statement (logic)
{{merge to|Proposition|discuss=Talk:Proposition#Merger_proposal|date=December 2024}}
{{short description|Declarative sentence that is true or false, or an assertion made by the sentence}}
In logic and semantics, the term statement is variously understood to mean either:
- a meaningful declarative sentence that is true or false,{{Citation needed|date=December 2024}} or
- a proposition. Which is the assertion that is made by (i.e., the meaning of) a true or false declarative sentence.{{harvtxt|Millican|1994}} "Central to the [Strawsonian tradition] is the distinction between a sentence and what is said by a sentence - Strawson initially called the latter a use of a sentence, and sometimes a proposition, but his most frequent term for what is said, which Wolfram consistently adopts, is the statement expressed."{{harvtxt|Rouse|2005}} "A statement is defined as that which is expressible by a sentence, and is either true or false... A statement is a more abstract entity than even a sentence type. It is not identical
with the sentence used to express it... [That is,] different sentences can be used to express the same statement."
In the latter case, a (declarative) sentence is just one way of expressing an underlying statement. A statement is what a sentence means, it is the notion or idea that a sentence expresses, i.e., what it represents. For example, it could be said that "2 + 2 = 4" and "two plus two equals four" are two different sentences expressing the same statement. As another example, consider that the Arabic numeral '7', the Roman numeral 'VII', and the English word 'seven' are all distinct from the underlying number.{{sfn|Rouse|2005}}
Overview
Philosopher of language Peter Strawson (1919–2006) advocated the use of the term "statement" in sense (2) in preference to proposition. Strawson used the term "statement" to make the point that two declarative sentences can make the same statement if they say the same thing in different ways. Thus, in the usage advocated by Strawson, "All men are mortal." and "Every man is mortal." are two different sentences that make the same statement.
In either case, a statement is viewed as a truth bearer.
Examples of sentences that are (or make) true statements:
- "Socrates is a man."
- "A triangle has three sides."
- "Madrid is the capital of Spain."
Examples of sentences that are also statements, even though they aren't true:
- "All toasters are made of solid gold."
- "Two plus two equals five."
Examples of sentences that are not (or do not make) statements:
- "Who are you?"
- "Run!"
- "Greenness perambulates."
- "I had one grunch but the eggplant over there."
- "King Charles III is wise."
- "Broccoli tastes good."
- "Pegasus exists."
The first two examples are not declarative sentences and therefore are not (or do not make) statements.
The third and fourth are declarative sentences but, lacking meaning, are neither true nor false and therefore are not (or do not make) statements. The fifth and sixth examples are meaningful declarative sentences, but are not statements but rather matters of opinion or taste. Whether or not the sentence "Pegasus exists." is a statement is a subject of debate among philosophers. Bertrand Russell held that it is a (false) statement.{{Citation needed|date=September 2019}} Strawson held it is not a statement at all.{{Citation needed|date=September 2019}}
As an abstract entity
In some treatments, "statement" is introduced in order to distinguish a sentence from its informational content. A statement is regarded as the information content of an information-bearing sentence. Thus, a sentence is related to the statement it bears like a numeral to the number it refers to. Statements are abstract logical entities, while sentences are grammatical entities.{{sfn|Rouse|2005}}{{sfn|Ruzsa|2000|p=16}}
See also
References
{{reflist}}
=Works cited=
- {{cite book
|last=Rouse
|first=David L.
|title=A Practical Introduction to Formal Logic.
|chapter=Sentences, Statements and Arguments
|chapter-url=http://people.uvawise.edu/philosophy/Logic%20Text/Chapter%202%20Sentences,%20Statements%20and%20Arguments.pdf
|url=http://people.uvawise.edu/philosophy/Logic%20Text/Contents.htm
|year=2005
}}
- {{citation |last=Ruzsa |first=Imre |title=Bevezetés a modern logikába |series=Osiris tankönyvek |publisher=Osiris |publication-place=Budapest |year=2000 |isbn=963-379-978-3}}
- {{cite web |url=https://www.millican.org/papers/1994Wolfram.pdf |title=Statements and Modality: Strawson, Quine and Wolfram |author-link=Peter Millican |last=Millican |first=Peter |year=1994}}
Further reading
- A. G. Hamilton, Logic for Mathematicians, Cambridge University Press, 1980, {{ISBN|0-521-29291-3}}.
- {{cite journal
|title = Sentence and Statement: Prof. Quine on Mr. Strawson
|last = Xenakis
|first = Jason
|journal = Analysis
|issn = 1467-8284
|volume = 16
|issue = 4
|year = 1956
|pages = 91–4
|doi = 10.2307/3326478
|jstor = 3326478
}}
- P. F. Strawson, "[https://web.archive.org/web/20110723034837/http://www.sol.lu.se/common/courses/LINC04/VT2010/Strawson1950.pdf/ On Referring]" in Mind, Vol 59 No 235 (Jul 1950)
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