The picture theory of language, also known as the picture theory of meaning, is a theory of linguistic reference

Reference

Reference is derived from Middle English referren, from Middle French rèférer, from Latin referre, "to carry back", formed from the prefix re- and ferre, "to bear"...

 and meaning articulated by Ludwig Wittgenstein

Ludwig Wittgenstein

Ludwig Josef Johann Wittgenstein was an Austrian philosopher who worked primarily in logic, the philosophy of mathematics, the philosophy of mind, and the philosophy of language. He was professor in philosophy at the University of Cambridge from 1939 until 1947...

 in the Tractatus Logico-Philosophicus

Tractatus Logico-Philosophicus

The Tractatus Logico-Philosophicus is the only book-length philosophical work published by the Austrian philosopher Ludwig Wittgenstein in his lifetime. It was an ambitious project: to identify the relationship between language and reality and to define the limits of science...

. Wittgenstein suggested that a meaningful proposition pictured a state of affairs

State of affairs

The state of affairs is that combination of circumstances applying within a society or group at a particular time. The current state of affairs may be considered acceptable by many observers, but not necessarily by all. The state of affairs may present a challenge, or be complicated, or contain a...

 or empirical

Empirical

The word empirical denotes information gained by means of observation or experimentation. Empirical data are data produced by an experiment or observation....

 fact

Fact

A fact is something that has really occurred or is actually the case. The usual test for a statement of fact is verifiability, that is whether it can be shown to correspond to experience. Standard reference works are often used to check facts...

. Wittgenstein compared the concept of logical pictures with spatial pictures. The picture theory of language is considered an early correspondence theory of truth

Correspondence theory of truth

The correspondence theory of truth states that the truth or falsity of a statement is determined only by how it relates to the world, and whether it accurately describes that world...

.

Wittgenstein's picture theory of language states that statements are meaningful if they can be defined or pictured in the real world.