- Divine Origin Theory. Words are given to humans directly by a divine entity or through a supernatural act.
- Intentionalist Theory: Word meanings are shaped by what the individual speaker intends to communicate, regardless of conventional language norms.
- Constructivist Theory: Words are a constructed tool, deliberately invented and developed by humans to meet their communication needs.
- Conventionalist Theory: Words are products of social conventions and agreements among members of a language community over time.
- Naturalist Theory: Words have a natural basis. Humans, like other animals, naturally produce specific sounds in response to specific circumstances, leading to a natural foundation for each language. While cultural and social factors have influenced language development, there is a core link between words and their meanings that is rooted in human nature.
Epicurus and Metrodorus originally took a fully conventionalist view of language. By 296 BC, (when On Nature, Book 28 was written) Epicurus came to see that humans naturally created relationships between objects and words, just as animals naturally create a relationship between their circumstances and their vocalizations. Therefore, language is not purely conventional. There is, for any group of people in any environment, a natural connection between their words and the objects that they label.