'Speaker's Meaning' is a study of language, charting the evolution of human consciousness through the gulf between a speaker's use of words and their lexical definition. This evolution is directly opposed to the currently held assumption that mind is a product of matter, and conscious awareness simply the reaction patterns of a stimulated organism. Barfield argues that there is an "inside" to both man and nature, and that the mutual development of both can be traced from pre-history to the present and future via the use of language.