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Single Idea 8076

[filed under theme 19. Language / D. Propositions / 2. Abstract Propositions / a. Propositions as sense ]

Full Idea

The distinction between sentences and the abstract propositions that they express is one of the key ideas of logic. A logical argument consists of propositions, assembled together in a systematic fashion.

Gist of Idea

The distinction between sentences and abstract propositions is crucial in logic

Source

Keith Devlin (Goodbye Descartes [1997], Ch. 2)

Book Ref

Devlin,Keith: 'Goodbye Descartes: the end of logic' [Wiley 1997], p.27


A Reaction

He may claim that arguments consist of abstract propositions, but they always get expressed in sentences. However, the whole idea of logical form implies the existence of propositions - there is something which a messy sentence 'really' says.


The 13 ideas from Keith Devlin

Sentences of apparent identical form can have different contextual meanings [Devlin]
How do we parse 'time flies like an arrow' and 'fruit flies like an apple'? [Devlin]
The distinction between sentences and abstract propositions is crucial in logic [Devlin]
Space and time are atomic in the arrow, and divisible in the tortoise [Devlin]
'No councillors are bankers' and 'All bankers are athletes' implies 'Some athletes are not councillors' [Devlin]
Where a conditional is purely formal, an implication implies a link between premise and conclusion [Devlin]
Golden ages: 1900-1960 for pure logic, and 1950-1985 for applied logic [Devlin]
Modern propositional inference replaces Aristotle's 19 syllogisms with modus ponens [Devlin]
Predicate logic retains the axioms of propositional logic [Devlin]
People still say the Hopi have no time concepts, despite Whorf's later denial [Devlin]
Situation theory is logic that takes account of context [Devlin]
Montague's intensional logic incorporated the notion of meaning [Devlin]
Logic was merely a branch of rhetoric until the scientific 17th century [Devlin]