, Volume 30, Issue 1, pp 3–15

Triviality Pursuit


DOI: 10.1007/s11245-010-9083-2

Cite this article as:
Hájek, A. Topoi (2011) 30: 3. doi:10.1007/s11245-010-9083-2


The thesis that probabilities of conditionals are conditional probabilities has putatively been refuted many times by so-called ‘triviality results’, although it has also enjoyed a number of resurrections. In this paper I assault it yet again with a new such result. I begin by motivating the thesis and discussing some of the philosophical ramifications of its fluctuating fortunes. I will canvas various reasons, old and new, why the thesis seems plausible, and why we should care about its fate. I will look at some objections to Lewis’s famous triviality results, and thus some reasons for the pursuit of further triviality results. I will generalize Lewis’s results in ways that meet the objections. I will conclude with some reflections on the demise of the thesis—or otherwise.


Probabilities of conditionalsConditional probabilitiesStalnaker’s thesisTriviality resultsConditionalizationImagingBlurred imagingMaximum entropyMinimum cross entropyBoldnessModerationRevision rules

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  1. 1.Research School of Social SciencesAustralian National UniversityCanberraAustralia