when they both quantify over everything. In particular, assuming large cardinals, I construct a natural model of reflective mereology and second-order ZFCU with Limitation of Size. In the model, classical mereology holds when the quantifiers are restricted to the urelements.

The Logic and Metaphysics Workshop will meet on September 12th from 4:15-6:15 (NY time) via Zoom for a talk by Yasuo Deguchi (Kyoto).

Title: Logic of Presence

Abstract: This talk will propose a new modality within the framework of possible worlds, i.e., presence or present world. Presence is defined in terms of mutual or two-ways intentionality: An object X is present to an intentional agent A in the actual world iff A has active and passive intentionalities toward X, where active intentionality means that A has intentionality to X (e.g., A loves X), and passive intentionality means that A has self-awareness/consciousness as being an object of X’s intentionality (e.g., X loves A). Some actual agents such as your partner is actual and present entity for you, while other actual objects such as minute physical events in an unknown faraway galaxy are actual but not present entities for you. Some counterfactual agents such as those in a digital virtual reality can be counterfactual but present agents for you, while some other counterfactual entities are simply counterfactual and non-present for you. This talk claims that this present approach to virtual reality is better than Chalmers’ virtual realism and Ryan’s recentering approach. This talk also outlines the logic of presence that is an extension of Priest-Berto’s logic of intentionality, being based on possible worlds semantics.