Logical form (linguistics)
Encyclopedia
In the field of linguistics
, particularly in the minimalist program
, Logical Form (abbreviated LF), refers to a mental representation
of a linguistic expression, derived solely from Surface Structure. In the words of Chomsky
, LF captures "those aspects of semantic representation that are strictly determined by grammar, abstracted from other cognitive systems". LF is the semantic equivalent of Phonetic Form
(PF), a representation of the sound of a sentence derived from its surface structure.
Logical form is the level of representation which fully determines the semantics of a sentence. LF is sometimes referred to as a covert
level of representation, because the output of this level is not actually pronounced by the speaker. LF is posited in syntax in order to give a structural account of certain kinds of semantic
ambiguities. For example, the sentence,
is semantically ambiguous. Specifically, it contains a scope
ambiguity. This ambiguity cannot be resolved at surface structure, since someone, being within the verb phrase
, must be lower in the structure than everyone. This case exemplifies the general fact that natural language is insufficiently specified for strict logical meaning. Noam Chomsky
and his student Robert May argued for the postulation of LF partly in order to account for such ambiguities (among other motivations). At LF, the sentence above would have two possible structural representations, one for each possible scope-reading, in order to account for the ambiguity by structural differentiation. In this way it is similar in purpose to, but not the same as, Logical form
in logic
.
Generative semanticists
, however, have argued that ambiguities like the one in the example above should be resolved at deep structure
(or at least, some level of representation preceding surface structure in the derivation), in order to avoid positing covert movement.
Linguistics
Linguistics is the scientific study of human language. Linguistics can be broadly broken into three categories or subfields of study: language form, language meaning, and language in context....
, particularly in the minimalist program
Minimalist program
In linguistics, the Minimalist Program is a major line of inquiry that has been developing inside generative grammar since the early nineties. It started with a 1993 paper by Noam Chomsky....
, Logical Form (abbreviated LF), refers to a mental representation
Mental representation
A representation, in philosophy of mind, cognitive psychology, neuroscience, and cognitive science, is a hypothetical internal cognitive symbol that represents external reality, or else a mental process that makes use of such a symbol; "a formal system for making explicit certain entities or types...
of a linguistic expression, derived solely from Surface Structure. In the words of Chomsky
Chomsky
Chomsky Khomsk ") is a Belarus'-origin surname, and may refer to:* Aviva Chomsky , American historian* Carol Chomsky , American linguist and wife of Noam Chomsky* Elsie Chomsky, American educator...
, LF captures "those aspects of semantic representation that are strictly determined by grammar, abstracted from other cognitive systems". LF is the semantic equivalent of Phonetic Form
Phonetic form
In the field of linguistics, specifically in syntax, phonetic form , refers to a certain level of mental representation of a linguistic expression, derived from surface structure, and related to logical form. Phonetic form is the level of representation wherein expressions, or sentences, are...
(PF), a representation of the sound of a sentence derived from its surface structure.
Logical form is the level of representation which fully determines the semantics of a sentence. LF is sometimes referred to as a covert
Covert (linguistics)
In linguistics, a feature of a word or phrase is said to be covert if there is no surface evidence of its existence within that word or phrase. For example, many languages have covert grammatical gender in nouns, in that there is no way to tell from the form of a noun which gender it is; gender...
level of representation, because the output of this level is not actually pronounced by the speaker. LF is posited in syntax in order to give a structural account of certain kinds of semantic
Semantics
Semantics is the study of meaning. It focuses on the relation between signifiers, such as words, phrases, signs and symbols, and what they stand for, their denotata....
ambiguities. For example, the sentence,
- Everyone loves someone
is semantically ambiguous. Specifically, it contains a scope
Free variables and bound variables
In mathematics, and in other disciplines involving formal languages, including mathematical logic and computer science, a free variable is a notation that specifies places in an expression where substitution may take place...
ambiguity. This ambiguity cannot be resolved at surface structure, since someone, being within the verb phrase
Verb phrase
In linguistics, a verb phrase or VP is a syntactic unit composed of at least one verb and the dependents of that verb. One can distinguish between two types of VPs, finite VPs and non-finite VPs . While phrase structure grammars acknowledge both, dependency grammars reject the existence of a...
, must be lower in the structure than everyone. This case exemplifies the general fact that natural language is insufficiently specified for strict logical meaning. Noam Chomsky
Noam Chomsky
Avram Noam Chomsky is an American linguist, philosopher, cognitive scientist, and activist. He is an Institute Professor and Professor in the Department of Linguistics & Philosophy at MIT, where he has worked for over 50 years. Chomsky has been described as the "father of modern linguistics" and...
and his student Robert May argued for the postulation of LF partly in order to account for such ambiguities (among other motivations). At LF, the sentence above would have two possible structural representations, one for each possible scope-reading, in order to account for the ambiguity by structural differentiation. In this way it is similar in purpose to, but not the same as, Logical form
Logical form
In logic, the logical form of a sentence or set of sentences is the form obtained by abstracting from the subject matter of its content terms or by regarding the content terms as mere placeholders or blanks on a form...
in logic
Logic
In philosophy, Logic is the formal systematic study of the principles of valid inference and correct reasoning. Logic is used in most intellectual activities, but is studied primarily in the disciplines of philosophy, mathematics, semantics, and computer science...
.
Generative semanticists
Generative semantics
Generative semantics is the name of a research program within linguistics, initiated by the work of various early students of Noam Chomsky: John R. Ross, Paul Postal and later James McCawley...
, however, have argued that ambiguities like the one in the example above should be resolved at deep structure
Deep structure
In linguistics, specifically in the study of syntax in the tradition of generative grammar , the deep structure of a linguistic expression is a theoretical construct that seeks to unify several related structures. For example, the sentences "Pat loves Chris" and "Chris is loved by Pat" mean...
(or at least, some level of representation preceding surface structure in the derivation), in order to avoid positing covert movement.
See also
- Antecedent-contained deletionAntecedent-contained deletionAntecedent-contained deletion is a phenomenon found in Verb phrase ellipsis contexts containing a quantifier. To understand the issue involved, it is necessary to understand how VP-elision works. Consider the following examples, where the expected, but missing, VP is represented with the symbol Δ....
- Government and binding theoryGovernment and binding theoryGovernment and binding is a theory of syntax and a phrase structure grammar in the tradition of transformational grammar developed principally by Noam Chomsky in the 1980s...
(precursor to the Minimalist programMinimalist programIn linguistics, the Minimalist Program is a major line of inquiry that has been developing inside generative grammar since the early nineties. It started with a 1993 paper by Noam Chomsky....
) - Categorial grammarCategorial grammarCategorial grammar is a term used for a family of formalisms in natural language syntax motivated by the principle of compositionality and organized according to the view that syntactic constituents should generally combine as functions or according to a function-argument relationship...
External links
- SEP entry for logical form (general concept) covers LF in the Transformational Grammar section