propertythat

Propertythat is a theoretical term used in analytic philosophy and semantics to denote a class of properties defined by descriptive clauses introduced with the word that. It aims to capture how certain properties are specified by conditions rather than as single, fixed predicates—for example, "the property that is tall" or "the property that is blue and round." The term is exploratory and not widely standardized.

In formal logic, propertythat can be modeled as a function from a domain to a set of objects or truth-conditions defined by a defining clause. Given a clause C, propertythat(C) refers to the collection of all objects x such that C(x) holds. This allows analysis of how complex predicate descriptions map onto compatible properties.

Applications include philosophy of language, ontology, and knowledge-representation design. In education and thought experiments, propertythat helps illustrate how language describes attributes that depend on context or convention. In some models, it also informs reasoning about bundles of properties and their instantiation.

Example: the propertythat is tall includes all objects that satisfy tall, while the propertythat is blue and round includes all objects that meet both conditions.

Critics argue that the term risks vagueness and indeterminacy, since natural-language clauses vary in precision. Some highlight challenges in choosing a canonical defining clause and in separating propertythat from ordinary predicates or relational properties.

See also:

- Property

- Predicate

- Ontology

- Semantics

- Philosophy of language

- Trope theory