Carnegie Mellon University
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Kevin Kelly

Kevin Kelly

Professor
Director of the Center for Formal Epistemology

Address
5000 Forbes Avenue
Pittsburgh, PA 15213

Research Areas

Ockham's razor and realism

When faced with several theories compatible with the data, scientists tend to prefer the simplest and cite Ockham's razor; as the justification. But what is empirical simplicity and how could a systematic bias toward it help one find the truth without invoking the (circular) assumption that the truth is simple? I propose that simplicity reflects the ability of nature to force a truth-conducive scientist through successive revisions of her theory and that Ockham's razor minimizes those revisions in the worst case. The underlying mathematical framework is point set topology.This ongoing work is currently supported by a three year grant from the John Templeton Foundation. Visit the Ockham project site.

Publications

Qualitative belief and the lottery paradox

This is joint work with Hanti Lin. In traditional epistemology, semantics, epistemic logic, artificial intelligence planning, non-monotonic reasoning, and belief revision theory, one speaks qualitatively of belief in a propostion. Bayesians speak quantitatively of degrees of belief in propositions. How do the two relate? A standard view is that uncertain, qualitative beliefs pass a sufficiently high probability threshold. That idea is subject to the celebrated lottery paradox: given a sufficiently large lottery, one would believe of each ticket that it loses and one would also believe that some ticket wins. It is also prone to a pair of less familiar, but more stubborn diachronic paradoxes. First, you accept a proposition and observe what it entails and then drop it, contrary to scientific method. Second, you would accept a proposition if A and you would also accept it if not-A, but you don't accept it in advance. Based on ideas from projective geometry, we propose an alternative acceptance rule that eludes all of the paradoxes old and new. We also show that it there is a way to revise your qualitative beliefs that tracks Bayesian conditioning exactly and that, moreover, that standard approaches to qualitative belief revision in philosophy and artificial intelligence can’t do it.

Publications

Learning semantics for epistemic logic

The standard models for epistemic logic simply assign a true, logically closed "knowledge state" to each individual. That approach occasions some three important objections. (1) Knowledge is assumed to be ideally closed under logical consequence. (2) The semantics does not explain any non-trivial epistemological principles. (3)  The models do not relate knowledge to learning or information. All three objections can be met by modeling knowledge as the culmination of a concrete learning process extended through time and driven by inputs from nature and other agents---i.e., by a concrete, computational learning semantics for inductive knowledge.

Publications

Analogies between emplirical and formal reasoning

David Hume distinguished sharply between "relations of ideas" and "matters of fact". Contemporary, Bayesian accounts of rationality maintain that tradition: you are forgiven for not knowing if the sun will rise tomorrow, whereas you are condemned for not knowing whether your computer will halt tomorrow. But the two problems look pretty much the same---just because the cursor has been blinking on the screen for an hour doesn't mean that the answer won't flash on the screen in the very next second. How would epistemology look if we said that uncomputability and the problem of induction are essentially the same, rather than radically different?

Publications

The learning power of belief revision

Belief revision theory is supposed to be a theory of how to rationally alter one's beliefs in light of new information. One might naturally suppose that rationality includes truth conduciveness as at least one dimension. Astoundingly, nobody ever asked whether the rules proposed for rational belief revision are particularly good at finding true beliefs. What if one did ask?

Publications

Learning theory and the philosophy of science

Confirmation is supposed to be evidential relevance. But to what end? Learning procedures carry some guarantee of arriving at the right answer eventually. What does the philosophy of science look like when one shifts attention from intuitions about confirmation by evidence to an objective analysis of the truth-conduciveness of scientific methods?

Publications

  • "Argument, Inquiry, and the Unity of Science", Journal of the Asiatic Society, B.J. Mukherjee, ed. 2012.
  • "Learning Theory and Epistemology",  in  Handbook of Epistemology, I. Niiniluoto, M. Sintonen, and J. Smolenski, eds.  Dordrecht: Kluwer, 2004.
  • "The Logic of Success",  British Journal for the Philosophy of Science, special millennium issue, 51, 2001, 639-666. Reprinted in Philosophy of Science Today, P. Clark and K. Hawley eds., Oxford: Oxford University Press, 2004.
  • "Naturalism Logicized", in  After Popper, Kuhn and Feyerabend: Current Issues in Scientific Method, R. Nola and H. Sankey, eds, 34 Dordrecht: Kluwer, 2000, pp. 177-210. Reprinted in Philosophy of Science Today, P. Clark and K. Hawley eds., Oxford: Oxford University Press, 2004.(with O. Schulte and C. Juhl)
  • "Learning Theory and the Philosophy of Science", Philosophy of Science 64: 1997, pp. 245-267.
  • The Logic of Reliable InquiryOxford: Oxford University Press, 1996.
  • (With C. Juhl and C. Glymour),"Reliability, Realism, and Relativism'', in Reading Putnam, P. Clark, ed., London: Blackwell, 1994, 98-161.
  • "Learning Theory and Descriptive Set Theory'', Logic and Computation, 3:1, 1993, pp. 27-45.

Infinite methodological regresses

Learning often requires prior assumptions to "prime the pump" of inquiry. But then those assumptions can come into question. One can apply an inductive method to that question that requires its own prior assumptions. And so forth. What distinguishes useful such regresses from "vicious" ones? The virtuous regresses can be "collapsed" or inter-reduced with single methods and then the value of the regress can be identified with that of the single method.

Publications

  • "How to Do Things with an Infinite Regress", in Philosophy of Mathematics and Induction, V. Harazinov, M. Friend, and N. Goethe, Dordrecht: Springer, 2007.
  • "Naturalism Logicized", in After Popper, Kuhn and Feyerabend: Current Issues in Scientific Method, R. Nola and H. Sankey, eds, 34 Dordrecht: Kluwer, 2000, pp. 177-210.

Courses

Undergraduate
  • 80-105: Freshman Seminar on Mysticism
  • 80-120: Reflections on Science
  • 80-201: Epistemology
  • 80-202: Metaphysics
  • 80-210: Self-paced Introduction to Logic
  • 80-220: Philosophy of Science
  • 80-251: Ancient Philosophy
  • 80-252: Medieval Philosophy
  • 80-252: History of Modern Philosophy
  • 80-276: Philosophy of Religion
  • 80-310: Logic and Computability
  • 80-311: Logic and Artificial Intelligence
  • 80-311: Goedel and Undecidability
  • 80-351: Kant
  • 80-312: Probability and Artificial Intelligence
 Graduate
  • 80-812: Seminar on Formal Learning Theory
  • 80-411/711: Computability and Learnibility
  • 80-411/711: Descriptive Set Theory
  • 80-518: Epistemology Seminar
  • 80-521: Seminar on Formal Epistemology
  • 80-524: Ockham's Razor
  • 80-602: Proseminar

Talks

  • “The Topology of Inquiry”, CMU Summer School, Carnegie Mellon University, Summer 2014.
  • (With Konstantin Genin) “A Prior-free Justification of Ockham’s Razor in Causal Discovery”, Workshop on Simplicity and Causal Discovery, Center for Formal Epistemology, Carnegie Mellon University, Summer 2014.
  • (With Konstantin Genin) “Ockham’s Razor and Statistical Model Selection”, Models and Simula- tions 6, Notre Dame, Autumn 2014.
  • (With Konstantin Genin and Hanti Lin) “A Topological Theory of Empirical Simplicity”, Philoso- phy of Science Biennial Meeting, Chicago, Autumn 2014.
  • (With Konstantin Genin) “An Epistemic Justification of Ockham’s Razor”, Rene Descartes Lec- tures, Tilburg, Netherlands, Autumn 2014.
  • (With Hanti Lin) “Acceptance that Tracks Conditioning”, Synthese Conference, Amsterdam, Au- tumn 2014.
  • (With Konstantin Genin and Hanti Lin) “Realism, Rhetoric, and Reliability” Workshop on Induc- tion, Abduction, Belief Revision, and Realism, National Technical University of Athens, Greece Winter, 2014.
  • (With Konstantin Genin) “A Topological Theory of Simplicity, Ockham’s Razor, and Theoretical Inference”, National Technical University of Athens, Greece, Winter 2014.
  • (With Konstantin Genin) “Simplicity, Truth, and Topology”, Dept. of Logic and Philosophy of Science, U. C. Irvine, Spring 2015.
  • (With Konstantin Genin) “A Reliabilist Justification of Ockham’s Razor”, Dept. of Philosophy, Kobe University, Japan, Summer 2015.
  • (With Konstantin Genin) “A Non-circular Justification of Ocham’s Razor in Theoretical Inference”, Dept. of Informatics, University of Kyoto, Japan, Summer 2015.
  • (With Konstantin Genin) “Rhetoric, Reliability, and Inductive Inference”, Dept. of Philosohy, University of Kyoto, Japan, Summer 2015.
  • (With Konstantin Genin) “Ockham’s Razor and Truth”, Dept.  of Philosophy, University of Hokkaido, Japan, Summer 2015.
  • (With Konstantin Genin) “Topology and Inquiry”, Dept. of Philosophy, Summer School in Logic and Formal Epistemology, Summer 2015.
  • (With Konstantin Genin) “New Foundations for Ockham’s  Razor  in  Statistical  Inductive  Infer- ence, with Applications to Causal Discovery from Non-experimental Data”, Max Planck Institute, Tu¨bingen, Germany, Summer 2015.
  • (With Konstantin Genin) “Simplicity, Truth, and Topology”, CLMPS, Helsinki, Finnland, Summer 2015.
  • (With Konstantin Genin) “Topology, Simplicity, and Statistics”, Dept. of Philosophy, Roskilde, Denmark, Summer 2015.
  • (With Konstantin Genin) “Simplicity, Learning, and Topology”, Dept. of Philosophy, Carnegie Mellon, 30 Year Anniversary Celebration, Summer 2015.
  • (With Konstantin Genin) “Theory Choice, Belief Revision, and Learning”, ILLC, University of Amsterdam, Netherlands, Summer 2015.
  • (With Konstantin Genin) “Simplicity and Scientific Questions”, Center for Formal Epistemology Workshop on Questions and Attitudes, Summer 2016.
  • (With Konstantin Genin) “A Topological Semantics for Inductive Knowledge”, Academia Sinica, Taipei, Taiwan, Summer 2016.
  • (With Konstantin  Genin)  “Ockham’s  Razor  and  the  Topology  of  Statistical  Inquiry”,  Lingnan University, Hong Kong, Summer 2016.
  • (With Konstantin Genin) “Deduction, Induction, and Statistical Inference”, Philosophy of Scientific Experimentation 5, University of Belgrade, Fall 2016.
  • (With Konstantin Genin) “A Topological Explanation of Empirical Simplicity”, Philosophy of Sci- ence Biennial Meeting, Atlanta, Fall 2016.
  • (With Konstantin Genin) “The Topology of Statistical Verifiability”, TARK 2017, Birmingham.
  • "An Erotetic Theory of Empirical Simplicity and its Connection with Truth", Beth/Vienna Circle Lecture: University of Amsterdam, Winter 2011.
  • "Science: the Topology of Inquiry". Two day tutorial. Culture Matters Lecture Series, The University of Lausanne, Fondation Suisse d'Etudes, Winter 2011.
  • "An Erotetic Theory of Simplicity and its Connection with Truth". Department of Philosophy, University of Geneva, Winter 2011.
  • "Simplicity and its Connection with Empirical Truth", Workshop on Explanation, Causality, and Explanation", Heinrich Heine University, Duesseldorf.
  • (with Hanti Lin) "A Happy Marriage Between Propositional and Probabilistic Reasoning", Workshop on Explanation, Causation, and Unification, Heinrich Heine University, Duesseldorf, Autumn, 2011.
  • "A Topological Theory of Simplicity and its Connection with Truth", PhilMath Intersem 2011, Simplicity/Complexity of Proof, Sorbonne, Paris, Summer 2011.
  • (with Hanti Lin) "Propositional Reasoning that Tracks Probabilistic Reasoning", Department of Philosophy, University of Kyoto, Summer 2011.
  • "Simplicity, Truth, Zen", Department of Philsosophy, University of Kyoto, Summer 2011.
  • (with Hanti Lin) "Propositional Reasoning that Tracks Probabilistic Reasoning", Formal Epistemology Workshop, University of Southern California, Los Angeles, Summer 2011.
  • "Inductive Knowledge: A Learning Theoretic Semantics for Modal Epistemic Logic", CSLI, Spring 2011.
  • (with Hanti Lin) "Propositional Reasoning that Tracks Probabilistic Reasoning", Workwhop on Acceptance, CFE, Carnegie Mellon, Spring 2011.
  • (with Hanti Lin),"Belief Revision, Ockham's Razor, and Truth-Conduciveness'', A Tribute to Horacio Arlo-Costa, Sociedad Argentina De Analysis Filisofico, Summer 2012.
  • (with Hanti Lin),"Ockham's Razor and Truth'', Workshop on the Foundations of Ockham's Razor, Center for Formal Epistemology, Carnegie Mellon University, Summer 2012.
  • "The Topology of Inquiry'', Carnegie Mellon Summer School, Summer, 2012.
  • (with Hanti Lin) "A Logical Explanation of Ockham's Razor in Theory Choice'', First CSLI Workshop on Logic, Rationality, and Interaction, Stanford, Summer 2012.
  • (with Hanti Lin) "Ockham's Razors'', CADILLAC, University of Copenhagen, Spring 2012.
  • "Learning Theoretic Models for Modal Epistemic Logic'', Games, Interactive Rationality and Learning Workshop, Lund, Spring 2012.
  • "A Happy Marriage Between Propositional and Probabilistic Reasoning'', Filosofiskafoereningen, Lund, Spring 2012.
  • "Tutorial on Ockham's Razor'', Center for Mathematical Philosophy, LMU, Munich, Spring 2012.
  • (with Hanti Lin) "Doxastic Engineering'', Roundtable on Acceptance, Center for Mathematical Philosophy, LMU, 2012.
  • "An Erotetic Theory of Simplicity and its Relation to Truth'', Interrogative Models of Inquiry Workshop, Sorbonne, Paris, Spring 2012.
  • "Simplicity, Truth, and Ockham's Razor'', Center for Mathematical Philosophy, LMU, Munich, Spring 2012.
  • "The Bayesian Miracle'', Workshop on Radical Uncertainty, Center for Mathematical Philosophy, LMU, Munich, Spring 2012.
  • "Topological Epistemology'', Logic and Interactive Rationality three day seminar, ILLC, Amsterdam, Spring 2012.
  • (with Hanti Lin) "Uncertain Acceptance and Contextual Dependence on Questions'', LogicCiC Seminar Series, ILLC, University of Amsterdam, Spring 2012.
  • (with Hanti Lin) "Propositional Reasoning that Tracks Probabilistic Reasoning'', LogicCiC Seminar Series, ILLC, University of Amsterdam, Spring 2012.
  • (with Hanti Lin) "Propositional Reasoning that Tracks Probabilistic Reasoning'', University of Groeningen, Spring 2012.
  • "Simplicity, Truth, and Ockham's Razor'', Universityof Groeningen, Spring 2012.
  • "Knowability, Inquiry, and Epistemic Logic'', University of Kyoto, Japan, Winter 2013.
  • "A Computational Learning Semantics for Inductive Common Knowledge'', Sendai University, Japan, Winter 2013.
  • "A Multi-Agent Learning Semantics for Inductive Common Knowledge'' , Workshop on Social Dynamics of Information Change, University of Amsterdam, Autumn 2013.
  • (with Hanti Lin) "Qualitative Reasoning that Tracks Jeffrey Conditioning'', Progic, Luwig-Maximiliens University, Munich, Autumn 2013.
  • "The Topology of Inquiry'', CMU Summer School, Carnegie Mellon University, Summer 2013.
  • (with Hanti Lin) "Empirical Simplicity, Efficient Inquiry, and Ockham's Razor'', CFE workshop on the Logic of Simplicity, Carnegie Mellon University, Summer 2013.
  • "Propositional Reasoning that Tracks Probabilistic Reasoning'', Institute for History and Philosophy of Science and Technology, Sorbonne, Paris, Summer 2013.
  • "Ockham's Razor as Belief Revision''. Logic, Questions, and Inquiry", Institute for History and Philosophy of Science and Technology, Sorbonne, Paris, Summer 2013.
  • "Simplicity, Truth, and Ockham's Razor'', Conference on Modes of Explanation, American University, Paris, Summer 2013.
  • "A Learning Semantics for Inductive Knowledge'', Modal Logic Workshop, University of Roskilde, Denmark, Spring 2013.
  • "A Hyper-intensional Learning Semantics for Inductive Knowledge'', Workshop for Games, Interaction, Rationality, and Learning, University of Lund, Sweden, Spring 2013.

  • "Causal Conclusions that Flip Repeatedly and Their Justification'', Plenary Talk, 26th Conference on Uncertainty in Artificial Intelligence, Catalina island, Summer 2010.

  • "Simplicity and Truth'', Workshop on the Nature of Laws, Perimeter Institute for Theoretical Physics, Summer 2010.

  • "Simplicity, Truth, and Zen'', Keynote, Graduate Conference, University of Western Ontario, Summer 2010.

  • "Ockham's Razor, Without Circles, Evasions, or Magic'', Institute for the History and Philosophy of Science and Technology (IHPST), University of Paris, Summer 2008.

  • "Relations of Ideas are Matters of Fact: A Unified Theory of Theoretical Unification", Ideals of Proof Workshop, University of Nancy, France, Summer 2008.

  • "Relations of Ideas are Matters of Fact: Justification as Truth-finding Performance'', Lecture, Conference on Science and Methods, Visva Bharati University, Santiniketan, India, Spring 2008.

  • "Unity of Science Without Dogma'', Keynote Lecture, Conference on Science and Methods, Asiatic Society, Kolkata, India, Spring 2008.

  • "Simplicity, Truth, and Causation: A New Explanation of Ockham's Razor'', Indian Statistical Instituite, Platinum Anniversary Lecture on Causation, Kolkata, India, Spring 2008.

  • "Ockham's Razor in Causal Discovery: A New Explanation'', Lecture, National Institute of Science, Technology, and Development Studies, University of Delhi, New Delhi, India, Spring 2008.

  • "Simplicity and Truth'', Lecture, Department of Philosophy, University of Jaipur, Jaipur, India, Fall 2007.

  • "Simplicity and Truth: an Alternative Explanation of Ockham's Razor'', Keynote address, 8th International Conference on Intelligent Data Engineering and Automated Learning (IDEAL'07), Birmingham, UK, Fall 2007.

  • "Truth-conduciveness Without Reliability: A Non-Theological Explanation of Ockham's Razor'', Lecture, Working Group in Science, Technology, and Society, University of California,Berkeley, Fall 2007.

  • "Ockham's Razor Without Circles, Evasions, or Magic'', Formal Epistemology Workshop, Pittsburgh, Summer 2007.

  • "Ockham's Razor'', Philosophy of Science association biennial meeting, Vancouver, Fall, 2006.

  • "Philosophical Logic and Reliability'', Philosophical Logic Symposium for Johan van Benthem, Carnegie Mellon, Spring, 2006.

  • "Ockham's Razor'', invited lecture, Department of Philosophy, Stanford, Spring, 2006.

  • "Belief Revision and Truth Finding.'', Second Annual Formal Epistemology Workshop, University of Texas, Austin, Summer 2005.

  • "Ockham's Razor: What it is, what it isn't, how it works, and how it doesn't'', Second Annual Formal Epistemology Workshop, University of Texas, Austin, Summer 2005.

  • "Church's Thesis and Hume's Problem: Justification as Performance'', Second Annual Formal Epistemology Workshop, University of Texas, Austin, Summer 2005.

  • "Ockham's Razor: What it is, What it isn't, How it Works and How it Doesn't.''Symposium on Logic in the Humanities, Stanford University, Spring 2005.

  • "Ockham, Complexity, and Truth'', Western Division Meeting of the American Mathematical Society, Santa Barbara, Spring 2005.

  • "Learning, Simplicity, Truth, and Misinformation'', First International Workshop on the Philosophy of Information, Amsterdam, Netherlands, Spring 2005.

  • "Ockham's Razor, Efficiency, and the Infinite Game of Science'', invited Plenary Lecture, Foundations of the Formal Sciences 2004: Infinite Game Theory, Bonn, Germany, Fall 2004.

  • "How Ockham's Razor Helps You Find the Truth'', U.C. Irvine, Spring 2004.

  • "Ockham's Razor'', Center for Philosophy of Science, Fall 2004.

  • "Convergent Computation and Hyper-computation'', Special Session on Hyper-computability, American Mathematical Society meeting, California State University at San Francisco, May 2003.

  • "Efficient Convergence Implies Ockham's Razor'', International Workshop on Computational Models of Scientific Reasoning and Applications, Las Vegas, USA, June 24-27, 2002.

  • "Simplicity Deduced from Efficient Convergence'', 40th Anniversary Conference, Center for Philosophy of Science, University of Pittsburgh, 2001.

  • "How to Do Things with an Infinite Regress'', Annual Lecture Series, Center for Philosophy of Science, University of Pittsburgh, Spring 2000.

  • "How to Do Things with an Infinite Regress'', Philosophy of Science Biennial meeting, Vancouver, 2000.

  • "Reliable vs. Coherent Belief Revision'', Logic Colloquium, University of Indiana, Spring 1999.

  • "Learning theory and the Philosophy of Science'' Logic Colloquium, University of Indiana, Spring 1999.

  • "The Learning Power of Belief Revision'', 7th Conference on Theoretical Aspects of Rationality and Knowledge (TARK), Kellogg School of Economics, Evanston IL, 1998.

  • "A Learning Theoretic Analysis of Spohn's Iterated Belief Revision Model'', Center for Philosophy of Science, University of Pittsburgh, 1998.

  • "Church Meets Hume'', Philosophy Department, University of Missouri, St. Louis, Spring 1996.

  • "Church's Thesis and Hume's Problem'', 10th International Union of History and Philosophy of Science, Florence, Summer 1995.

  • "Logical Methods vs. Logical Methodology'', 10th International Union of History and Philosophy of Science, Florence, Summer 1995.

  • "Relativistic Computer Modeling'', Conference on the Limits of Computer Modelling, Schloss Dagstuhl, West Germany, Spring 1992.

  • "Probability, Learning Theory, and Induction'', Summer School, Erasmus Program in Logic, History, and Philosophy of Science, Aarhus, Denmark, Summer 1992.

  • "Underdetermination, Probability and Uncomputability'', McDonnell Foundation Conference on Methodological Issues in Cognitive Science, Summer 1992.

  • "So Much Time; Such Little Brains'', Center for Philosophy of Science, University of Pittsburgh, Spring, 1991.

  • "Relativism and Inquiry'', Department of English, Carnegie Mellon University, Spring 1991.

  • "The Empirical Paradox of Cognitive Science'', 9th International Conference of Logic, Methodology and Philosophy of Science, Summer, 1991.

  • "From Trial and Error Predicates to Internal Realism and Back again''. Gifford International Conference, St. Andrews, Scotland, Autumn, 1990.

  • "Getting to the Truth through Conceptual Revolutions'', PSA Biennial Meeting, Autumn 1990.

  • "A Survey of Results in the Theory of Inductive Inference'', Department of Mathematics, Roskilde University Center, Denmark, Spring 1989.

  • "Theory Discovery from Quantified Data'', Datalogic Institute, University of Copenhagen, Denmark, Spring 1989.

  • "A Formal Critique of Karl Popper's Philosophy'', Department of Philosophy, University of Copenhagen, Denmark, Summer 1989.

  • "Relativistic Inductive Inference'', Department of Philosophy, University of Aalborg, Denmark, Summer 1989.

  • "Convergent Relativism'', University of Konstanz, West Germany, Summer 1989.

  • "Inductive Convergence Time and the Vapnik-Chervonenkis Dimension'', Informatics Department, Risoe National Laboratory, Denmark, Summer 1989.

  • "Computational Approaches to Inductive Inference'', The Fourth International Conference on Computers and Philosophy, CDEC, Carnegie Mellon University, Autumn 1989.

  • "Getting to the Truth when the Truth Depends on You'', Graduate School for Industrial Administration, Carnegie Mellon University, Autumn, 1989.

  • "Formal Learning Theory and the Philosophy of Science'', Philosophy of Science Association, Chicago, IL, Autumn 1988.