Fichte developed Kant’s Critical philosophy into a system of his own, which he named ‘Theory of Science’ or Wissenschaftslehre. Though Fichte continued to revise this system until the end of his life, almost all of his best known and most influential philosophical works were written in first portion of his career, when he was a professor at the University of Jena.
The task of philosophy, as understood by Fichte, is to provide a transcendental explanation of ordinary consciousness and of everyday experience, from the standpoint of which philosophy must therefore abstract. Such an explanation can start either with the concept of free subjectivity (‘the I’) or with that of pure objectivity (the ‘thing in itself’), the former being the principle of idealism and the latter that of what Fichte called ‘dogmatism’ (or transcendental realism). Though neither of these first principles can be theoretically demonstrated, the principle of freedom possesses the advantage of being practically or morally certain. Moreover, according to Fichte, only transcendental idealism, which begins with the principle of subjective freedom and then proceeds to derive objectivity and limitation as conditions for the possibility of any selfhood whatsoever, can actually accomplish the task of philosophy.
One of the distinctive features of Fichte’s Jena system is its thoroughgoing integration of theoretical and practical reason, that is, its demonstration that there can be no (theoretical) cognition without (practical) striving, and vice versa. Another important feature is Fichte’s demonstration of the necessary finitude of all actual selfhood. The ‘absolute I’ with which the system seems to begin turns out to be only a practical ideal of total self-determination, an ideal toward which the finite I continuously strives but can never achieve. Also emphasized in Fichte’s Jena writings is the social or intersubjective character of all selfhood: an I is an I only in relationship to other finite rational subjects. This insight provides the basis for Fichte’s political philosophy or ‘theory of right’, which is one of the more original portions of the overall system of the Wissenschaftslehre, a system that also includes a foundational portion (or ‘first philosophy’), a philosophy of nature, an ethics and a philosophy of religion.
