University Of Erfurt
Department Of Philosophy
Toronto, Ontario, Canada
  •  731
    Ranking Theory
    In Richard Pettigrew & Jonathan Weisberg (eds.), The Open Handbook of Formal Epistemology, Philpapers Foundation. pp. 397-436. 2019.
  •  5
    A Logical Introduction to Probability and Induction starts with elementary logic and uses it as basis for a philosophical discussion of probability and induction. Throughout the book results are carefully proved using the inference rules introduced at the beginning. The textbook is suitable for undergraduate courses in philosophy and logic.
  •  448
    On the justification of deduction and induction
    European Journal for Philosophy of Science 7 (3): 507-534. 2017.
    The thesis of this paper is that we can justify induction deductively relative to one end, and deduction inductively relative to a different end. I will begin by presenting a contemporary variant of Hume ’s argument for the thesis that we cannot justify the principle of induction. Then I will criticize the responses the resulting problem of induction has received by Carnap and Goodman, as well as praise Reichenbach ’s approach. Some of these authors compare induction to deduction. Haack compares…Read more
  •  292
    Bayesian Confirmation: A Means with No End
    British Journal for the Philosophy of Science 66 (4): 737-749. 2015.
    Any theory of confirmation must answer the following question: what is the purpose of its conception of confirmation for scientific inquiry? In this article, we argue that no Bayesian conception of confirmation can be used for its primary intended purpose, which we take to be making a claim about how worthy of belief various hypotheses are. Then we consider a different use to which Bayesian confirmation might be put, namely, determining the epistemic value of experimental outcomes, and thus to d…Read more
  •  42
    Kroedel has proposed a new solution, the permissibility solution, to the lottery paradox. The lottery paradox results from the Lockean thesis according to which one ought to believe a proposition just in case one’s degree of belief in it is sufficiently high. The permissibility solution replaces the Lockean thesis by the permissibility thesis according to which one is permitted to believe a proposition if one’s degree of belief in it is sufficiently high. This note shows that the epistemology of…Read more
  •  220
    The paper presents a new analysis of Hempel’s conditions of adequacy, differing from the one in Carnap. Hempel, so it is argued, felt the need for two concepts of confirmation: one aiming at true theories, and another aiming at informative theories. However, so the analysis continues, he also realized that these two concepts were conflicting, and so he gave up the concept of confirmation aiming at informative theories. It is then shown that one can have the cake and eat it: There is a logic of c…Read more
  •  131
    Belief First
    The Reasoner 7 (7): 82. 2013.
  •  236
    Ranking Functions
    In A. Pazos Sierra, J. R. Rabunal Dopico & J. Dorado de la Calle (eds.), Encyclopedia of Artificial Intelligence, Hershey. 2009.
    Ranking functions have been introduced under the name of ordinal conditional functions in Spohn (1988; 1990). They are representations of epistemic states and their dynamics. The most comprehensive and up to date presentation is Spohn (manuscript).
  •  127
    For True Conditionalizers Weisberg’s Paradox is a False Alarm
    Symposion: Theoretical and Applied Inquiries in Philosophy and Social Sciences 1 (1): 111-119. 2014.
    Weisberg introduces a phenomenon he terms perceptual undermining. He argues that it poses a problem for Jeffrey conditionalization, and Bayesian epistemology in general. This is Weisberg’s paradox. Weisberg argues that perceptual undermining also poses a problem for ranking theory and for Dempster-Shafer theory. In this note I argue that perceptual undermining does not pose a problem for any of these theories: for true conditionalizers Weisberg’s paradox is a false alarm.
  •  524
    Belief and Degrees of Belief
    In F. Huber & C. Schmidt-Petri (eds.), Degrees of Belief, Springer. 2009.
    Degrees of belief are familiar to all of us. Our confidence in the truth of some propositions is higher than our confidence in the truth of other propositions. We are pretty confident that our computers will boot when we push their power button, but we are much more confident that the sun will rise tomorrow. Degrees of belief formally represent the strength with which we believe the truth of various propositions. The higher an agent’s degree of belief for a particular proposition, the higher her con…Read more
  •  15
    Vincent F. Hendricks, Mainstream and Formal Epistemology (review)
    Philosophy in Review 26 257-259. 2006.
  •  155
    Inductive Logic
    In J. Lachs R. Talisse (ed.), Encyclopedia of American Philosophy, Routledge. 2008.
    Logic is the study of the quality of arguments. An argument consists of a set of premises and a conclusion. The quality of an argument depends on at least two factors: the truth of the premises, and the strength with which the premises confirm the conclusion. The truth of the premises is a contingent factor that depends on the state of the world. The strength with which the premises confirm the conclusion is supposed to be independent of the state of the world. Logic is only concerned with this …Read more
  •  278
    The Consistency Argument for Ranking Functions
    Studia Logica 86 (2): 299-329. 2007.
    The paper provides an argument for the thesis that an agent’s degrees of disbelief should obey the ranking calculus. This Consistency Argument is based on the Consistency Theorem. The latter says that an agent’s belief set is and will always be consistent and deductively closed iff her degrees of entrenchment satisfy the ranking axioms and are updated according to the ranktheoretic update rules.
  •  210
    Milne’s Argument for the Log‐Ratio Measure
    Philosophy of Science 75 (4): 413-420. 2008.
    This article shows that a slight variation of the argument in Milne 1996 yields the log‐likelihood ratio l rather than the log‐ratio measure r as “the one true measure of confirmation. ” *Received December 2006; revised December 2007. †To contact the author, please write to: Formal Epistemology Research Group, Zukunftskolleg and Department of Philosophy, University of Konstanz, P.O. Box X906, 78457 Konstanz, Germany; e‐mail: [email protected]‐
  •  445
    Evidential Support and Instrumental Rationality
    with Peter Brössel and Anna-Maria A. Eder
    Philosophy and Phenomenological Research 87 (2): 279-300. 2013.
  •  227
    What Should I Believe About What Would Have Been the Case?
    Journal of Philosophical Logic 44 (1): 81-110. 2015.
    The question I am addressing in this paper is the following: how is it possible to empirically test, or confirm, counterfactuals? After motivating this question in Section 1, I will look at two approaches to counterfactuals, and at how counterfactuals can be empirically tested, or confirmed, if at all, on these accounts in Section 2. I will then digress into the philosophy of probability in Section 3. The reason for this digression is that I want to use the way observable absolute and relative f…Read more
  •  166
    The plausibility-informativeness theory
    In Vincent Hendricks (ed.), New Waves in Epistemology, Palgrave-macmillan. 2008.
    The problem adressed in this paper is “the main epistemic problem concerning science”, viz. “the explication of how we compare and evaluate theories [...] in the light of the available evidence” (van Fraassen 1983, 27).
  •  438
    Belief Revision I: The AGM Theory
    Philosophy Compass 8 (7): 604-612. 2013.
    Belief revision theory studies how an ideal doxastic agent should revise her beliefs when she receives new information. In part I I will first present the AGM theory of belief revision (Alchourrón & Gärdenfors & Makinson 1985). Then I will focus on the problem of iterated belief revisions
  •  304
    Ranking Functions and Rankings on Languages
    Artificial Intelligence 170 (4-5): 462-471. 2006.
    The Spohnian paradigm of ranking functions is in many respects like an order-of-magnitude reverse of subjective probability theory. Unlike probabilities, however, ranking functions are only indirectly—via a pointwise ranking function on the underlying set of possibilities W —defined on a field of propositions A over W. This research note shows under which conditions ranking functions on a field of propositions A over W and rankings on a language L are induced by pointwise ranking functions on W …Read more
  •  302
    Hempel’s logic of confirmation
    Philosophical Studies 139 (2): 181-189. 2008.
    This paper presents a new analysis of C.G. Hempel’s conditions of adequacy for any relation of confirmation [Hempel C. G. (1945). Aspects of scientific explanation and other essays in the philosophy of science. New York: The Free Press, pp. 3–51.], differing from the one Carnap gave in §87 of his [1962. Logical foundations of probability (2nd ed.). Chicago: University of Chicago Press.]. Hempel, it is argued, felt the need for two concepts of confirmation: one aiming at true hypotheses and anoth…Read more
  •  49
    Why follow the royal rule?
    Synthese 194 (5). 2017.
    This note is a sequel to Huber. It is shown that obeying a normative principle relating counterfactual conditionals and conditional beliefs, viz. the royal rule, is a necessary and sufficient means to attaining a cognitive end that relates true beliefs in purely factual, non-modal propositions and true beliefs in purely modal propositions. Along the way I will sketch my idealism about alethic or metaphysical modality.
  •  335
    Structural equations and beyond
    Review of Symbolic Logic 6 (4): 709-732. 2013.
    Recent accounts of actual causation are stated in terms of extended causal models. These extended causal models contain two elements representing two seemingly distinct modalities. The first element are structural equations which represent the or mechanisms of the model, just as ordinary causal models do. The second element are ranking functions which represent normality or typicality. The aim of this paper is to show that these two modalities can be unified. I do so by formulating two constrain…Read more
  •  218
    The Logic of Theory Assessment
    Journal of Philosophical Logic 36 (5): 511-538. 2007.
    This paper starts by indicating the analysis of Hempel's conditions of adequacy for any relation of confirmation (Hempel, 1945) as presented in Huber (submitted). There I argue contra Carnap (1962, Section 87) that Hempel felt the need for two concepts of confirmation: one aiming at plausible theories and another aiming at informative theories. However, he also realized that these two concepts are conflicting, and he gave up the concept of confirmation aiming at informative theories. The main pa…Read more
  •  11
    Neuroethology, according to Hoyle
    Behavioral and Brain Sciences 7 (3): 391-392. 1984.
  •  158
    Essay Review: The Laws of Belief (review)
    Philosophy of Science 79 (4): 584-588. 2012.
  •  266
    Wolfgang Spohn: The laws of belief (review)
    Philosophy of Science 79 (4): 584-588. 2012.