Hans Rott - Academia.edu (original) (raw)
Papers by Hans Rott
Journal of Logic and Computation, Jul 12, 2018
According to the Lockean thesis, a proposition is believed just in case it is highly probable. Wh... more According to the Lockean thesis, a proposition is believed just in case it is highly probable. While this thesis enjoys strong intuitive support, it is known to conflict with seemingly plausible logical constraints on our beliefs. One way out of this conflict is to make probability 1 a requirement for belief, but most have rejected this option for entailing what they see as an untenable skepticism. Recently, two new solutions to the conflict have been proposed that are alleged to be non-skeptical. We compare these proposals with each other and with the Lockean thesis, in particular with regard to the question of how much we gain by adopting any one of them instead of the probability 1 requirement, that is, of how likely it is that one believes more than the things one is fully certain of.
Journal of Logic and Computation, 2018
According to the Lockean thesis, a proposition is believed just in case it is highly probable. Wh... more According to the Lockean thesis, a proposition is believed just in case it is highly probable. While this thesis enjoys strong intuitive support, it is known to conflict with seemingly plausible logical constraints on our beliefs. One way out of this conflict is to make probability 1 a requirement for belief, but most have rejected this option for entailing what they see as an untenable skepticism. Recently, two new solutions to the conflict have been proposed that are alleged to be non-skeptical. We compare these proposals with each other and with the Lockean thesis, in particular with regard to the question of how much we gain by adopting any one of them instead of the probability 1 requirement, that is, of how likely it is that one believes more than the things one is fully certain of.
Information processing, rational beliefs and social interaction (10w2133) August 27-August 29, 20... more Information processing, rational beliefs and social interaction (10w2133) August 27-August 29, 2010 MEALS Coffee Breaks: As per daily schedule, 2nd floor lounge, Corbett Hall (included in workshop)
Cultures. Conflict - Analysis - Dialogue, 2007
This paper argues that problems of epistemology and problems of belief change are tightly interwo... more This paper argues that problems of epistemology and problems of belief change are tightly interwoven and that a successful analysis of knowledge depends on a proper solution of the problems of belief change Following Keith Lehrer we assume that what an agent knows at a certain instant is dependent upon how he is inclined to change his beliefs in time However two of Lehrers fundamental concepts personal justication and undefeated justication turn out be problematic I argue that systematic solutions to the problems must have recourse to a welldeveloped theory of belief change While this argument tries to establish that the theory of the static concept of knowledge needs help from the theory of the dynamics of belief it is nally argued that the reverse strategy should be followed in studies of belief change where the crucial epistemological distinction between foundationalism and coherentism proves useful for the analysis of belief representation and revision Keywords Epistemology theo...
Choice or selection functions are a classical device in the semantic study of conditionals, belie... more Choice or selection functions are a classical device in the semantic study of conditionals, belief revision and nonmonotonic reasoning (see for instance Lewis 1973, Alchourr6n, G£rdenfors and Makinson 1985, Delgrande 1987). It has been pointed out repeatedly that particular properties of choice functions are needed to yield some particular properties of the desired logics (Lewis 1973, p. 58; Nute 1980, p. 22, 1994, p. 370; Delgrande 1987, p. 114; Lamarre 1991, p. 362; Schlechta 1992, p. 682, and 1996; Rott 1993 and 1994; LindstrSm 1994). What is missing, however, is a unified treatment of nonmonotonic reasoning and belief revision in the general framework of rational choice that makes use of the vast body of literature available there. There are a lot of concepts, insights and techniques in rational choice that wait to be utitized by researchers working in logic, artificial intelligence and computer science.
The contraposing conditional 'If A then C' is defined by the conjunction of A > C and ... more The contraposing conditional 'If A then C' is defined by the conjunction of A > C and ~C > ~A, where > is a conditional of the kind studied by Stalnaker, Lewis and others. This idea has recently been explored, under the name 'evidential conditional', in a sequence of papers by Crupi and Iacona and Raidl, and it has been found of independent interest by Booth and Chandler. I discuss various properties of these conditionals and compare them to the 'difference-making conditionals' studied by Rott, which are defined by the conjunction of A > C and not ~A > C. I raise some doubts about Crupi and Iacona's claim that contraposition captures the idea of evidence or support.
The purpose of this paper is to link the logical theories of nonmonotonic reasoning and belief ch... more The purpose of this paper is to link the logical theories of nonmonotonic reasoning and belief change to the general theory of rational choice that derives from micro-economic theorizing.
In this paper I present the model of ‘bounded revision’ that is based on two-dimensional revision... more In this paper I present the model of ‘bounded revision’ that is based on two-dimensional revision functions taking as arguments pairs consisting of an input sentence and a reference sentence. The key idea is similar to the model of ‘revision by comparison’ investigated by Fermé and Rott (Artificial Intelligence 157, 2004). In contrast to the latter, however, bounded revision satisfies the AGM axioms as well as the Darwiche-Pearl axioms. Two onedimensional special cases are obtained by setting one argument of the two-dimensional revision operation to certain extremal values. Bounded revision thus fills the space between conservative revision (also known as natural revision) and moderate revision (also known as lexicographic revision). I argue that two-dimensional revision operations add decisively to the expressive power of qualitative approaches that refrain from assuming numbers as measures of degrees of belief.
In this paper I compare two dierent the models of two-dimensional belief change, namely 'revi... more In this paper I compare two dierent the models of two-dimensional belief change, namely 'revision by comparison' (Ferme and Rott, Artifi- cial Intelligence 157, 2004) and 'bounded revision' (Rott, in Hommage ` Wlodek, Uppsala 2007). These revision operations are two-dimensional in the sense that they take as arguments pairs consisting of an input sentence and a reference sentence. Two-dimensional revision operations add a lot to the expressive power of traditional qualitative approaches to belief revision and refrain from assuming numbers as measures of degrees of belief.
muß müssen" sagt der Jude Nathan zum Derwisch, und dieses Wort ist in einem weiteren Umfange wahr... more muß müssen" sagt der Jude Nathan zum Derwisch, und dieses Wort ist in einem weiteren Umfange wahr, als man demselben vielleicht einräumen möchte. Der Wille ist der Geschlechtscharakter des Menschen, und die Vernunft selbst ist nur die ewige Regel desselben. Vernünftig handelt die ganze Natur; sein Prärogativ ist bloß, daß er mit Bewußtseyn und Willen vernünftig handelt. Alle andere Dinge müssen; der Mensch ist das Wesen, welches will. (NA 21, 38) Mit diesen Worten beginnt Schiller seinen Aufsatz "Über das Erhabene". Vermutlich ist diese Schrift in der ersten Hälfte der 1790er Jahre entstanden. Eine genaue Datierung ist nicht mehr möglich. Man darf aber annehmen, dass sie Schiller zur Erstveröffentlichung im dritten Band seiner Kleineren prosaischen Schriften im Mai 1801 gründlich überarbeitet hat. Einen Hinweis darauf mag man darin sehen, dass er im Monat zuvor, einem lang gehegten Wunsche Goethes folgend, eine Bühnenbearbeitung von Lessings Nathan für die Aufführung im Weimarer Theater vorbereitet hatte. 1 Jedenfalls ist "Über das Erhabene" die vorletzte ästhetische Schrift, die von Schiller erschienen ist. Wir haben demnach eine späte, ausgereifte Formulierung (eines Teils) seiner ästhetischen Theorie vor uns, und wollen uns ihren Inhalt in aller Kürze und Bündigkeit vergegenwärtigen. Als "Wesen, welches will", verliere, so Schiller, der Mensch eben Wesentliches, wenn er Gewalt oder Zwang unterliege, wenn er also "nur muß und nicht will" (NA 21, 38). Nun muss jeder Mensch aber sterben und unterliegt damit letzten Endes einer natürlichen Gewalt. Da 1 Die Bearbeitung war nicht besonders gravierend, und die Vorbereitungen der Aufführung in Weimar (zuerst am 28. November 1801) für Schiller ziemlich unerquicklich (vgl. Peter-André Alt, Schiller. Leben-Werk-Zeit, Bd. 2, München 2000, S. 487f). Schiller hatte das Manuskript für den dritten Band seiner Kleineren prosaischen Schriften schon April 1801 an den Drucker schicken müssen, aber man darf davon ausgehen, daß die Nathan-Pläne schon länger gereift waren. Version vom 01.02.2006, 09:49 2 der Wille auf physischem Gebiet (hier: der Wille, weiter zu leben) also an offensichtliche Grenzen stößt, verweist Schiller auf die Möglichkeit des Menschen, Gewalt "dem Begriffe nach zu vernichten", und das heißt, "sich derselben freywillig unterwerfen". 2 Dies zu erreichen, könne die "moralische Kultur" dem Menschen helfen. Wir erfahren durch das Gefühl des Erhabenen, dass die Naturgesetze uns nicht vollständig bestimmen und sich der Zustand unseres Geistes nicht notwendig nach dem Zustand der Sinne richten muss. Wir haben, so Schiller, ein "selbstständiges Pincipium in uns", welches von allen körperlich-sinnlichen Einflüssen unabhängig ist (NA 21, 42). Bei einem Theaterbesuch kann der Mensch erfahren, "daß folglich zwey entgegengesetzte Naturen in uns vereiniget seyn müssen" (NA 21, 42): Die eine, die ihm als Bewohner der körperlichen Welt der Erfahrung zukommt, ist die Sinnlichkeit, der im übrigen auch der Verstand zuarbeitet; die andere, ganz andere, vernünftige Natur ist von den Gesetzlichkeiten der Sinnenwelt unabhängig und kann sich ihre Gesetze selbst geben. Die Doppelnatur des Menschen liegt im Bereich der Ästhetik der Dualität von Schönem und Erhabenem zugrunde, mit zwei je eigenen Begriffen von Freiheit. Beim Schönen stimmen Sinnlichkeit und Vernunft zusammen, der Mensch kann lustvoll Gerechtigkeit, Mäßigkeit und Standhaftigkeit üben. Es macht gerade den schönen Charakter aus, Lust an der Erfüllung seiner Pflichten zu finden. Die Freiheit bei der Schönheit liegt in der Übereinstimmung zwischen Trieb und Vernunftgesetz. 3 Beim Erhabenen hingegen-beim Großen und Ernsten,
Logic Colloquium '98
We formalize several ways of accounting, in the context of logically closed theories, for foundat... more We formalize several ways of accounting, in the context of logically closed theories, for foundationalist intuitions that underlie change operations applying to belief bases. A positive and a negative concept of entrenchment is defined on the basis of the structure of a given, possibly prioritized belief base. Only the latter, more fine-grained concept proves to be appropriate for a successful attempt at approximating base changes on the theory level. We investigate the question as to which degree we can comply with the fundamental intuition expressed by the various Filtering Conditions that say that all (and only) beliefs that are believed "just because" a retracted belief was believed should be withdrawn.
Das sogenannte Recht auf Nichtwissen
Minds and Machines
There are two prominent ways of formally modelling human belief. One is in terms of plain beliefs... more There are two prominent ways of formally modelling human belief. One is in terms of plain beliefs (yes-or-no beliefs, beliefs simpliciter), i.e., sets of propositions. The second one is in terms of degrees of beliefs, which are commonly taken to be representable by subjective probability functions. In relating these two ways of modelling human belief, the most natural idea is a thesis frequently attributed to John Locke: a proposition is or ought to be believed (accepted) just in case its subjective probability exceeds a contextually fixed probability threshold t<1$$t<1. This idea is known to have two serious drawbacks: first, it denies that beliefs are closed under conjunction, and second, it may easily lead to sets of beliefs that are logically inconsistent. In this paper I present two recent accounts of aligning plain belief with subjective probability: the Stability Theory of Leitgeb (Ann Pure Appl Log 164(12):1338–1389, 2013; Philos Rev 123(2):131–171, 2014; Proc Aristot Soc Suppl Vol 89(1):143–185, 2015a; The stability of belief: an essay on rationality and coherence. Oxford University Press, Oxford, 2015b) and the Probalogical Theory (or Tracking Theory) of Lin and Kelly (Synthese 186(2):531–575, 2012a; J Philos Log 41(6):957–981, 2012b). I argue that Leitgeb’s theory may be too sceptical for the purposes of real life.
Synthese, 2016
Pragmatists have argued that doxastic or epistemic norms do not apply to beliefs, but to changes ... more Pragmatists have argued that doxastic or epistemic norms do not apply to beliefs, but to changes of beliefs; thus not to the holding or not-holding, but to the acquisition or removal of beliefs. Doxastic voluntarism generally claims that humans (sometimes or usually) acquire beliefs in a deliberate and controlled way. This paper introduces Negative Doxastic Voluntarism according to which there is a fundamental asymmetry in belief change: (i) humans tend to acquire beliefs more or less automatically and unreflectively, but (ii) they tend to withdraw beliefs in a controlled and deliberate way. I first present a variety of philosophical, empirical and logical arguments for Negative Doxastic Voluntarism. Then I raise two objections against it. First, the apparent asymmetry may result from a confusion of belief with other doxastic attitudes like assumption, supposition, hypothesis or opinion. Second, the apparent asymmetry seems to vanish if we focus on doxastic states rather than just beliefs. Some rejoinders and their consequences for the vague concept of belief are sketched.
. We formalize several ways of accounting, in the context of logically closed theories, for found... more . We formalize several ways of accounting, in the context of logically closed theories, for foundationalist intuitions that underlie change operations applying to belief bases. A positive and a negative concept of entrenchment is defined on the basis of the structure of a given, possibly prioritized belief base. Only the latter, more fine-grained concept proves to be appropriate for a successful attempt at approximating base changes on the theory level. We investigate the question as to which degree we can comply with the fundamental intuition expressed by the various Filtering Conditions that say that all (and only) beliefs that are believed "just because" a retracted belief was believed should be withdrawn. 1 Introduction The problem dealt with in the present paper is best illustrated by an example. Example 1. Consider a theory K = Cn(#, #) which we want to contract with respect to #. Assume that K is generated by the belief base H = {#, #} and that # enjoys epistemic pr...
Journal of Logic and Computation, Jul 12, 2018
According to the Lockean thesis, a proposition is believed just in case it is highly probable. Wh... more According to the Lockean thesis, a proposition is believed just in case it is highly probable. While this thesis enjoys strong intuitive support, it is known to conflict with seemingly plausible logical constraints on our beliefs. One way out of this conflict is to make probability 1 a requirement for belief, but most have rejected this option for entailing what they see as an untenable skepticism. Recently, two new solutions to the conflict have been proposed that are alleged to be non-skeptical. We compare these proposals with each other and with the Lockean thesis, in particular with regard to the question of how much we gain by adopting any one of them instead of the probability 1 requirement, that is, of how likely it is that one believes more than the things one is fully certain of.
Journal of Logic and Computation, 2018
According to the Lockean thesis, a proposition is believed just in case it is highly probable. Wh... more According to the Lockean thesis, a proposition is believed just in case it is highly probable. While this thesis enjoys strong intuitive support, it is known to conflict with seemingly plausible logical constraints on our beliefs. One way out of this conflict is to make probability 1 a requirement for belief, but most have rejected this option for entailing what they see as an untenable skepticism. Recently, two new solutions to the conflict have been proposed that are alleged to be non-skeptical. We compare these proposals with each other and with the Lockean thesis, in particular with regard to the question of how much we gain by adopting any one of them instead of the probability 1 requirement, that is, of how likely it is that one believes more than the things one is fully certain of.
Information processing, rational beliefs and social interaction (10w2133) August 27-August 29, 20... more Information processing, rational beliefs and social interaction (10w2133) August 27-August 29, 2010 MEALS Coffee Breaks: As per daily schedule, 2nd floor lounge, Corbett Hall (included in workshop)
Cultures. Conflict - Analysis - Dialogue, 2007
This paper argues that problems of epistemology and problems of belief change are tightly interwo... more This paper argues that problems of epistemology and problems of belief change are tightly interwoven and that a successful analysis of knowledge depends on a proper solution of the problems of belief change Following Keith Lehrer we assume that what an agent knows at a certain instant is dependent upon how he is inclined to change his beliefs in time However two of Lehrers fundamental concepts personal justication and undefeated justication turn out be problematic I argue that systematic solutions to the problems must have recourse to a welldeveloped theory of belief change While this argument tries to establish that the theory of the static concept of knowledge needs help from the theory of the dynamics of belief it is nally argued that the reverse strategy should be followed in studies of belief change where the crucial epistemological distinction between foundationalism and coherentism proves useful for the analysis of belief representation and revision Keywords Epistemology theo...
Choice or selection functions are a classical device in the semantic study of conditionals, belie... more Choice or selection functions are a classical device in the semantic study of conditionals, belief revision and nonmonotonic reasoning (see for instance Lewis 1973, Alchourr6n, G£rdenfors and Makinson 1985, Delgrande 1987). It has been pointed out repeatedly that particular properties of choice functions are needed to yield some particular properties of the desired logics (Lewis 1973, p. 58; Nute 1980, p. 22, 1994, p. 370; Delgrande 1987, p. 114; Lamarre 1991, p. 362; Schlechta 1992, p. 682, and 1996; Rott 1993 and 1994; LindstrSm 1994). What is missing, however, is a unified treatment of nonmonotonic reasoning and belief revision in the general framework of rational choice that makes use of the vast body of literature available there. There are a lot of concepts, insights and techniques in rational choice that wait to be utitized by researchers working in logic, artificial intelligence and computer science.
The contraposing conditional 'If A then C' is defined by the conjunction of A > C and ... more The contraposing conditional 'If A then C' is defined by the conjunction of A > C and ~C > ~A, where > is a conditional of the kind studied by Stalnaker, Lewis and others. This idea has recently been explored, under the name 'evidential conditional', in a sequence of papers by Crupi and Iacona and Raidl, and it has been found of independent interest by Booth and Chandler. I discuss various properties of these conditionals and compare them to the 'difference-making conditionals' studied by Rott, which are defined by the conjunction of A > C and not ~A > C. I raise some doubts about Crupi and Iacona's claim that contraposition captures the idea of evidence or support.
The purpose of this paper is to link the logical theories of nonmonotonic reasoning and belief ch... more The purpose of this paper is to link the logical theories of nonmonotonic reasoning and belief change to the general theory of rational choice that derives from micro-economic theorizing.
In this paper I present the model of ‘bounded revision’ that is based on two-dimensional revision... more In this paper I present the model of ‘bounded revision’ that is based on two-dimensional revision functions taking as arguments pairs consisting of an input sentence and a reference sentence. The key idea is similar to the model of ‘revision by comparison’ investigated by Fermé and Rott (Artificial Intelligence 157, 2004). In contrast to the latter, however, bounded revision satisfies the AGM axioms as well as the Darwiche-Pearl axioms. Two onedimensional special cases are obtained by setting one argument of the two-dimensional revision operation to certain extremal values. Bounded revision thus fills the space between conservative revision (also known as natural revision) and moderate revision (also known as lexicographic revision). I argue that two-dimensional revision operations add decisively to the expressive power of qualitative approaches that refrain from assuming numbers as measures of degrees of belief.
In this paper I compare two dierent the models of two-dimensional belief change, namely 'revi... more In this paper I compare two dierent the models of two-dimensional belief change, namely 'revision by comparison' (Ferme and Rott, Artifi- cial Intelligence 157, 2004) and 'bounded revision' (Rott, in Hommage ` Wlodek, Uppsala 2007). These revision operations are two-dimensional in the sense that they take as arguments pairs consisting of an input sentence and a reference sentence. Two-dimensional revision operations add a lot to the expressive power of traditional qualitative approaches to belief revision and refrain from assuming numbers as measures of degrees of belief.
muß müssen" sagt der Jude Nathan zum Derwisch, und dieses Wort ist in einem weiteren Umfange wahr... more muß müssen" sagt der Jude Nathan zum Derwisch, und dieses Wort ist in einem weiteren Umfange wahr, als man demselben vielleicht einräumen möchte. Der Wille ist der Geschlechtscharakter des Menschen, und die Vernunft selbst ist nur die ewige Regel desselben. Vernünftig handelt die ganze Natur; sein Prärogativ ist bloß, daß er mit Bewußtseyn und Willen vernünftig handelt. Alle andere Dinge müssen; der Mensch ist das Wesen, welches will. (NA 21, 38) Mit diesen Worten beginnt Schiller seinen Aufsatz "Über das Erhabene". Vermutlich ist diese Schrift in der ersten Hälfte der 1790er Jahre entstanden. Eine genaue Datierung ist nicht mehr möglich. Man darf aber annehmen, dass sie Schiller zur Erstveröffentlichung im dritten Band seiner Kleineren prosaischen Schriften im Mai 1801 gründlich überarbeitet hat. Einen Hinweis darauf mag man darin sehen, dass er im Monat zuvor, einem lang gehegten Wunsche Goethes folgend, eine Bühnenbearbeitung von Lessings Nathan für die Aufführung im Weimarer Theater vorbereitet hatte. 1 Jedenfalls ist "Über das Erhabene" die vorletzte ästhetische Schrift, die von Schiller erschienen ist. Wir haben demnach eine späte, ausgereifte Formulierung (eines Teils) seiner ästhetischen Theorie vor uns, und wollen uns ihren Inhalt in aller Kürze und Bündigkeit vergegenwärtigen. Als "Wesen, welches will", verliere, so Schiller, der Mensch eben Wesentliches, wenn er Gewalt oder Zwang unterliege, wenn er also "nur muß und nicht will" (NA 21, 38). Nun muss jeder Mensch aber sterben und unterliegt damit letzten Endes einer natürlichen Gewalt. Da 1 Die Bearbeitung war nicht besonders gravierend, und die Vorbereitungen der Aufführung in Weimar (zuerst am 28. November 1801) für Schiller ziemlich unerquicklich (vgl. Peter-André Alt, Schiller. Leben-Werk-Zeit, Bd. 2, München 2000, S. 487f). Schiller hatte das Manuskript für den dritten Band seiner Kleineren prosaischen Schriften schon April 1801 an den Drucker schicken müssen, aber man darf davon ausgehen, daß die Nathan-Pläne schon länger gereift waren. Version vom 01.02.2006, 09:49 2 der Wille auf physischem Gebiet (hier: der Wille, weiter zu leben) also an offensichtliche Grenzen stößt, verweist Schiller auf die Möglichkeit des Menschen, Gewalt "dem Begriffe nach zu vernichten", und das heißt, "sich derselben freywillig unterwerfen". 2 Dies zu erreichen, könne die "moralische Kultur" dem Menschen helfen. Wir erfahren durch das Gefühl des Erhabenen, dass die Naturgesetze uns nicht vollständig bestimmen und sich der Zustand unseres Geistes nicht notwendig nach dem Zustand der Sinne richten muss. Wir haben, so Schiller, ein "selbstständiges Pincipium in uns", welches von allen körperlich-sinnlichen Einflüssen unabhängig ist (NA 21, 42). Bei einem Theaterbesuch kann der Mensch erfahren, "daß folglich zwey entgegengesetzte Naturen in uns vereiniget seyn müssen" (NA 21, 42): Die eine, die ihm als Bewohner der körperlichen Welt der Erfahrung zukommt, ist die Sinnlichkeit, der im übrigen auch der Verstand zuarbeitet; die andere, ganz andere, vernünftige Natur ist von den Gesetzlichkeiten der Sinnenwelt unabhängig und kann sich ihre Gesetze selbst geben. Die Doppelnatur des Menschen liegt im Bereich der Ästhetik der Dualität von Schönem und Erhabenem zugrunde, mit zwei je eigenen Begriffen von Freiheit. Beim Schönen stimmen Sinnlichkeit und Vernunft zusammen, der Mensch kann lustvoll Gerechtigkeit, Mäßigkeit und Standhaftigkeit üben. Es macht gerade den schönen Charakter aus, Lust an der Erfüllung seiner Pflichten zu finden. Die Freiheit bei der Schönheit liegt in der Übereinstimmung zwischen Trieb und Vernunftgesetz. 3 Beim Erhabenen hingegen-beim Großen und Ernsten,
Logic Colloquium '98
We formalize several ways of accounting, in the context of logically closed theories, for foundat... more We formalize several ways of accounting, in the context of logically closed theories, for foundationalist intuitions that underlie change operations applying to belief bases. A positive and a negative concept of entrenchment is defined on the basis of the structure of a given, possibly prioritized belief base. Only the latter, more fine-grained concept proves to be appropriate for a successful attempt at approximating base changes on the theory level. We investigate the question as to which degree we can comply with the fundamental intuition expressed by the various Filtering Conditions that say that all (and only) beliefs that are believed "just because" a retracted belief was believed should be withdrawn.
Das sogenannte Recht auf Nichtwissen
Minds and Machines
There are two prominent ways of formally modelling human belief. One is in terms of plain beliefs... more There are two prominent ways of formally modelling human belief. One is in terms of plain beliefs (yes-or-no beliefs, beliefs simpliciter), i.e., sets of propositions. The second one is in terms of degrees of beliefs, which are commonly taken to be representable by subjective probability functions. In relating these two ways of modelling human belief, the most natural idea is a thesis frequently attributed to John Locke: a proposition is or ought to be believed (accepted) just in case its subjective probability exceeds a contextually fixed probability threshold t<1$$t<1. This idea is known to have two serious drawbacks: first, it denies that beliefs are closed under conjunction, and second, it may easily lead to sets of beliefs that are logically inconsistent. In this paper I present two recent accounts of aligning plain belief with subjective probability: the Stability Theory of Leitgeb (Ann Pure Appl Log 164(12):1338–1389, 2013; Philos Rev 123(2):131–171, 2014; Proc Aristot Soc Suppl Vol 89(1):143–185, 2015a; The stability of belief: an essay on rationality and coherence. Oxford University Press, Oxford, 2015b) and the Probalogical Theory (or Tracking Theory) of Lin and Kelly (Synthese 186(2):531–575, 2012a; J Philos Log 41(6):957–981, 2012b). I argue that Leitgeb’s theory may be too sceptical for the purposes of real life.
Synthese, 2016
Pragmatists have argued that doxastic or epistemic norms do not apply to beliefs, but to changes ... more Pragmatists have argued that doxastic or epistemic norms do not apply to beliefs, but to changes of beliefs; thus not to the holding or not-holding, but to the acquisition or removal of beliefs. Doxastic voluntarism generally claims that humans (sometimes or usually) acquire beliefs in a deliberate and controlled way. This paper introduces Negative Doxastic Voluntarism according to which there is a fundamental asymmetry in belief change: (i) humans tend to acquire beliefs more or less automatically and unreflectively, but (ii) they tend to withdraw beliefs in a controlled and deliberate way. I first present a variety of philosophical, empirical and logical arguments for Negative Doxastic Voluntarism. Then I raise two objections against it. First, the apparent asymmetry may result from a confusion of belief with other doxastic attitudes like assumption, supposition, hypothesis or opinion. Second, the apparent asymmetry seems to vanish if we focus on doxastic states rather than just beliefs. Some rejoinders and their consequences for the vague concept of belief are sketched.
. We formalize several ways of accounting, in the context of logically closed theories, for found... more . We formalize several ways of accounting, in the context of logically closed theories, for foundationalist intuitions that underlie change operations applying to belief bases. A positive and a negative concept of entrenchment is defined on the basis of the structure of a given, possibly prioritized belief base. Only the latter, more fine-grained concept proves to be appropriate for a successful attempt at approximating base changes on the theory level. We investigate the question as to which degree we can comply with the fundamental intuition expressed by the various Filtering Conditions that say that all (and only) beliefs that are believed "just because" a retracted belief was believed should be withdrawn. 1 Introduction The problem dealt with in the present paper is best illustrated by an example. Example 1. Consider a theory K = Cn(#, #) which we want to contract with respect to #. Assume that K is generated by the belief base H = {#, #} and that # enjoys epistemic pr...