Ekstensionalismi

Ekstensionalismi is a philosophical concept primarily associated with the philosophy of language and logic. It deals with the meaning of words and propositions by referring to the objects, individuals, or states of affairs that they denote or describe. In simpler terms, the meaning of a term or sentence is understood by what it refers to in the real world or in a possible world.

This contrasts with intentionalism, which posits that meaning is determined by the concepts, ideas, or mental states associated with a term or sentence. Ekstensionalists would argue that two words or phrases have the same meaning if and only if they refer to the exact same set of things. For example, "the morning star" and "the evening star" refer to the same planet, Venus. Therefore, from an ekstensionalist perspective, they have the same extension and thus the same meaning, despite potentially invoking different sets of associated concepts.

In logic, the extension of a predicate is the set of all individuals to which the predicate applies. The extension of a sentence is its truth value (true or false). Ekstensionality is a fundamental principle in many formal systems, particularly in set theory and formal semantics, where the identity of sets or functions is determined by their members or the mappings they define, rather than by the way those members or mappings are described. The principle of ekstensionality is crucial for maintaining logical rigor and avoiding paradoxes that can arise from purely intensional interpretations.