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
  •  172
    The Logic of Confirmation and Theory Assessment
    In L. Behounek & M. Bilkova (eds.), The Logica Yearbook, Filosofia. 2005.
    This paper discusses an almost sixty year old problem in the philosophy of science -- that of a logic of confirmation. We present a new analysis of Carl G. Hempel's conditions of adequacy (Hempel 1945), differing from the one Carnap gave in §87 of his Logical Foundations of Probability (1962). Hempel, it is argued, felt the need for two concepts of confirmation: one aiming at true theories and another aiming at informative theories. However, he also realized that these two concepts are conflicti…Read more
  •  296
    New foundations for counterfactuals
    Synthese 191 (10): 2167-2193. 2014.
    Philosophers typically rely on intuitions when providing a semantics for counterfactual conditionals. However, intuitions regarding counterfactual conditionals are notoriously shaky. The aim of this paper is to provide a principled account of the semantics of counterfactual conditionals. This principled account is provided by what I dub the Royal Rule, a deterministic analogue of the Principal Principle relating chance and credence. The Royal Rule says that an ideal doxastic agent’s initial grad…Read more
  •  84
    Formal Representations of Belief
    Stanford Encyclopedia of Philosophy. 2008.
    Epistemology is the study of knowledge and justified belief. Belief is thus central to epistemology. It comes in a qualitative form, as when Sophia believes that Vienna is the capital of Austria, and a quantitative form, as when Sophia's degree of belief that Vienna is the capital of Austria is at least twice her degree of belief that tomorrow it will be sunny in Vienna. Formal epistemology, as opposed to mainstream epistemology (Hendricks 2006), is epistemology done in a formal way, that is, by…Read more
  •  591
    Counterfactual Dependence and Arrow
    Noûs 47 (3): 453-466. 2013.
    We argue that a semantics for counterfactual conditionals in terms of comparative overall similarity faces a formal limitation due to Arrow’s impossibility theorem from social choice theory. According to Lewis’s account, the truth-conditions for counterfactual conditionals are given in terms of the comparative overall similarity between possible worlds, which is in turn determined by various aspects of similarity between possible worlds. We argue that a function from aspects of similarity to ove…Read more
  •  269
    Assessing theories, Bayes style
    Synthese 161 (1): 89-118. 2008.
    The problem addressed 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, BC, 1983, Theory comparison and relevant Evidence. In J. Earman (Ed.), Testing scientific theories (pp. 27–42). Minneapolis: University of Minnesota Press). Sections 1– 3 contain the general plausibility-informativeness theory of theory assessment. In a nutshell, the message is (1) that t…Read more
  •  80
    Vincent F. Hendricks, Mainstream and Formal Epistemology Reviewed by (review)
    Philosophy in Review 26 (4): 257-259. 2006.
  •  365
    Oxford Bibliographies Online. 2011.
  •  348
    Subjective Probabilities as Basis for Scientific Reasoning?
    British Journal for the Philosophy of Science 56 (1): 101-116. 2005.
    Bayesianism is the position that scientific reasoning is probabilistic and that probabilities are adequately interpreted as an agent's actual subjective degrees of belief, measured by her betting behaviour. Confirmation is one important aspect of scientific reasoning. The thesis of this paper is the following: if scientific reasoning is at all probabilistic, the subjective interpretation has to be given up in order to get right confirmation—and thus scientific reasoning in general. The Bayesian …Read more
  •  179
    Lewis Causation is a Special Case of Spohn Causation
    British Journal for the Philosophy of Science 62 (1): 207-210. 2011.
    This paper shows that causation in the sense of Lewis is a special case of causation in the sense of Spohn.
  •  130
    Degrees of Belief (edited book)
    Springer. 2008.
    Various theories try to give accounts of how measures of this confidence do or ought to behave, both as far as the internal mental consistency of the agent as ...
  •  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
  •  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
  •  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]‐
  •  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
  •  445
    Evidential Support and Instrumental Rationality
    with Peter Brössel and Anna-Maria A. Eder
    Philosophy and Phenomenological Research 87 (2): 279-300. 2013.
  •  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