The proposition, termed glossogenetic isomorphism, briefly is that the relation of language to the world is that language directly mirrors the world. It is because of this mirroring that language is an effective instrument enabling us to describe the world, reason about it, perceive the relationships of objects and processes. Language makes science possible and makes our thought and consciousness possible. The approach is similar in outline to that of the early Wittgenstein in the Notebooks and the Tractatus but, going beyond this, the mirroring relationship of language to the world must be given a substantive content, entailing examination and development in the light of our vastly increased knowledge of the way the brain functions not only for language but for the faculties which language exists to represent, vision, action, the control of movement, emotional organisation. The thesis is developed more specifically in terms of the relation between the motor system and language (dealt with in my paper for the Berkeley meeting) which manifests itself in gestural iconicity in two senses, both visible iconicity of the body and the less easily perceived iconicity of articulation and word-structure. The presentation will include a demonstration of specific correspondences between speech-sounds and gesture, and between word-structures and word-meanings. Finally there will be some observations about the relation between these ideas and central philosophical topics.