Statement (logic)

From Wikipedia, the free encyclopedia
Jump to: navigation, search

In logic a statement is either (a) a meaningful declarative sentence that is either true or false, or (b) that which a true or false declarative sentence asserts. In the latter case, a statement is distinct from a sentence in that a sentence is only one formulation of a statement, whereas there may be many other formulations expressing the same statement.

Philosopher of language, Peter Strawson advocated the use of the term "statement" in sense (b) 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) statements:

  • "Socrates is a man."
  • "A triangle has three sides."
  • "Madrid is the capital of Spain."

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."
  • "The King of France 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. Strawson held it is not a statement at all.

Statement 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.12

See also

Notes

  1. ^ Rouse
  2. ^ Ruzsa 2000, p. 16

References








Creative Commons License