November 17, 2011, Pure and Applied Logic Colloquium
Dana Scott, Carnegie Mellon University
Mixing Modality and Probability
Reception: 4:00-4:35 DH 4301, Talk: 4:45-6:00 BH A53
Abstract: Many models for various modal logics have been given over the years. The author saw that the complete Boolean algebra of measurable subsets of the unit interval modulo sets of measure zero retains a topological structure. This is possible because working modulo null sets does not always identify open and closed sets. Therefore, a non-trivial Boolean-valued model of the Lewis modal system S4 is obtained (recently proved complete for propositional logic by others). The author has spoken about this semantics at CMU in the past, but he still feels there should be applications of the logic to basic ideas of probability. For this presentation a simplified description of semantics for a second-order system will be given which allows some possible insights into modeling randomness in a general, logical way.
November 19-20, 2011, Center for Formal Epistemology Colloquium
Commemorative Colloquium for Horacio Arlo-Costa
Speakers:
Cleotilde Gonzales, Carnegie Mellon, Social and Decision Sciences
Jeff Helzner, Columbia University
Vincent Hendricks, University of Copenhagen, Editor in Chief Synthese
Eric Pacuit, University of Maryland, CFE Fellow
Rohit Parikh, CUNY
Paul Pedersen, Carnegie Mellon University
Scott Shapiro, Yale Law School
Gregory Wheeler, University of Lisbon
December 8, 2011, Philosophy Colloquium
Risto Hilpinen, University of Amsterdam
TBA
Reception: 4:00-4:35 DH 4301, Talk: 4:45-6:00 BH A53
November 5, 2011, Center for Formal Epistemology Workshop
In Search of Answers: The Guiding Role of Questions in Discourse and Epistemology
4625 Wean Hall
Speakers:
Jeroen Groenendijk, University of Amsterdam
Craige Roberts, Ohio State University
Mandy Simons, Carnegie Mellon University
Hanti Lin, Carnegie Mellon University
Kevin T. Kelly, Carnegie Mellon University
November 3, 2011, Philosophy Colloquium
Jeroen Groenendijk, University of Amsterdam
Inquisitive Semantics and Pragmatics
Reception: 4:00-4:35 DH 4301, Talk: 4:45-6:00 BH A53
Abstract: In this talk I will provide an introduction to inquisitive semantics, but I will largely do so by not considering inquisitive semantics, but proto-inquisitive semantics. This is how I now call the partition semantics for a first-order logical language with questions that can be found in The Logic of Interrogation, my 1999 SALT-paper. In this language there are indicatives and interrogatives, only sentences in the rst category can be informative, and only those in the second category can be inquisitive. In inquisitive semantics not all questions correspond to partitions, which I will briefly motivate by considering conditional questions. Also, logical languages that the semantics is applied to are standard languages in which no syntactic distinction between indicatives and interrogatives is made. Instead, assertions and questions are characterized semantically. And, not all sentences belong to one of these two categories, some sentences are hybrid, sentences which are both informative and inquisitive. Plain disjunction and existential quantification deliver such hybrid sentences. For several reasons this is interesting from a linguistic point of view. What I will do in the talk is reformulate proto-inquisitive semantics using the concepts and tools from inquisitive semantics. This is useful as such, because what results, though it remains equivalent, is a conceptually more transparant and a more standard system. More importantly, having the two systems in the same format makes it easier to compare them, and detect precisely what the real dierences are. This leads to a better understanding of both proto- and real inquisitive semantics. An important feature of both proto- and real inquisitive semantics is that they come with logical pragmatical notions concerning the coherence of discourse, relatedness of sentences to each other, other than the standard logical relation of entailment. Answerhood is just a special case of what is covered by these notions. I will present a new version of the logical notion of a compliant response to an initiative that the comparison of the two semantics has led to. Central to the talk is that I want to show that and how inquisitive semantics offers a new notion of meaning that is richer than that of a classical proposition modeled as a set of possible worlds, the worlds where a sentence is true. Our propositions, which cover both informative and inquisitive content, are modeled as sets of possibilities, which correspond to states of the common ground where a sentence is supported. We can now look upon a proposition as a proposal to the participants in a conversation to update the common ground in one or more ways, the alternative possibilities covered by the proposition. Arguably, this is a notion of meaning that, unlike the classical one, is inherently linked to the interactive communicative use of language. I will further motivate and sharpen this new concept of meaning in the talk.
October 13, 2011, Pure and Applied Logic Colloquium
Rick Statman, Carnegie Mellon University
A New Type Assignment for Strongly Normalizable Terms
Reception: 4:00-4:35 DH 4301, Talk: 4:45-6:00 BH A53
Abstract: Intersection types are very interesting especially in their use for proving untyped terms to be strongly normalizable. However, we view them first as types and second, via the Curry-Howard iso-morphism, as formulae. That is, we consider the "types as formulae" direction of the isomorphism. We would like to extend the "formulae as types" direction of Curry-Howard to include all strongly normalizable terms. We shall do this by considering a natural deduction formulation of a definitional extension of the intuitionistic theory of monadic predicates and show that the untyped lambda terms with types (under the Curry-Howard isomorphism) are precisely the strongly normalizable terms.
October 6, 2011, Center for Ethics and Policy Colloquium,
Adina Roskies, Dartmouth College
Rethinking the threat from brain scans in the courtroom
Reception: 4:00-4:35 DH 4301, Talk: 4:45-6:00 BH A53
Abstract: Both empirical data and philosophical considerations suggest that brain scans used as evidence in the courtroom may be biasing or misleading. However, recent studies suggest this view is mistaken. In this talk I explain the reasons for the expectation that neuroimages may be misleading, and review the studies that contradict it. I offer an explanation for the totality of the seemingly contradictory evidence, and argue that this has implications for the admissibility of neuroimaging in the courtroom.
September 29, 2011, Center for Ethics and Policy Colloquium,
Darrel Moellendorf, Claremont Graduate School
Climate Change and Human Rights: Assessing Some Philosophical Challenges
Reception: 4:00-4:35 DH 4301, Talk: 4:45-6:00 BH A53
Abstract: In this paper I set out an argument, invoking human rights, in defense of the duties to mitigate and provide adaptation to climate change. I look at five challenges to the human rights argument, three of which have been pressed in the literature on conceptual grounds, and two of which I develop on normative grounds. I present what I think are satisfactory responses to the three conceptual challenges but I argue that the normative challenges are more compelling. The human rights argument does not help us to understand well our duties to future generations to mitigate and provide adaptation for climate change. The problems with the human rights argument suggest that a more promising approach is to understand these duties as matters of intergenerational distributive justice.
September 28, 2011, Informal Afternoon Talk
Yasuo Deguchi, Kyoto University
Kant and Segner: Kant's philosophy of Mathematics and 18th Century German Arithmetic
3:30-5:00 BH 150
Abstract: Kant is taken as one of the first persons who used the word 'construction' in the current philosophical sense, and therefore is deemed to be an originator of constructivism. In my view, what he did was to generalize the idea of `geometrical construction' to cover other basic operations in different fields of mathematics; particularly and crucially, the 'successor operation' in arithmetic. In other words, it was a decisive step forward for 'the birth of construction in Kant' to view the 'successor operation' as being analogous to geometrical construction in a sense. This crucial step was backed up by Kants' conception of the
'successor operation' or 'number' as a 'schema'. His concept of
number-as-schema was not standard in 18th century German arithmetic. But we can find its prototype in some writings of Johann Andreas von Segner (1704-77), a German mathematician/scientist, whose 'Arithmetik' Kant referred to, in a crucial passage. My talk will focus on how Segner's view on number contributed to the birth of construction in Kant'.
September 28, 2011, Informal Lunchtime Talk
Yukinori Takubo, Kyoto University
Modal Questions in Korean and Japanese
12:00-1:30 BH 150
Abstract: In this talk we will discuss constraints on questions with modals in Korean and Japanese. In Korean there are two expressions for expressing future: -keyss and -ul kes-i-(future adnominal form+ thing+copula). They can be used more or less in the same way, as in (1)a,b, when they express intention.
1 ) a. Nayil tangsin-un o-keyss-upni-kka?
tomorrow you-TOP come-keyss-HON-Q
'Are you coming tomorrow?
b. Nayil tangsin-un o-l kes-i-pni-kka?
tomorrow you-TOP come-l kes-i-HON-Q
'Are you coming tomorrow?
The differences begin to emerge when they are attached to non-volitional predicates as in (2).
2 ) a. (Situation:the speaker greets a farmer looking up at the sky)
Nayil pi-ka o-keys-ssupni-kka?
tomorrow rain-NOM come-keyss-HON-Q
'Will it rain tomorrow?'
b. (same as in a)
*Nayil pi-ka o-l kes-i-pni-kka?
tomorrow rain-NOM come-l kes-i HON-Q
'Will it rain tomorrow?'
(2)b cannot naturally be interpreted as an epistemic question asking if the addressee thinks it will rain, in contrast to (2)a, which can. In a very special context, (2)b can be coerced to be interpreted as asking someone who can control rain, e.g. a deity or a scientist who is conducting an artificial rain experiment.
The distribution of -ul kes i- can be accounted for if we assume that it expresses epistemic necessity. As can be seen in (3)-(4), sentences expressing epistemic modality cannot be questioned in English.
3 ) a. It {must/may} rain in the afternoon.
b. ??{Must/May} it rain in the afternoon?
Sentences expressing epistemic modality can be made into a question by changing it into a meta-question, i.e. a question asking about the modal force itself: whether it is necessary, possible or not. In Japanese, such a meta-question can be formed by adding no, the complementizer. We will show that the only way that ul kes-i can be interpreted as a meta-question is to interpret it as expressing the predetermined future, thereby accounting for the special coerced interpretation of ul kes-i .
September 26, 2011, Center for Ethics and Policy Colloquium,
Alex Voorhoeve, London School of Economics
Decide as You Would with Full Information! An Argument against the Ex Ante Pareto Principle
Venue: TBA
Abstract: The ex ante Pareto principle requires that if a first alternative has greater expected value for each person than second alternative, the first alternative ought to be preferred. We examine cases in which a first alternative has greater expected value for each person, but we know that under this alternative one person will, ex post, end up worse off than others. We argue that, in such cases, the ex ante Pareto principle is of doubtful validity, because it relies on incomplete information about what is in the interests of each person. We argue that, whenever possible, it is better to rank alternatives as we *would* rank them if we had full information about how individuals will be affected.
September 22, 2011, Philosophy Colloquium,
Jan-Willem Romeijn, CFE Fellow, University of Groningen
Observations and Objectivity in Statistics
Reception: 4:00-4:35 DH 4301, Talk: 4:45-6:00 BH A53
Abstract: Observations are generally agreed to be laden with theory, and hence not entirely objective. It may be thought that if the data are objective anywhere, it is in statistics. In this paper I argue against this and reveal two ways in which statistical inference is affected by the theory-ladenness of observations. The first of these concerns well-known violations of the likelihood principle, namely in hypothesis testing and optional stopping. It appears that we can represent these violations as cases in which the likelihood principle is adhered to. But to achieve this, we have to accept that the content of the observations depends on the statistical hypotheses under consideration. Another way in which statistical data may be theory-laden concerns the influence of priors on how the observations affect our judgment over the hypotheses. I will discuss two cases in which the implicit or explicit adoption of a prior has specific implications for what is concluded from the observations, one in regression analysis and one in causal modelling. Rather than seeing these results in a negative light, as damaging to the objectivity of statistical methods, I think that they invite us to rethink the role of theory-ladenness. I argue that it is exactly because of the theory-ladenness that we can learn from the data. In grand philosophical terms, I argue for a rationalist twist to the empiricist orientation of the philosophy of statistics.
September 15, 2011, Philosophy Colloquium:
Abstract: A rational belief must be grounded in the evidence available to an agent. However, this relation is delicate, and it raises interesting philosophical and technical issues. Modeling evidence requires richer structures than found in standard epistemic semantics where the accessible worlds aggregate all reliable evidence gathered so far. Even recent more finely-grained plausibility models ordering the epistemic ranges identify too much: belief is indistinguishable from aggregated *best* evidence. In this talk, I will discuss a recent paper by myself and Johan van Benthem where we add evidence structure to standard models of belief, in the form of families of sets of worlds. We show how these more fine-grained models support natural actions of ``evidence management'', ranging from update with external new information to
internal rearrangement.
September 8, 2011,Philosophy Colloquium:
Abstract: How should one decide which logic is correct? I will answer the question by giving a very general account of rational theory choice, and arguing that it applies to the choice of logic. A feature of the account is that it has no role for the a priori. This feature will come in for special discussion.
September 9, 2011,Informal Lunchtime Talk
Abstract: Madhyamaka was one of the two major schools of Indian Mahayana Buddhist philosophy, which had an enormous impact on all subsequent Mahayana Buddhisms. An important aspect of their position was that there is no ultimate ground to reality, every thing being dependent on other things. This allows them to shape a metaphysics that is neither realist nor idealist, but "goes between the horns" of these two views. In this talk I will explain all this. (I will not presuppose any background knowledge of Asian philosophical traditions.)
June 24-26 Episteme Conference, held at CMU.Local arrangements.
June 22, 2011, Informal Lunchtime Talk:
Emmanuel J. Genot, University of Lund
A Little Semantics is a Dangerous Thing
12:00-1:00 DH4303
Abstract: The aim of this paper is to show that the dismissal of logical models of reasoning, as empirically inadequate, and relying on too strong idealizations, comes from an insufficient understanding of the resources of formal semantics. I first review arguments from cognitive psychology, backing the use of semantic methods. Then I propose a new semantic account of Hintikka's interrogative tableaux, capturing reasoning of agents with very limited cognitive resources. [Stenning&Van Lambalgen,2007] show that the often argued non-logicality of human reasoning results from the assumption of uniqueness of logic, despite the plurality of logics. From a pluralistic point of view, choice of an appropriate logic is context-dependent. When contextual parameters are unclear, distinct empirical agents may "default" to different logics. Conversely, when they are clearly set, agents' performances become uniform, conforming to the same logic. The appropriate logical standard is in turn identified through its semantic, with the semantic structure mirroring relations between objects reasoned about. Logical pluralism supports the objectivity of logic, and its relevance for empirical cognitive science. Hintikka also has argued, on semantic grounds, that the Semantic Tableau Method yields a model of reasoning, once extended to represent "questions" as means of information gathering.(see [Hintikka et al., 1999]). The resulting Interrogative Tableaux embody reasoning about epistemic alternatives (or scenarios). Hintikka furthermore sketches a game-theoretic epistemic semantics, without however fully developing it. His ideas depart from standard game theory, in assuming that agents use "local" strategic principles. A game-theoretic account of semantic entailment assuming players with limited awareness of the future history of the game, following e.g. [Halpern&Rêgo2006], yields a two-player game between an initial verifier of the premises, Abelard, and an initial verifier of the conclusion, Eloise, where
Eloise has a winning strategy iff every model of the premises Abelard can choose during the game verifies the conclusion. When this is so, the game reaches a fixed-point, which is identifiable by the players given only the past history of the game. If Abelard wins, then the game also reaches a fixedpoint, which cannot however always be identified, since it depends on the future of the game. Constraining the Abelard's choices by information (answers) about the underlying state of Nature, captures Hintikka's interrogative reasoning. Only minimal awareness of the future history of the game, is required for "local" strategies to matc exactly the interrogative tableau rules. The existence and identifiability of fixed-points introduce
consideration pertaining to formal learning theory. I conclude that interrogative logic, endowed with this epistemic game-theoretic semantics, is at its core learning-theoretic, and fully vindicates Hintikka's claim that interrogative logic is an empirically adequate model of human reasoning.
May 14-15 CSLI-CFE-San Francisco State workshop on Logic and Formal Epistemology held at CSLI, Stanford.
May 5, 2011, Philosophy and CMU-Pitt Program in Computational Biology Joint Colloquium
Ioannis Tsamardinos, University of Crete
Toward Integrative Causal Analysis of Heterogeneous Datasets and Prior Knowledge
4:15-6:00 BH A53
April 22, 2011, Informal Lunchtime Talk
Rachel Briggs, University of Sydney and NYU
Two Interpretations of the Ramsey Test
Abstract: According to the Ramsey test, a person should accept a conditional to the extent that she would accept the consequent on the supposition that the antecedent holds. There are two attractive ways of interpreting the Ramsey test: Adams’ thesis, which states that the probability of a conditional is the conditional probability of the consequent given the antecedent, and Stalnaker semantics, which states that a conditional is true at a world w just in case its consequent is true at all closest antecedent worlds to w. Unfortunately, a well-known class of triviality theorems shows that when the two interpretations of the Ramsey test are combined, they entail seemingly absurd triviality results. Stefan Kaufmann has proposed (for reasons largely independent of the triviality theorems) a revised version of Adam's; thesis, which I call Kaufmann's thesis. I prove that combining Kaufmann&'s thesis with Stalnaker's semantics leads to local triviality results, which seem just as absurd as the original triviality results. Luckily, Stalnaker semantics can be revised too: in particular, it can be replaced with a generalized imaging semantics. I argue that combining Kaufmann's thesis with generalized imaging semantics provides a way of defanging the local triviality results, not by undercutting the arguments for them, but by explaining why they are not as philosophically problematic as they seem.
April 21, 2011, Philosophy Colloquium:
Mic Detlefsen, Notre Dame University
Freedom in Mathematics
Reception: 4:00-4:35 DH 4301, Talk: 4:45-6:00 BH A54
April 7, 2011, Philosophy Colloquium:
Michiel van Lambalgen, University of Amsterdam
Logical Modelling of Cognitive Processes: the Case of Autism
Reception: 4:00-4:35 DH 4301, Talk: 4:45-6:00 BH A53
April 6, 2011, Informal Lunchtime Talk:
Michiel van Lambalgen, University of Amsterdam
A Formalisation of Kant's Transcendental Logic
12:00-1:00 DH4303
March 31, 2011, Philosophy Colloquium:
Anil Gupta, University of Pittsburgh
Conditionals in Theories of Truth
Reception: 4:00-4:35 DH 4301, Talk: 4:45-6:00 BH A53
Abstract: I will compare the treatment of conditionals in two accounts of truth, revision theory and Hartry Field's recent proposal.
March 28, 2011, Center for Ethics and Policy Colloquium:
Gusfaf Arrhenius, Stockholm University
The Impossibility of a Satisfactory Population Ethics
BH 136-A (Adamson Wing)
March 17, 2011, Philosophy Colloquium:
Hannes Leitgeb, Ludwig-Maximiliens-University
A Theory of Propositions and Truth
Reception: 4:00-4:35 DH 4301, Talk: 4:45-6:00 BH A53
March 16, 2011, CFE Symposium on Uncertain Acceptance
Hannes Leitgeb, Ludwig-Maximiliens-University
The Lockean Thesis Revisited
12:00-1:00 DH4303
Horacio Arlo-Costaand Paul Pedersen, Carnegie Mellon University
Reducing Belief To Degrees of Belief: A General Theory of Probability Cores
1:00-2:00 DH4303
Hanti Lin and Kevin T. Kelly
Propositional Reasoning that Tracks Probabilistic Reasoning
2:00-3:00 DH4303
March 3, 2011, Philosophy Colloquium:
Wayne Myrvold, University of Western Ontario
Maxwell and a Third Second Law of Thermodynamics.
Reception: 4:00-4:35 DH 4301, Talk: 4:45-6:00 BH A53
January 20, 2011, Philosophy Colloquium:
Cosma Shalizi, Carnegie Mellon University
Praxis and Ideology in Bayesian Statistics
Reception: 4:00-4:35 DH 4301, Talk: 4:45-6:00 BH A53
Abstract: A substantial school in the philosophy of science identifies Bayesian inference with inductive inference and even rationality as such, and seems to be strengthened by the rise of Bayesian statistics in applications. In this talk, I hope to persuade you that the most successful practices of Bayesian statistics do not actually support that philosophy but rather accord much better with sophisticated forms of hypothetico-deductivism. Drawing on the literature on the consistency of Bayesian updating and also on experience of applied work, I examine the actual role of prior distributions in Bayesian models, and the crucial aspects of model checking and model revision, which fall outside the scope of Bayesian confirmation theory. I argue that good Bayesian practice is very like good frequentist practice; that Bayesian methods are best understood as regularization devices; and that Bayesian inference is no more inductive than frequentist inference, i.e., not very. At best, the inductivist view has encouraged researchers to fit and compare models without checking them; at worst, theorists have actively discouraged practitioners from performing model checking because it does not conform to their ideology. Based on joint work with Andrew Gelman (http://arxiv.org/abs/1006.3868)
December 2, 2010, Informal Lunchtime Talk
Michael Shaffer, St. Cloud State University
Knowledge, Rationality, and Scientific Idealization
December 1, 2010, Center for Formal Epistemology Workshop
Speakers
Ralph Hertwig, University of Basel
Jonathan Leland, National Science Foundation
Paul Pedersen, Carnegie Mellon University
Elke Weber, Columbia University
Jerome Busemeyer, Indiana Universityi at Bloomington
Coty Gonzalez, Carnegie Mellon University
Tim Pleskac, Michigan State University
J.D. Trout, Loyola University
Horacio Arlo-Costa, Carnegie Mellon University
Discussants
David Danks, Carnegie Mellon University
Kevin Kelly, Carnegie Mellon University
Richard Samuels, Ohio State University
November 22, 2010, Center for Ethics and Policy (CEP) Colloquium
Russell Powell, Oxford University
In Genes We Trust: Germ-Line Modification and the Preservation of Human Good
November 18, 2010, Philosophy Colloquium
Timothy Williamson, Wykeham Professor of Logic, Oxford University
Improbable Knowledge
Abstract: The paper argues that failures of the KK principle (that if one knows something, one knows that one knows it) can occur in extreme form: one can know p even though it is almost certain on one’s evidence that one does not know p. For related reasons, p can be part of one’s evidence even though it is almost certain on one’s evidence that p is not part of one’s evidence, and it can be rational for one to do A even though it is almost certain on one’s evidence that it is not rational for one to do A. The argument will use formal models from epistemic logic but will not assume previous knowledge of epistemic logic. It will be argued that models of the relevant type are adequate approximations to realistic, rather everyday situations.
November 17, 2010, Informal Lunchtime Talk
Timothy Williamson, Wykeham Professor of Logic, Oxford University
Necessitism, Contingentism and Plural Quantification
October 19, 2010, Nagel Lecture
Brian Skyrms, U.C. Irvine
Naturalizing the Social Contract
October 21, 2010, Nagel Lecture
Brian Skyrms, U.C. Irvine
Signals: Evolution, Learning and Information
October 22, 2010, Nagel Lecture
Brian Skyrms, U.C. Irvine
On the Dynamics of Signaling
October 7, 2010, Philosophy Colloquium
Kevin Knuth, SUNY Albany.
Quantification and the Origin of Physical Law: The Feynman Complex Formalism of Quantum Mechanics
Abstract: It is a commonly held belief that physical laws reflect an underlying order in the universe. If this is the case, then it is possible that significant aspects of physical law can be derived from a precise specification of that order. In this talk, I show that this is indeed the case. Given a set of elements, which comprise the topic of discourse, and a binary ordering relation, one can construct a partially ordered set and often a lattice. The symmetries possessed by the lattice structure induced by the ordering relation impose strong constraints on any quantification scheme designed to map elements to real numbers or real number pairs. These constraint equations give rise to what we recognize as physical laws.
References:
1. Goyal P., Knuth K.H., Skilling J. 2010. Why Quantum Theory is Complex, Phys. Rev. A 81, 022109.
arXiv:0907.0909v3 [quant-ph]
2. Knuth K.H., Skilling J. 2010. Foundations of inference.
arXiv:1008.4831v1 [math.PR]
3. Knuth K.H., Bahreyni N. 2010. A derivation of special relativity from causal sets.
arXiv:1005.4172v2 [math-ph]
September 30, 2010, Distinguished Alumnus Lecture
Robert Malkin, Senior Software Engineer, Google
Predicting Bounce Rates in Sponsored Search
September 24, 2010, Informal Lunchtime Talk
Yasuo Deguchi, University of Kyoto
Three Prisoners Problem and Likelihoodism
Robert Batterman, University of Pittsburgh
Explaining Regularities: The Need for Singular Behavior
June 26-27, 2010, CFE Opening Celebration