Group Beliefs

Studies on the Nature and Logic of Collective Doxastic Attitudes

Research output: ThesisDoctoral ThesisCollection of Articles

Abstract

The present doctoral dissertation studies the nature and logic of collective
doxastic attitudes, or what is referred to in ordinary language as "group
beliefs". Beliefs and other intentional attitudes are attributed to groups and
collections of people, and such attributions are used to explain and predict
the actions of groups. The dissertation develops an understanding of group
beliefs as voluntarily adopted views or acceptances rather than as ordinary
beliefs. Such an understanding can provide new answers to questions concerning
collective knowledge and justification of group beliefs, and it allows
developing modal logics with collective doxastic and epistemic notions.
The dissertation consists of six articles. The first three are philosophical
studies concerned with the nature of collective doxastic attitudes. The last
three articles, which are written jointly with Sara Negri, are logical studies
concerned with the logic of collective doxastic attitudes. Here is a short
review of the articles.

Among the former, the first one concerns the question whether group
beliefs are beliefs or acceptances. The second one discusses the possibility
of group knowledge, and the third one justification of group beliefs. Among
the latter, the first concerns one prerequisite for developing a proof theory
for modal logics in general, including doxastic and epistemic logics. The
last two present sequent calculus systems for logics that express properties
of two types of collective attitudes, distributed knowledge and group beliefs,
respectively.

In 'Group beliefs and the distinction between belief and acceptance', I
study the existing literature on group beliefs. There are two notions of group
beliefs: summative group beliefs, which are reducible to individual beliefs,
and non-summative, which are not reducible to individual beliefs but are
based on what the group members decide to take as the group's view. I use
the distinction between belief and acceptance to argue that non-summative
group beliefs are acceptances rather than ordinary beliefs. In the article, I
attempt to clarify the discussion by making the distinction between belief and
acceptance more precise than it had previously been made. The suggestion
is to define acceptances as voluntary doxastic states, in contrast to beliefs,
which are usually understood to be involuntary.

In `On the possibility of group knowledge without belief', I consider the
possibility of attributing knowledge to groups in spite of the conclusion of
the previous article that group beliefs might not be beliefs. This requires
a modification of standard epistemological theories that see knowledge as
belief satisfying certain conditions. The modification is plausible if we see
the distinction between belief and acceptance as a refinement of our ordinary language concept of belief. I also argue that the voluntariness of acceptance
suggests that its justification should be taken to require reasons for the accepted
view, whereas this may not be required for justification of belief.

In `On dialectical justification of group beliefs', I pursue the idea of the
previous article that voluntariness of group belief, and of acceptance more
generally, has consequences concerning the epistemic justification of such
doxastic states. I argue that it is plausible to require reasons for voluntary
acceptances whereas the epistemic assessment of involuntary beliefs may be
understood purely externalistically. I concentrate on dialectical theories of
justification and argue that the justification of group beliefs could be understood
dialectically.

In `Does the deduction theorem fail for modal logic?', we study the recent
claims according to which the deduction theorem fails for modal logics. The
deduction theorem states a property that is necessary for developing sequent
calculus systems for modal logics, including doxastic and epistemic logics.
We show that the deduction theorem holds when a correct formulation of
the inference rules and an appropriate understanding of logical consequence
are given.

In `Proof theory for distributed knowledge', we develop a cut-free Gentzen-type
sequent calculus for a multi-agent epistemic logic that is extended by
an operator for distributed knowledge. Something is distributed knowledge
within a group if and only if it is entailed by the totality of the knowledge
of the individuals belonging to the group. By interpreting the knowledge
modalities as belief (or acceptance) operators, the system can be used for reasoning about certain summative collective doxastic attitudes, such as shared
and distributed beliefs.

In `Reasoning about collectively accepted group beliefs', we extend the
methods of the previous paper to logics that concern non-summative group
beliefs. The proof-theoretical methods apply to the basic logic and to extensions
concerned with the aggregation of individual acceptances into a group
view. It turns out that care must be taken in defining the modalities in a
way that does not lead to inconsistent group beliefs in situations such as the
discursive dilemma in which there is a majority both for a conclusion and
premisses entailing the negation of the conclusion.
Original languageEnglish
Print ISBNs978-952-10-6731-0
Publication statusPublished - Dec 2010
MoE publication typeG5 Doctoral dissertation (article)

Fields of Science

  • 611 Philosophy

Cite this

@phdthesis{ce256a0f671342d1ab9c99bed5ada284,
title = "Group Beliefs: Studies on the Nature and Logic of Collective Doxastic Attitudes",
abstract = "The present doctoral dissertation studies the nature and logic of collectivedoxastic attitudes, or what is referred to in ordinary language as {"}groupbeliefs{"}. Beliefs and other intentional attitudes are attributed to groups andcollections of people, and such attributions are used to explain and predictthe actions of groups. The dissertation develops an understanding of groupbeliefs as voluntarily adopted views or acceptances rather than as ordinarybeliefs. Such an understanding can provide new answers to questions concerningcollective knowledge and justification of group beliefs, and it allowsdeveloping modal logics with collective doxastic and epistemic notions.The dissertation consists of six articles. The first three are philosophicalstudies concerned with the nature of collective doxastic attitudes. The lastthree articles, which are written jointly with Sara Negri, are logical studiesconcerned with the logic of collective doxastic attitudes. Here is a shortreview of the articles.Among the former, the first one concerns the question whether groupbeliefs are beliefs or acceptances. The second one discusses the possibilityof group knowledge, and the third one justification of group beliefs. Amongthe latter, the first concerns one prerequisite for developing a proof theoryfor modal logics in general, including doxastic and epistemic logics. Thelast two present sequent calculus systems for logics that express propertiesof two types of collective attitudes, distributed knowledge and group beliefs,respectively.In 'Group beliefs and the distinction between belief and acceptance', Istudy the existing literature on group beliefs. There are two notions of groupbeliefs: summative group beliefs, which are reducible to individual beliefs,and non-summative, which are not reducible to individual beliefs but arebased on what the group members decide to take as the group's view. I usethe distinction between belief and acceptance to argue that non-summativegroup beliefs are acceptances rather than ordinary beliefs. In the article, Iattempt to clarify the discussion by making the distinction between belief andacceptance more precise than it had previously been made. The suggestionis to define acceptances as voluntary doxastic states, in contrast to beliefs,which are usually understood to be involuntary.In `On the possibility of group knowledge without belief', I consider thepossibility of attributing knowledge to groups in spite of the conclusion ofthe previous article that group beliefs might not be beliefs. This requiresa modification of standard epistemological theories that see knowledge asbelief satisfying certain conditions. The modification is plausible if we seethe distinction between belief and acceptance as a refinement of our ordinary language concept of belief. I also argue that the voluntariness of acceptancesuggests that its justification should be taken to require reasons for the acceptedview, whereas this may not be required for justification of belief.In `On dialectical justification of group beliefs', I pursue the idea of theprevious article that voluntariness of group belief, and of acceptance moregenerally, has consequences concerning the epistemic justification of suchdoxastic states. I argue that it is plausible to require reasons for voluntaryacceptances whereas the epistemic assessment of involuntary beliefs may beunderstood purely externalistically. I concentrate on dialectical theories ofjustification and argue that the justification of group beliefs could be understooddialectically.In `Does the deduction theorem fail for modal logic?', we study the recentclaims according to which the deduction theorem fails for modal logics. Thededuction theorem states a property that is necessary for developing sequentcalculus systems for modal logics, including doxastic and epistemic logics.We show that the deduction theorem holds when a correct formulation ofthe inference rules and an appropriate understanding of logical consequenceare given.In `Proof theory for distributed knowledge', we develop a cut-free Gentzen-typesequent calculus for a multi-agent epistemic logic that is extended byan operator for distributed knowledge. Something is distributed knowledgewithin a group if and only if it is entailed by the totality of the knowledgeof the individuals belonging to the group. By interpreting the knowledgemodalities as belief (or acceptance) operators, the system can be used for reasoning about certain summative collective doxastic attitudes, such as sharedand distributed beliefs.In `Reasoning about collectively accepted group beliefs', we extend themethods of the previous paper to logics that concern non-summative groupbeliefs. The proof-theoretical methods apply to the basic logic and to extensionsconcerned with the aggregation of individual acceptances into a groupview. It turns out that care must be taken in defining the modalities in away that does not lead to inconsistent group beliefs in situations such as thediscursive dilemma in which there is a majority both for a conclusion andpremisses entailing the negation of the conclusion.",
keywords = "611 Philosophy, yhteiskuntatieteen filosofia, tietoteoria, logiikka, modaalilogiikka, ryhm{\"a}uskomukset, todistusteoria",
author = "Raul Hakli",
year = "2010",
month = "12",
language = "English",
isbn = "978-952-10-6731-0",
series = "Philosophical Studies from the University of Helsinki",
number = "32",

}

Group Beliefs : Studies on the Nature and Logic of Collective Doxastic Attitudes. / Hakli, Raul.

2010.

Research output: ThesisDoctoral ThesisCollection of Articles

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T1 - Group Beliefs

T2 - Studies on the Nature and Logic of Collective Doxastic Attitudes

AU - Hakli, Raul

PY - 2010/12

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N2 - The present doctoral dissertation studies the nature and logic of collectivedoxastic attitudes, or what is referred to in ordinary language as "groupbeliefs". Beliefs and other intentional attitudes are attributed to groups andcollections of people, and such attributions are used to explain and predictthe actions of groups. The dissertation develops an understanding of groupbeliefs as voluntarily adopted views or acceptances rather than as ordinarybeliefs. Such an understanding can provide new answers to questions concerningcollective knowledge and justification of group beliefs, and it allowsdeveloping modal logics with collective doxastic and epistemic notions.The dissertation consists of six articles. The first three are philosophicalstudies concerned with the nature of collective doxastic attitudes. The lastthree articles, which are written jointly with Sara Negri, are logical studiesconcerned with the logic of collective doxastic attitudes. Here is a shortreview of the articles.Among the former, the first one concerns the question whether groupbeliefs are beliefs or acceptances. The second one discusses the possibilityof group knowledge, and the third one justification of group beliefs. Amongthe latter, the first concerns one prerequisite for developing a proof theoryfor modal logics in general, including doxastic and epistemic logics. Thelast two present sequent calculus systems for logics that express propertiesof two types of collective attitudes, distributed knowledge and group beliefs,respectively.In 'Group beliefs and the distinction between belief and acceptance', Istudy the existing literature on group beliefs. There are two notions of groupbeliefs: summative group beliefs, which are reducible to individual beliefs,and non-summative, which are not reducible to individual beliefs but arebased on what the group members decide to take as the group's view. I usethe distinction between belief and acceptance to argue that non-summativegroup beliefs are acceptances rather than ordinary beliefs. In the article, Iattempt to clarify the discussion by making the distinction between belief andacceptance more precise than it had previously been made. The suggestionis to define acceptances as voluntary doxastic states, in contrast to beliefs,which are usually understood to be involuntary.In `On the possibility of group knowledge without belief', I consider thepossibility of attributing knowledge to groups in spite of the conclusion ofthe previous article that group beliefs might not be beliefs. This requiresa modification of standard epistemological theories that see knowledge asbelief satisfying certain conditions. The modification is plausible if we seethe distinction between belief and acceptance as a refinement of our ordinary language concept of belief. I also argue that the voluntariness of acceptancesuggests that its justification should be taken to require reasons for the acceptedview, whereas this may not be required for justification of belief.In `On dialectical justification of group beliefs', I pursue the idea of theprevious article that voluntariness of group belief, and of acceptance moregenerally, has consequences concerning the epistemic justification of suchdoxastic states. I argue that it is plausible to require reasons for voluntaryacceptances whereas the epistemic assessment of involuntary beliefs may beunderstood purely externalistically. I concentrate on dialectical theories ofjustification and argue that the justification of group beliefs could be understooddialectically.In `Does the deduction theorem fail for modal logic?', we study the recentclaims according to which the deduction theorem fails for modal logics. Thededuction theorem states a property that is necessary for developing sequentcalculus systems for modal logics, including doxastic and epistemic logics.We show that the deduction theorem holds when a correct formulation ofthe inference rules and an appropriate understanding of logical consequenceare given.In `Proof theory for distributed knowledge', we develop a cut-free Gentzen-typesequent calculus for a multi-agent epistemic logic that is extended byan operator for distributed knowledge. Something is distributed knowledgewithin a group if and only if it is entailed by the totality of the knowledgeof the individuals belonging to the group. By interpreting the knowledgemodalities as belief (or acceptance) operators, the system can be used for reasoning about certain summative collective doxastic attitudes, such as sharedand distributed beliefs.In `Reasoning about collectively accepted group beliefs', we extend themethods of the previous paper to logics that concern non-summative groupbeliefs. The proof-theoretical methods apply to the basic logic and to extensionsconcerned with the aggregation of individual acceptances into a groupview. It turns out that care must be taken in defining the modalities in away that does not lead to inconsistent group beliefs in situations such as thediscursive dilemma in which there is a majority both for a conclusion andpremisses entailing the negation of the conclusion.

AB - The present doctoral dissertation studies the nature and logic of collectivedoxastic attitudes, or what is referred to in ordinary language as "groupbeliefs". Beliefs and other intentional attitudes are attributed to groups andcollections of people, and such attributions are used to explain and predictthe actions of groups. The dissertation develops an understanding of groupbeliefs as voluntarily adopted views or acceptances rather than as ordinarybeliefs. Such an understanding can provide new answers to questions concerningcollective knowledge and justification of group beliefs, and it allowsdeveloping modal logics with collective doxastic and epistemic notions.The dissertation consists of six articles. The first three are philosophicalstudies concerned with the nature of collective doxastic attitudes. The lastthree articles, which are written jointly with Sara Negri, are logical studiesconcerned with the logic of collective doxastic attitudes. Here is a shortreview of the articles.Among the former, the first one concerns the question whether groupbeliefs are beliefs or acceptances. The second one discusses the possibilityof group knowledge, and the third one justification of group beliefs. Amongthe latter, the first concerns one prerequisite for developing a proof theoryfor modal logics in general, including doxastic and epistemic logics. Thelast two present sequent calculus systems for logics that express propertiesof two types of collective attitudes, distributed knowledge and group beliefs,respectively.In 'Group beliefs and the distinction between belief and acceptance', Istudy the existing literature on group beliefs. There are two notions of groupbeliefs: summative group beliefs, which are reducible to individual beliefs,and non-summative, which are not reducible to individual beliefs but arebased on what the group members decide to take as the group's view. I usethe distinction between belief and acceptance to argue that non-summativegroup beliefs are acceptances rather than ordinary beliefs. In the article, Iattempt to clarify the discussion by making the distinction between belief andacceptance more precise than it had previously been made. The suggestionis to define acceptances as voluntary doxastic states, in contrast to beliefs,which are usually understood to be involuntary.In `On the possibility of group knowledge without belief', I consider thepossibility of attributing knowledge to groups in spite of the conclusion ofthe previous article that group beliefs might not be beliefs. This requiresa modification of standard epistemological theories that see knowledge asbelief satisfying certain conditions. The modification is plausible if we seethe distinction between belief and acceptance as a refinement of our ordinary language concept of belief. I also argue that the voluntariness of acceptancesuggests that its justification should be taken to require reasons for the acceptedview, whereas this may not be required for justification of belief.In `On dialectical justification of group beliefs', I pursue the idea of theprevious article that voluntariness of group belief, and of acceptance moregenerally, has consequences concerning the epistemic justification of suchdoxastic states. I argue that it is plausible to require reasons for voluntaryacceptances whereas the epistemic assessment of involuntary beliefs may beunderstood purely externalistically. I concentrate on dialectical theories ofjustification and argue that the justification of group beliefs could be understooddialectically.In `Does the deduction theorem fail for modal logic?', we study the recentclaims according to which the deduction theorem fails for modal logics. Thededuction theorem states a property that is necessary for developing sequentcalculus systems for modal logics, including doxastic and epistemic logics.We show that the deduction theorem holds when a correct formulation ofthe inference rules and an appropriate understanding of logical consequenceare given.In `Proof theory for distributed knowledge', we develop a cut-free Gentzen-typesequent calculus for a multi-agent epistemic logic that is extended byan operator for distributed knowledge. Something is distributed knowledgewithin a group if and only if it is entailed by the totality of the knowledgeof the individuals belonging to the group. By interpreting the knowledgemodalities as belief (or acceptance) operators, the system can be used for reasoning about certain summative collective doxastic attitudes, such as sharedand distributed beliefs.In `Reasoning about collectively accepted group beliefs', we extend themethods of the previous paper to logics that concern non-summative groupbeliefs. The proof-theoretical methods apply to the basic logic and to extensionsconcerned with the aggregation of individual acceptances into a groupview. It turns out that care must be taken in defining the modalities in away that does not lead to inconsistent group beliefs in situations such as thediscursive dilemma in which there is a majority both for a conclusion andpremisses entailing the negation of the conclusion.

KW - 611 Philosophy

KW - yhteiskuntatieteen filosofia

KW - tietoteoria

KW - logiikka

KW - modaalilogiikka

KW - ryhmäuskomukset

KW - todistusteoria

M3 - Doctoral Thesis

SN - 978-952-10-6731-0

T3 - Philosophical Studies from the University of Helsinki

ER -

Hakli R. Group Beliefs: Studies on the Nature and Logic of Collective Doxastic Attitudes. 2010. (Philosophical Studies from the University of Helsinki; 32).