Jonardon Ganeri defends a conception of language as essentially a means for the reception of knowledge through testimony. He argues that the possibility of testimony constrains the form of a theory of meaning. In particular, the semantic power of a word, its ability to stand for or take the place of a thing, derives from the epistemic powers of understanders, their capacity to acquire knowledge simply by understanding what is said.

Ganeri finds this account in the work of certain Indian philosophers of language, those belonging to the late classical school of Navya-Ny(ya. He presents a detailed analysis of their theories, paying particular attention to the influential seventeenth-century philosopher Gad(dhara. Ganeri examines the Indian account of the meaning relation and its relata, the role of modes of thought as meaning constituents, and the application of the theory to theoretical names and anaphora.

The aim of Semantic Powers is to give epistemology a central place in the study of language. It also shows how classical Indian theory of language can inform and be informed by contemporary philosophy.