Avoiding omnidoxasticity in logics of belief: A reply to MacPherson.

SelectedWorks Author Profiles:

Han Reichgelt

Document Type


Publication Date


Date Issued

January 1995

Date Available

July 2014




In recent work MacPherson argues that the standard method of modeling belief logically, as a necessity operator in a modal logic, is doomed to fail. The problem with normal modal logics as logics of belief is that they treat believers as “ideal” in unrealistic ways (i.e., as omnidoxastic); however, similar problems re-emerge for candidate non-normal logics. The authors argue that logics used to model belief in artificial intelligence (AI) are also flawed in this way. But for AI systems, omnidoxasticity is impossible because of their finite nature, and this fact can be exploited to produce operational models of fallible belief. The relevance of this point to various philosophical views about belief is discussed.


Citation only. Full-text article is available through licensed access provided by the publisher. Published in Notre Dame Journal of Formal Logic, 36, 475-495. doi:10.1305/ndjfl/1040149361. Members of the USF System may access the full-text of the article through the authenticated link provided.




Duke University Press

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Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.