In recent years, it has become widely accepted that linguistic questions were much more central to the philosophical tradition of German idealism than had been previously thought. However, most of the key texts for this discussion remain largely unknown. The present work makes available, for the first time in English, what is the seminal work for this issue: Johann Gottlieb Fichte's monograph of 1795 entitled "On the Linguistic Capacity and the Origin of Language", together with other closely related essays. The translations are accompanied by a detailed interpretative essay that seeks to place these materials in their historical context, relate them to the systematic concerns of German idealism, and evaluate them in relation to later approaches to language, especially those of semiotics and post-structuralism.It also explores the role played by the linguistic thought of the German idealists in the emergence of modern "scientific linguistics" with Wilhelm von Humboldt, as well as its connections with the origins of German romanticism. While the book draws upon state-of-the-art scholarship in these areas, it is written in such a way as to be accessible to any serious student of philosophy, intellectual and literary history, and linguistics.