View source for Plato's beard

{{short description|Example of a paradoxical argument}}
In [[Philosophy:Metaphysics|metaphysics]], '''Plato's beard''' is a [[Philosophy:Paradox|paradox]]ical argument dubbed by [[Biography:Willard Van Orman Quine|Willard Van Orman Quine]] in his 1948 paper "On What There Is". The phrase came to be identified as the philosophy of understanding something based on what does not exist.<ref>{{Cite book|title=American Phoenix: John Quincy and Louisa Adams, the War of 1812, and the Exile that Saved American Independence|last=Cook|first=Jane|publisher=Thomas Nelson|year=2013|isbn=9781595555410|location=Nashville|pages=[https://archive.org/details/americanphoenixj0000cook/page/186 186]|url=https://archive.org/details/americanphoenixj0000cook/page/186}}</ref>

== Doctrine ==
Quine defined [[Biography:Plato|Plato]]'s beard – and his reason for naming it so – in the following words:
<blockquote>
This is the old [[Philosophy:Platonic idealism|Platonic]] riddle of nonbeing. Nonbeing must in some sense be, otherwise what is it that there is not? This tangled [[Philosophy:Doctrine|doctrine]] might be nicknamed Plato's beard; historically it has proved tough, frequently dulling the edge of [[Occam's razor]].<ref>W. V. O. Quine, "On What There Is", ''The Review of Metaphysics'' '''2'''(5), 1948.</ref>
</blockquote>

The argument has been favored by prominent philosophers including [[Biography:Bertrand Russell|Bertrand Russell]], [[Biography:A. J. Ayer|A. J. Ayer]] and [[Biography:C. J. F. Williams|C. J. F. Williams]].<ref name="Vallicella2002">{{cite book |last=Vallicella |first=William F. |url=https://books.google.com/books?id=39-nB4lHdf0C&pg=PA112 |title=A Paradigm Theory of Existence: Onto-Theology Vindicated |publisher=Springer |year=2002 |isbn=978-1-4020-0887-0 |page=112}}</ref> Declaring that not ''p'' (¬''p'') cannot exist, one may be forced to abandon [[Philosophy:Truism|truism]]s such as [[Negation|negation]] and ''[[Modus tollens|modus tollens]]''. There are also variations to Quine's original, which included its application both to singular and general terms.<ref name=":0">{{Cite book|title=Mental Symbols: A Defence of the Classical Theory of Mind|last=Novak|first=Peter|publisher=Springer Science+Business Media B.V.|year=2012|isbn=9789401063746|location=New York|page=40}}</ref> Quine initially applied the doctrine to singular terms only before expanding it so that it covers general terms as well.<ref name=":0" />

[[Biography:Karl Popper|Karl Popper]] stated the inverse. "Only if Plato's beard is sufficiently tough, and tangled by many entities, can it be worth our while to use Ockham's razor."<ref name="Popper1972">{{cite book
 | last = Popper
 | first = Karl
 | title = Objective Knowledge
 | publisher = Clarendon Press
 | date = 1972
 | url =https://www.marxists.org/reference/subject/philosophy/works/at/popper.htm
 }}</ref> Russell's theory of "singular descriptions", which clearly show "how we might meaningfully use seeming names without supposing that there be the entities allegedly named", is supposed to "detangle" Plato's beard.<ref>{{Cite book|title=Existence as a Real Property: The Ontology of Meinongianism|last=Berto|first=Francesco|publisher=Springer|year=2013|isbn=9789400742062|location=Dordrecht|page=28}}</ref><ref>{{Cite book|url=https://books.google.com/books?id=JYBUCwAAQBAJ&pg=PT627|title=An Historical Introduction to the Philosophy of Mathematics: A Reader|last1=Marcus|first1=Russell|last2=McEvoy|first2=Mark|date=11 February 2016|publisher=Bloomsbury Publishing|isbn=9781472529480|language=en}}</ref>

==See also==
*{{annotated link|Philosophy:Empty name}}
*{{annotated link|Extensional and intensional definitions}}
*{{annotated link|Philosophy:Meinong's jungle}}
*{{annotated link|Philosophy:Noneism}}
*{{annotated link|Philosophy:Ostensive definition}}

==References==
{{Reflist}}

==Further reading==
* {{cite journal|last=Durrant|first=Michael|year=1998|title=Plato's Quinean Beard: Did Plato ever grow it?|journal=Philosophy|volume=73|issue=1|pages=113–121|issn=0031-8191|doi=10.1017/S003181919700003X|s2cid=170709036 }}
* {{cite book|year=2004|title=The Blackwell Dictionary of Western Philosophy | isbn=978-1405191128 | doi=10.1111/b.9781405106795.2004.x|editor1-last=Bunnin|editor1-first=Nicholas|editor2-last=Yu|editor2-first=Jiyuan}}

==External links==

{{Paradoxes}}

{{DEFAULTSORT:Plato's Beard}}
[[Category:Logical paradoxes]]

{{Sourceattribution|Plato's beard}}