Johann Gottlieb Fichte (Stanford Encyclopedia of Philosophy), Daniel Breazeale.
Inspired by his reading of Kant, Johann Gottlieb Fichte (1762–1814) developed during the final decade of the eighteenth century a radically revised and rigorously systematic version of transcendental idealism, which he called Wissenschaftslehre of “Doctrine of Scientific Knowledge.” Perhaps the most characteristic, as well as most controversial, feature of the Wissenschaftslehre (at least in its earlier and most influential version) is Fichte's effort to ground his entire system upon the bare concept of subjectivity, or, as Fichte expressed it, the “pure I.” During his career at the University of Jena (1794–1799) Fichte erected upon this foundation an elaborate transcendental system that embraced the philosophy of science, ethics, philosophy of law or “right.” and philosophy of religion.