The semantic principle that the meaning of a complex expression is determined by the meanings of its constituent parts together with the rules used to combine them; often associated with Fregean semantics and recursive interpretation functions.

Principle

Meanings compose recursively: a semantic interpretation can be defined by specifying how atomic meanings combine via syntactic composition rules to yield meanings of larger expressions.

Demonstration

In formal semantics, the meaning of a sentence is computed by recursively applying function-argument composition: the denotation of 'P(x)' is obtained by applying the predicate denotation P to the argument denotation x according to composition rules.

Misapplication

Assuming strict compositionality for idioms, indexicals, context-dependent expressions, or phenomena where pragmatic or world-knowledge factors alter interpretation without adjusting part-meanings or combination rules.

Consequence

Enables systematic, modular semantic theories and algorithmic interpretation: lexical meanings plus composition rules suffice to compute sentence meanings in many formal frameworks.

Reversal

Holistic, contextualist, or emergent semantic views deny a strict compositional mapping from parts and rules to whole meaning, emphasizing pragmatic enrichment or global constraints.

Boundary

Applies to semantically productive phenomena where meanings of parts and syntactic combination are well-defined; it excludes or requires modification for fixed idioms, covert context-dependence, and certain non-compositional constructions.

Semantic Tension

Tension between compositionality and context-sensitivity: compositionality offers systematicity and learnability, while many linguistic facts (indexicals, implicatures, conventionalized idioms) push for context-sensitive or non-compositional accounts.

Synthesis

The principle of compositionality provides a working ideal: a recursive recipe permitting meanings of complex expressions to be built from parts plus combination rules, yet in practice it is supplemented by mechanisms for context, idioms, and pragmatic enrichment where strict compositionality fails.