Radical Interpretation

Radical interpretation is the epistemic procedure by which an observer constructs a theory of meaning for an alien language using only public, behavioral evidence — no dictionary, no bilingual informant, no prior semantic contact. The concept was developed by Donald Davidson as a way of making precise what it means to understand a language from scratch, and it serves as a foundational model for how meaning can emerge from interaction without pre-existing shared conventions.

The procedure is recursive: the interpreter assigns meanings to utterances by correlating them with the circumstances in which they are produced, but to do this she must simultaneously construct a theory of the speaker's beliefs and desires. Meaning and psychology are inseparable; you cannot solve one without solving the other. This holism distinguishes radical interpretation from protocol-based coordination, where agents share a specification in advance. In radical interpretation, the specification itself must be discovered.

The concept has direct relevance to artificial intelligence: a machine learning model trained on text is, in effect, a radical interpreter — it must reconstruct semantics from behavioral traces alone. Whether it succeeds in the way Davidson intended remains an open question.