The long-term task of phonetics is to contribute towards the construction of a theory of the use and form of spoken language. The choice of this objective is primarily scientifically motivated but is reinforced by the prospect of using phonetic knowledge for educational, clinical and technological purposes. Phonetics is relevant to the general study of spoken language in two ways: It enters into describing how language is used by speakers, listeners and learners (the psychology and physics of speech behavior) and accounting for how language is formed by the social and biological constraints on their vocal/auditory performance (the phylogeny and ontogeny of language form). Such a program is today served by phonetics oriented towards both natural science and behavioral experimentation and by general linguistics dominated by its quest for autonomy and a place in the tradition of speculative philosophy. While the immensity of the subject matter of spoken language certainly makes a multiplicity of empirical approaches mandatory, it is equally true that a broader paradigm lending theoretical unification to the mosaic of research cultures must be sought. This appears to be the case particularly with regard to the full exploitation of the theoretical and practical relevance of phonetics. The main point of the present paper is that such unification can be achieved by rejecting all attempts at making linguistics autonomous and hostile to ‘extralinguistic’ explanation and by embedding the study of language and speech, and thus phonetics, within the framework of biological functional