Cognitive Synonymy: a Dead Parrot?

Francesco Berto (University of St Andrews)

(joint work with Levin Hornischer, Ludwig Maximilian University of Munich)


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

Faculdade de Letras de Lisboa

Sala Mattos Romão (Departamento de Filosofia)


Abstract: Sentences φ and ψ are cognitive synonyms for one when they play the same role in one’s cognitive life: what one understands given either, one does, given the other; what one concludes (deductively, abductively, inductively, etc.) supposing either, one does, supposing the other; one would revise one’s beliefs in the same way after learning either; etc. The notion is pervasive in linguistic and philosophical semantics, cogpsi, and AI – but elusive: it’s bound to be hyperintensional, but excessive fine-graining, e.g., by indiscriminate use of ‘open’ impossible worlds, would trivialize it and there are independent reasons for some coarse-graining. It should be sensitive to subject matters and conceptual limitations, but this stands in the way of a natural algebra: even non-distributive or non-modular lattices won’t do. Besides, a cognitively adequate individuation of content may be intransitive due to ‘dead parrot’ series (yeah the Monty Python are involved!): sequences φ1, …, φn where adjacent φi,φj are cognitive synonyms for one while φ1 and φn are not. But finding an intransitive account is hard: Fregean equipollence won’t do and an impossibility result by Leitgeb shows that it wouldn’t satisfy a minimal compositionality principle. Sed contra, there are reasons for transitivity, too (from substitutivity salva veritate, non-mononotonicity, and uniformity principles). In spite of this mess, we come up with a formal semantics capturing this whole jumble of desiderata, thereby giving evidence that the notion is coherent. We then re-assess dead parrot cases in its light.

A Problem for Greco’s Anti-Reductionism

Nuno Venturinha (IFILNOVA, New University of Lisbon)


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

Faculdade de Letras de Lisboa

Sala Mattos Romão (Departamento de Filosofia)


Abstract: In his most recent work, culminating in The Transmission of Knowledge, John Greco adopts a new epistemological perspective, arguing that knowledge transmission cannot be viewed as reducible to knowledge generation. The purpose of Greco’s “anti-reductionist theory of knowledge transmission” is not simply to specify that there are two irreducible “ways of coming to know”. Rather, Greco sets out to formulate a unified virtue-theoretic account of generative and transmissive knowledge. But while his framework convincingly addresses the individualism objection often levelled against virtue epistemology, it problematically incorporates a third kind of knowledge, that of “common knowledge” or “hinge knowledge”, which shares the property of irreducibility with generated and transmitted knowledge. In this paper, I will discuss the all-pervasive and inescapable nature of hinge commitments, raising difficulties for the anti-reductionism that characterizes Greco’s “unified epistemology of generated, transmitted, and hinge knowledge”. If the latter is to be understood in terms of procedural knowledge or “tacit knowledge that is constitutive of cognitive virtue”, as Greco suggests, then it seems hard to escape the conclusion that both generated and transmitted knowledge are ultimately reducible to hinge knowledge.

Graded Properties

Claudio Calosi (University of Geneva) & Robert Michels (LanCog, University of Lisbon)


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

Faculdade de Letras de Lisboa

Sala Mattos Romão (Departamento de Filosofia)


Abstract: The idea that properties can be had partly or to a certain degree is controversial, but also has a considerable pedigree among philosophers and scientists who either embrace or at least hint at an ontology of graded properties. In this paper, we first aim to show that metaphysical sense can be made of this idea by proposing a partial taxonomy of metaphysical accounts of graded properties, focusing on three particular approaches: one which explicates having a property to a degree in terms of having a property with an in-built degree, another based on the idea that instantiation admits of degrees, and a third which derives the degree to which properties are had from the aspects of multi-dimensional properties. Our second aim is to demonstrate that the choice between these account can make a substantial metaphysical difference by way of a number of case studies.

The Centre of Philosophy of the University of Lisbon invites to submit abstracts for contributed talks to be presented at the international conference Open Topics in Philosophy of Physics. The conference will take place from Monday 12 to Wednesday 14 of June 2023 and will discuss a variety of open topics in the foundations, philosophy and metaphysics of physics, with a special focus on quantum mechanics, philosophy of space-time and statistical mechanics.


Invited speakers: Craig Callender (San Diego), Elena Castellani (Florence), Mario Hubert (American University of Cairo), Emilia Margoni (Florence & Geneva), Andrea Oldofredi (Lisbon), Patricia Palacios (Salzburg), Bryan Roberts (LSE), Giovanni Valente (Polytechnic University of Milan), Alastair Wilson (Birmingham), David Yates (Lisbon).


Call for abstracts

Submissions of proposals for contributed talks should address a relevant topic within the foundations, philosophy or metaphysics of physics, broadly conceived. Examples of topics which are of interest for the conference are (but not limited to) the following:

  • Foundations and philosophy of quantum mechanics
  • Metaphysics of quantum mechanics
  • Interpretation and open problems in quantum field theory
  • Thermodynamics and statistical mechanics
  • Time’s arrow and the nature of time in physics
  • Philosophy of space-time (general relativity, quantum gravity)

Submissions from PhD students, early postdocs and young researchers are especially welcome. Each contributed talk will be allocated a slot of 30 minutes, including discussion.


Submission procedure

Abstracts of maximum 600 words (including bibliography) should be submitted through the following submission link

  • The deadline for submitting the abstracts is April 10th, 2023.
  • The notification of acceptance for the selected contributed talks will be communicated by April 30th, 2023.


For any information or further queries about the conference, please contact the organizer (Davide Romano) at the following email address:

Updated information about the conference can be found at the following conference website.
PhilEvents webpage

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.



[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 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’.