LanCog Logic Seminar Series

Friday, March 10, 10:00—12:00 (UTC)

The University of Lisbon

Faculty of Letters, room B112.G (Library wing)

Francesca Boccuni

University San Raffaele, Milan

The Logical Ontology of Abstractionism

Neologicism aims at founding arithmetic on full second-order logic and Hume’s Principle, which states that the number of the Fs is identical with the number of the Gs if, and only if, there are as many Fs as Gs, and vice versa. Nevertheless, Neologicism faces the problem of the logical ontology ([5]), according to which the underlying second-order logic is ontologically committal. In this paper, such a problem will be tackled by substituting second-order logic by Boolos’ plural logic ([2, 3]), augmented by the Plural Frege Quantifier Fmodelled on [1]. The resulting theory (PHP) interprets second-order Peano arithmetic PA2. Its ontological innocence will be evaluated. In this respect, PHP provides an alternative that solves the problem of the logical ontology pervading Neologicism.

References

[1] Antonelli, A. (2010), ‘Numerical Abstraction via the Frege Quantifier’, Notre Dame Journal of Formal Logic 51(2): 161–179.

[2] Boolos, G. (1998a), ‘To be is to be the Value of a Variable (or the Values of Some Variables)’, in [4]: 54–72.

[3] Boolos, G. (1998b), ‘Nominalist Platonism’, in [4]: 73–87.

[4] Boolos, G. (1998c), Logic, Logic, and Logic, J. Burgess & R. Jeffrey (eds.), Cambridge, MA: Harvard University Press.

[5] Hale, B. & Wright, C. (2001), The Reason’s Proper Study: Essays towards a Neo-Fregean Philosophy of Mathematics, Oxford University Press.

How to Build Things With Atoms

Claudio Calosi

University of Geneva

10 March 2023, 16:00 (Lisbon Time – WET)

Faculdade de Letras de Lisboa

Sala Mattos Romão (Departamento de Filosofia)

Abstract: Atomism is the thesis that everything is ultimately composed of atoms. Typically, this thesis is characterized by an axiom stating that everything has atomic parts. The present paper argues that the success of this standard characterization crucially depends on how the notion of sum and composition are defined. In particular, it puts forward a novel definition of mereological sum that: (i) is not equivalent to extant definitions in the literature, provided no strong decomposition principle is assumed, (ii) can be used to claim that the standard characterization of atomism fails in that having atomic parts is not sufficient to be the sum of atoms,  (iii) delivers a purely mereological distinction between structured and unstructured wholes, and (iv) is sensitive to the (alleged) hierarchical nature of composition.

Mechanistic Computation and its Problems: An Abstract Solution

Luke Kersten

LanCog, University of Lisbon

3 March 2023, 16:00 (Lisbon Time – WET)

Faculdade de Letras de Lisboa

Sala Mattos Romão (Departamento de Filosofia)

Abstract: The mechanistic account of computation (or MAC) maintains that computational implementation is best explicated within a mechanistic framework. A physical system is said to implement a computation only if it processes medium-independent vehicles in virtue of being a functional mechanism. Recently, a number of objections have been raised to MAC, including the “decomposition”, “abstraction”, “generality”, and “hierarchy” problems. These challenges threaten to undermine MAC’s status as a workable theory of implementation. The aim of this paper is to shore up MAC’s conceptual foundations by responding to each. After unpacking the four problems, I outline a recent proposal from Kuokkanen (2022a) which argues that MAC can be rescued by employing a distinction between “vertical” and “horizontal” abstraction. I argue that, while promising, Kuokkanen’s proposal comes at too high a price, requiring MAC to sacrifice its claims on “extensional adequacy”. In response, I outline what I call the “computation-as-abstracta” view. I suggest that thinking of computation as a form of abstracta not only helps to dissolve the four problems but also provides a way of retaining extensional adequacy in the process. I conclude by taking up two further problems recently articulated by Shagrir (2022) and Kuokkanen (2022b).

Epistemic Akrasia and the Nature of Mental Fragments

João C. Miranda

LanCog, University of Lisbon

24 February 2023, 16:00 (Lisbon Time – WET)

Faculdade de Letras de Lisboa

Sala Mattos Romão (Departamento de Filosofia)

Abstract: An agent S is epistemically akratic if and only if (i) S believes that p and (ii) S believes that they shouldn’t believe that p. The main debate about epistemic akrasia concerns its characterization and explanation: what is needed is an account of what mechanisms make cases of epistemic akrasia possible. Greco (2014) and Kearl (2020) have defended fragmentalist accounts of epistemic akrasia: there is not one unique belief-formation system, and the possibility of epistemic akrasia rests on the possibility of conflict between the different systems. I’ll argue that their versions fail, for their responses to pressing worries about the meta-epistemological theory that underlies them – epistemic expressivism – are unsatisfactory. I will then rescue fragmentalism by proposing a version that focuses, not on the linguistic/non-linguistic nature of the systems, but on the constraints under which beliefs are formed. Doing so will allow me to appeal to well established literature in psychology about a distinction between explicit reasoning and heuristic-based reasoning (Gigerenzer, Todd and the ABC Research Group, 1999; Kanheman, 2011). I’ll argue that, not only is there better empirical support for my version of fragmentalism, but it also avoids the problems that plagued Greco and Kearl’s account.

The Special Composition Question: An Analysis of Carmichael’s Commonsense Account

Marta Campdelacreu

University of Barcelona

17 February 2023, 16:00 (Lisbon Time – WET)

Faculdade de Letras de Lisboa

Sala Mattos Romão (Departamento de Filosofia)

Abstract: This is Peter van Inwagen’s well-known Special Composition Question: when do some things compose something? Recently, Carmichael has proposed and defended an appealing new answer which, unlike the current most popular answers, agrees with common sense regarding composition. Moreover, he claims, it helps to solve the puzzle of The Ship of Theseus and the puzzle of Dion and Theon. In this talk, I will argue that Carmichael’s proposal includes an unjustified and arbitrary distinction between the relation that common sense bears to objects and the relation that it bears to events. Moreover, I will also argue that, against what he claims, his proposal does not help to solve the puzzles mentioned before.

Faculty of Arts and Humanities. Centre of Philosophy of the University of Lisbon. University of Lisbon (Lisbon, Portugal)

We invite submissions to the PLEXUS inaugural conference, which will take place on May 24-26 at the Centre of Philosophy of the University of Lisbon, Portugal. Submissions can be on any topic related to substructural logics and should be suitable for 45 minutes presentations.

Please send an anonymised abstract of at most 500 words alongside a separate title page, containing the name of the author and the title of the presentation to bdicher@edu.ulisboa.pt before 15 February 2023. Please include the acronym ‘PLEXUS’ in the email’s subject field. Notifications of acceptance will be sent before 15 February 2023.

Submissions from early-stage scholars and postgraduate students, as well as from members of groups currently underrepresented in academia, are strongly encouraged. Some financial support to cover travel and accommodation costs will be available for postgraduate students. Should you wish to be considered for financial support, please state so on the ‘title page’.

Date: November 17 and 18, 2022.

The Cogito research group (University of Glasgow) and the LanCog research group (University of Lisbon) are glad to announce the upcoming Epistemology Workshop, which will take place on November 17 and 18, 2022, at Faculty of Letters, University of Lisbon.

Programme November 17 (Thursday) 2.00-3.45 – Mona Simion (University of Glasgow) 4.00-5.45 – Matt McGrath (Washington University St Louis) November 18 (Friday) 9.00-10.45 – Michel Croce & Matt Jope (University of Genoa & University of Edinburgh) 11.00-12.45 – Claire Fields (University of Stirling) 12.45-2.00 Lunch 2.00-3.45 – Domingos Faria (University of Porto) 4.00-5.45 – Chris Kelp (University of Glasgow) Location Faculty of Letters, University of Lisbon, B112B Room (Library building)   Organizers Mona Simion and Domingos Faria

Inferential Constraint and If φ ought φ Problem

Una Stojnić

Princeton University

23 September 2022, 16:00 (Lisbon Time – WET)

Faculdade de Letras de Lisboa

Sala Mattos Romão (Departamento de Filosofia)

Abstract: The standard semantics for modality, together with the influential restrictor analysis of conditionals (Kratzer 1986; 2012) renders conditional ‘ought’ claims like (1) trivially true:

1. If John’s stealing, he ought to be stealing.

While this might seem like a problem specifically for the restrictor analysis, the issue is far more general. For any account must predict that modals in the consequent sometimes receive obligatorily unrestricted interpretation, as in (1), but sometimes appear restricted, as in (2):

2. If John’s speeding, he ought to pay the fine.

And the problem runs deeper, for there are non-conditional variants of the data. Thus, the solution cannot lie in adopting a particular analysis of conditionals, nor a specific account of the interaction between conditionals and modals. Indeed, with minimal assumptions, the standard account of modality will render a massive number of claims about what one ought to, must, or may, do trivially true. Worse, the problem extends to a wide range of non-deontic modalities, including metaphysical modality. But the disaster has a remedy. I argue that the source of the problem lies in the standard account’s failure to capture an inferential evidence constraint encoded in the meaning of a wide range of modal constructions. I offer an account that captures this constraint, and show it provides a general and independently motivated solution to the problem.