266 research outputs found
On Empirical Equivalence and Duality
I argue that, on a judicious reading of two existing criteria--one syntactic
and the other semantic--dual theories can be taken to be empirically
equivalent. The judicious reading is straightforward, but leads to the
surprising conclusion that very different-looking theories can have equivalent
empirical content. And thus it shows how a widespread scientific practice, of
interpreting duals as empirically equivalent, can be understood by a thus-far
unnoticed feature of existing accounts of empirical equivalence
Intentionality versus Constructive Empiricism
By focussing on the intentional character of observation in science, we argue that Constructive Empiricism â B.C. van Fraassenâs much debated and explored view of science â is inconsistent. We then argue there are at least two ways out of our Inconsistency Argument, one of which is more easily to square with Constructive Empiricism than the other
On Empirical Equivalence and Duality
I argue that, on a judicious reading of two existing criteria--one syntactic and the other semantic--dual theories can be taken to be empirically equivalent. The judicious reading is straightforward, but leads to the surprising conclusion that very different-looking theories can have equivalent empirical content. And thus it shows how a widespread scientific practice, of interpreting duals as empirically equivalent, can be understood by a thus-far unnoticed feature of existing accounts of empirical equivalence
Bayesian Conditioning, the Reflection Principle, and Quantum Decoherence
The probabilities a Bayesian agent assigns to a set of events typically
change with time, for instance when the agent updates them in the light of new
data. In this paper we address the question of how an agent's probabilities at
different times are constrained by Dutch-book coherence. We review and attempt
to clarify the argument that, although an agent is not forced by coherence to
use the usual Bayesian conditioning rule to update his probabilities, coherence
does require the agent's probabilities to satisfy van Fraassen's [1984]
reflection principle (which entails a related constraint pointed out by
Goldstein [1983]). We then exhibit the specialized assumption needed to recover
Bayesian conditioning from an analogous reflection-style consideration.
Bringing the argument to the context of quantum measurement theory, we show
that "quantum decoherence" can be understood in purely personalist
terms---quantum decoherence (as supposed in a von Neumann chain) is not a
physical process at all, but an application of the reflection principle. From
this point of view, the decoherence theory of Zeh, Zurek, and others as a story
of quantum measurement has the plot turned exactly backward.Comment: 14 pages, written in memory of Itamar Pitowsk
Refutations of the Two Pessimistic Inductions
Both the pessimistic inductions over scientific theories and over scientists are built upon what I call proportional pessimism: as theories are discarded, the inductive rationale for concluding that the next theories will be discarded grows stronger. I argue that proportional pessimism clashes with the fact that present theories are more successful than past theories, and with the implications of the assumptions that there are finitely and infinitely many unconceived alternatives. Therefore, the two pessimistic inductions collapse along with proportional pessimism
On Semantic Gamification
The purpose of this essay is to study the extent in which the semantics for different logical systems can be represented game theoretically. I will begin by considering different definitions of what it means to gamify a semantics, and show completeness and limitative results. In particular, I will argue that under a proper definition of gamification, all finitely algebraizable logics can be gamified, as well as some infinitely algebraizable ones (like Ćukasiewicz) and some non-algebraizable (like intuitionistic and van Fraassen supervaluation logic)
Vagueness and Imprecise Credence
In this paper I investigate an alternative to imprecise probabilism. Imprecise probabilism is a popular revision of orthodox Bayesianism: while the orthodox Bayesian claims that a rational agentâs belief-state can be represented by a single credence function, the imprecise probabilist claims instead that a rational agentâs belief-state can be represented by a set of such functions. The alternative that I put forward in this paper is to claim that the expression âcredenceâ is vague, and then apply the theory of supervaluationism to sentences containing this expression. This gives us a viable alternative to imprecise probabilism, and I end by comparing the two accounts. I show that supervaluationism has a simpler way of handling sentences relating the belief-states of two different people, or of the same person at two different times; that both accounts may have the resources to develop plausible decision theories; and finally that the supervaluationist can accommodate higher-order vagueness in a way that is not available to the imprecise probabilist
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