, Volume 184, Issue 1, pp 109–114 | Cite as

Quantum probabilities and the conjunction principle



A recent argument by Hawthorne and Lasonen-Aarnio purports to show that we can uphold the principle that competently forming conjunctions is a knowledge-preserving operation only at the cost of a rampant skepticism about the future. A key premise of their argument is that, in light of quantum-mechanical considerations, future contingents never quite have chance 1 of being true. We argue, by drawing attention to the order of magnitude of the relevant quantum probabilities, that the skeptical threat of Hawthorne and Lasonen-Aarnio’s argument is illusory.


Quantum probabilities Conjunction principle Skepticism 


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Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  1. 1.Institute of PhilosophyUniversity of LeuvenLeuvenBelgium
  2. 2.Institute for History and Foundations of ScienceUtrecht UniversityUtrechtThe Netherlands

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