Modal scope fallacy
In this article, we will address the topic of Modal scope fallacy from a broad and multidisciplinary perspective. Modal scope fallacy is a topic of great relevance today, which has captured the attention of specialists and the general public. Throughout history, Modal scope fallacy has played a fundamental role in various aspects of society, culture and everyday life. Through this article, we will explore the various approaches, debates and perspectives that revolve around Modal scope fallacy, with the aim of offering a comprehensive and enriching vision on this topic.
 | This article includes a list of general references, but it lacks sufficient corresponding inline citations. (October 2019) |
A fallacy of necessity is a fallacy in the logic of a syllogism whereby a degree of unwarranted necessity is placed in the conclusion.
Example
- a) Bachelors are necessarily unmarried.
- b) John is a bachelor.
- Therefore, c) John cannot marry.
The condition a) appears to be a tautology and therefore true. The condition b) is a statement of fact about John which makes him subject to a); that is, b) declares John a bachelor, and a) states that all bachelors are unmarried.
Because c) presumes b) will always be the case, it is a fallacy of necessity. John, of course, is always free to stop being a bachelor, simply by getting married; if he does so, b) is no longer true and thus not subject to the tautology a). In this case, c) has unwarranted necessity by assuming, incorrectly, that John cannot stop being a bachelor. Formally speaking, this type of argument equivocates between the de dicto necessity of a) and the de re necessity of c). The argument is only valid if both a) and c) are construed de re. This, however, would undermine the argument, as a) is only a tautology de dicto – indeed, interpreted de re, it is false. Using the formal symbolism in modal logic, the de dicto expression is a tautology, while the de re expression is false.
See also
References
- ^ Garson, James (2021), Zalta, Edward N. (ed.), "Modal Logic", The Stanford Encyclopedia of Philosophy (Summer 2021 ed.), Metaphysics Research Lab, Stanford University, retrieved 2022-03-02
- Curtis, Gary N., "Modal Scope Fallacy", The Fallacy Files, retrieved 22 October 2014
- Bradley, Raymond; Swartz, Norman (1979), "Problems with the use of "it is necessary that"; the modal fallacy; absolute and relative necessity", Possible Worlds: An Introduction to Logic and Its Philosophy, Hackett Publishing Company, pp. 330–332, ISBN 978-0-915144-60-0
- Swartz, Norman, More on "The" Modal Fallacy, retrieved 22 October 2014
- Franzén, Torkel, Eternal Questions: Free Will and Divine Omniscience, archived from the original on 2007-07-08, retrieved 22 October 2014
| Formal |
| ||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Informal |
| ||||||||||||||||||||||||||||||||||
