This volume presents Fichte?s foundational treatise of 1794/95, Grundlage der gesamten Wissenschaftslehre. In it the author elaborates the systematic groundwork of his ?science of knowledge? (Wissenschaftslehre), positioning the act of self?positing of the I at the apex of his philosophical architecture. With the second edition of 1802 and its further receptions in mind, this edition includes editorial introduction by Wilhelm?G.?Jacobs and a full register. Essential reading for the study of German idealism and transcendental philosophy. This work marks the central philosophical breakthrough of Johann?Gottlieb?Fichte: here he develops a radically new form of transcendental philosophy, the ?science of knowledge? (Wissenschaftslehre). Beginning from the idea that the ?I? must posit itself, he derives in a rigorous and systematic way the structure of knowledge, experience and freedom. The work is divided into an introductory part of Grundsätze (principles), then into a theoretical section and finally into a practical section. Thus Fichte links the conditions of knowledge with the human act of freedom and moral responsibility. The volume under discussion is a modern reprint of the 1794 manuscript ?as lecture notes for his auditors?, including a scholarly introduction and annotations. It offers the reader direct access to the dynamic of Fichte?s early system, which became foundational for later German Idealism. Johann?Gottlieb?Fichte (1762?1814) was a German philosopher who followed in the lineage of Immanuel?Kant but moved philosophy forward by focusing on the active ?I? as the foundation of all knowledge and freedom. Born in Rammenau (Saxony), he studied theology and philosophy and rose quickly to prominence after his Versuch einer Critik aller Offenbarung (1792). In 1794 he was appointed professor in Jena and in that winter semester delivered the lectures that became the Grundlage der gesamten Wissenschaftslehre, thus inaugurating his Wissenschaftslehre. Over his life Fichte revised his system repeatedly and contributed greatly to ethics, pedagogy, political philosophy and the theory of the self. His work paved the way for the German idealist movement, influencing and being commented on by later figures such as Schelling and Hegel.