LanCog Workshop on Group Epistemology

Date: February 21, 2020

Venue: Faculdade de Letras da Universidade da Lisboa, Mattos Romão room

The LanCog group at the Centro de Filosofia, University of Lisbon, is glad to announce the upcoming Workshop on Group Epistemology, which will take place at the University of Lisbon the 21th of February 2020. We will have the pleasure to have Jennifer Lackey (Northwestern University) as a keynote speaker.



10.00 – 10.10: Greetings

10.10 – 10.50: Kenneth Boyd – Deliberation and Polarization in Anonymous and Pseudonymous Groups

Abstract: Here I will take group polarization to refer to a number of related phenomena in which members of groups becoming more extreme in their beliefs, in one way or another, after deliberation. Although different types of polarization have been discussed in different way, there are two general factors that are taken to drive polarization effects: social factors and informational factors. The former are nonrational or irrational factors that impact a member’s belief formation and updating insofar as one engages in social comparison and motivated cognition, while the latter may involve a rational (or at least not irrational) response to the quantity and order of information and arguments that one receives.

10.50 – 11.00: Break

11.00 – 11.40: Francisca Silva – Group Belief: A Lesson from Compromise

Abstract: According to non-summativist views of group belief, there are cases in which groups are said to believe a proposition, even though none of its members hold that belief. A branch of such views states that for a group to believe a given proposition is for its members (or a subset of operative members) to jointly accept it as true, with some added restrictions depending on the particular view being held. In opposition to joint acceptance accounts (JAA) of group belief, Lackey argues that group belief must follow similar constraints as beliefs on an individual level – which are not encompassed by JAA – namely: that they must not be more voluntarily acquired (to a large degree) than those at the individual level; and that they must have a mind-to-world fit. Lackey eventually reaches the conclusion that there must be, then, belief at the individual members’ level in order for there to be group belief. In arguing for this conclusion Lackey presents several cases of what JAA takes to be instances of group belief, and why these cases are not actually cases of group belief, given these constraints. One of the cases presented is a case of compromise. In disagreement with Lackey, I wish, by ways of an analysis of what is involved in instances of compromise, to show that there may be cases of this latter phenomenon in which both of Lackey’s proposed constraints on group belief are met, and yet the group has a belief that none of its members hold.

11.40 – 11.50: Break

11.50 – 12.30: Neri Marsili – Group assertions and lies

Abstract: What is it for a group to make an assertion? And under which conditions would it be appropriate to call a group statement a lie? In two recent papers, Jennifer Lackey (2017, 2018) offers a response to both questions:
(GL) A group, G, lies to B if and only if (1) G states that p to B, (2) G believes that p is false, and (3) G intends to be deceptive to B with respect to whether p in stating that p
With an improved account of group assertion in place, I will proceed to consider GL. I will argue that none of the three conditions in GL are necessary for lying: a group can lie by performing speech acts other than assertion (vs 1); with no intent to be deceitful (vs 3, cf. Fallis 2015); even if it does not outright believe that the proposition is false (vs 2). Against GL, I will argue that group lying requires that a group says that p, thereby becoming committed to the truth of a proposition that the group believes more likely to be false than true.

12.30 – 14.00: Lunch Break

14.00 – 14.40: Gregor Gaszczyk – Implicit group lies

Abstract: Groups lie. Naked Juice, one of PepsiCo companies, advertised their juices as “100% Juice” and “All Natural”. This was proven wrong. Particularly, certain ingredients in their juices were produced synthetically. Because Naked Juice knew that from the very beginning, they were lying. Standardly one lies by making a statement, for instance, “Our juices are ALL NATURAL”. But we can lie not only by making straightforward assertions but also in various other ways. I restrict to lies made by implicit content, particularly to presuppositions. They deserve special attention because, among others, Lackey’s (2018a) proposal of group lies does not capture presuppositional content.

14.40 – 14.50: Break

14.50 – 15.30: Domingos Faria – Group Testimony: defending a reductionist view

Abstract: Our aim in this talk is to defend the reductionist (or deflationist) view on group testimony from the attacks of divergence arguments. We will begin by presenting how divergence arguments can challenge the reductionist view. However, we will argue that these arguments are not decisive to rule out the reductionist view; for, these arguments have false premises, assuming dubious epistemic principles that testimony cannot generate knowledge and understanding. The final part of this talk will be devoted to presenting the advantages of the reductionist approach to explaining the phenomenon of group testimony.

15.30 – 16.00: Break

16.00 – 18.00: Jennifer Lackey – The Epistemology of Groups

Abstract: Groups are often said to believe, know, and do things. For instance, we talk about the Catholic Church believing that the Pope is infallible, the U.S. government knowing that greenhouse gases emitted by human activities are the primary driver of climate change, and Iran firing two missiles at a Ukranian passenger plane that crashed in Tehran. But how should we understand a group’s believing, knowing, or doing something? Two answers are generally given to this question. According to summativism, a group’s states or actions are understood simply in terms of the states or actions of individual members. In contrast, non-summativism holds that a group’s states or actions are over and above, or otherwise distinct from, those of its members. While I argue that neither view is, strictly speaking, correct, I also show that epistemic states and actions come apart in how much they depend on group members. In particular, there is a far tighter connection between what a group believes or knows and what its individual members believe or know than there is between what a group does and what its members do. This has important implications for our attributions of moral and legal responsibility to groups, such as corporations and institutions.



Attendance is free, but registration is required. Please, register by sending an email to <> no later than February 14. All welcome.



Domingos Faria and Michel Croce