semantics

Branch of linguistics dealing with the meaning of words and sentences. Semantics asks how we can use language to express things about the real world and how the meanings of linguistic expressions can reflect people's thoughts. Semantic knowledge is compositional; the meaning of a sentence is based on the meanings of the words it contains and the order they appear in. For example, the sentences ‘Teachers love children’ and ‘Children love teachers’ both involve people loving other people but because of the different order of words they mean different things.

Linguistic meaning has been studied for thousands of years. Plato believed that words or phrases related directly to the actual objects they pick out. Aristotle suggested that relationships between words and the world are indirect, mediated by social convention. More recently, the conceptualist view of linguistic meaning has held that there is an indirect relationship between words and things, mediated by thoughts in the mind.

The philosopher Gottlob Frege drew a distinction between the sense of a linguistic expression and its reference (the thing in the world that it picks out). So the meaning of a natural language expression is equivalent to both sense and reference; for example, the phrases ‘the morning star’ and ‘the evening star’ have different senses, but both have the same reference – namely, the planet Venus. Some linguistic expressions can have a reference but no sense (such as the name ‘Fred’), and some may have sense but no reference (such as ‘the present King of France’).

Recent work in semantics has been examining the semantic underdeterminacy thesis, which holds that natural language sentences usually leave a lot to the imagination – they do not provide all the information needed for their meaning to be understood, and further processing is necessary for an interpretation to be reached. For instance, the phrase ‘Stop it!’ may have a clear meaning if the person who hears it has information about the context in which it is said, but as a sentence on its own it is not clear what should be stopped and who should stop it.