metaphysics Metaphysics is the branch of philosophy that examines the basic structure of reality. It is traditionally seen as the study of mind-independent features of the world, but some theorists view it as an inquiry into the conceptual framework of ...

, Plato's beard is a

paradox A paradox is a logically self-contradictory statement or a statement that runs contrary to one's expectation. It is a statement that, despite apparently valid reasoning from true or apparently true premises, leads to a seemingly self-contradictor ...

ical argument dubbed by

Willard Van Orman Quine Willard Van Orman Quine ( ; known to his friends as "Van"; June 25, 1908 – December 25, 2000) was an American philosopher and logician in the analytic tradition, recognized as "one of the most influential philosophers of the twentieth century" ...

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.

Doctrine

Quine defined

Plato Plato ( ; Greek language, Greek: , ; born BC, died 348/347 BC) was an ancient Greek philosopher of the Classical Greece, Classical period who is considered a foundational thinker in Western philosophy and an innovator of the writte ...

's beard – and his reason for naming it so – in the following words:

This is the old Platonic riddle of nonbeing. Nonbeing must in some sense be, otherwise what is it that there is not? This tangled
doctrine Doctrine (from , meaning 'teaching, instruction') is a codification (law), codification of beliefs or a body of teacher, teachings or instructions, taught principles or positions, as the essence of teachings in a given branch of knowledge or in a ...
might be nicknamed Plato's beard; historically it has proved tough, frequently dulling the edge of
Occam's razor In philosophy, Occam's razor (also spelled Ockham's razor or Ocham's razor; ) is the problem-solving principle that recommends searching for explanations constructed with the smallest possible set of elements. It is also known as the principle o ...
.

The argument has been favored by prominent philosophers including

Bertrand Russell Bertrand Arthur William Russell, 3rd Earl Russell, (18 May 1872 – 2 February 1970) was a British philosopher, logician, mathematician, and public intellectual. He had influence on mathematics, logic, set theory, and various areas of analytic ...

, A. J. Ayer and

C. J. F. Williams Christopher John Fardo Williams (31 December 1930 – 25 March 1997) was a British philosopher. His areas of interest were philosophical logic, on which topic he did most of his original work, and ancient philosophy, as an editor and translator. ...

. Declaring that not ''p'' (¬''p'') cannot exist, one may be forced to abandon

truism A truism is a claim that is so obvious or self-evident as to be hardly worth mentioning, except as a reminder or as a rhetorical or literary device, and is the opposite of a falsism. In philosophy, a sentence which asserts incomplete truth con ...

s such as

negation In logic, negation, also called the logical not or logical complement, is an operation (mathematics), operation that takes a Proposition (mathematics), proposition P to another proposition "not P", written \neg P, \mathord P, P^\prime or \over ...

and ''

modus tollens In propositional logic, ''modus tollens'' () (MT), also known as ''modus tollendo tollens'' (Latin for "mode that by denying denies") and denying the consequent, is a deductive argument form and a rule of inference. ''Modus tollens'' is a m ...

''. There are also variations to Quine's original, which included its application both to singular and general terms. Quine initially applied the doctrine to singular terms only before expanding it so that it covers general terms as well.

Karl Popper Sir Karl Raimund Popper (28 July 1902 – 17 September 1994) was an Austrian–British philosopher, academic and social commentator. One of the 20th century's most influential philosophers of science, Popper is known for his rejection of the ...

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." 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.

References

External links

* {{DEFAULTSORT:Plato's Beard Willard Van Orman Quine Logical paradoxes Abstract object theory

Doctrine

See also

References

Further reading

External links