The theory and practice of translation can be enhance by a functional view of language in which different systms, interrelated but indepently variable, perform their work simultaneously with the message. In the present article, the author claims that the basic unit of discourse organization is the message, and that it is informed by the interaction of the theme system, which sets the stage, and the information system, which deliver the writer's 'point' through universally understood protocols. An appreciation of this 'anatomy' can guide the translator in examining the discourse structure of the source message and in replicating this structure so that a cohesive text is produced in the receptor language.