In the summer of 1790 a private tutor in Leipzig, twenty-eight years old and without a degree, began reading Kant because one of his pupils wanted lessons on him. Until then Johann Gottlieb Fichte had been caught, by his own account, between two loyalties: his reason told him that every human act is fixed by a chain of causes, and his moral convictions told him the opposite. Kant's practical philosophy let him keep both. Fichte called the reading a revolution in his way of thinking, and he spent the rest of his life building a philosophy on the freedom it had given back to him.
He had come a long way to that pupil. Fichte was the eldest son of a ribbon weaver in Rammenau, a village in Upper Lusatia, and his schooling began with a sermon. Ernst Haubold von Miltitz, a local landowner, arrived too late to hear the pastor preach and was told that a village boy could repeat the sermon almost word for word. Miltitz paid for the boy's education, which took him in 1774 to Pforta, the boarding school near Naumburg; the landowner died that same year. When the family's support ran out, Fichte left his theology studies at Jena and Leipzig without a degree and lived for years as a house tutor, work he came to detest.
Kant then made him famous, by accident. In 1791 Fichte travelled to Königsberg, was disappointed by his interview with Kant, and within weeks had written a manuscript and submitted it to him. Kant recommended it to his own publisher, and in 1792 Attempt at a Critique of All Revelation appeared without the author's name; readers took it for Kant's. When Kant named the real author, the unknown tutor became a celebrity, and in May 1794 he took up a professorship at Jena.
What he brought there was an answer to a problem Kant had left open. Kant had divided the world into things as they appear to us and things as they are in themselves, which no one can know, and sceptics were already attacking the division. Fichte's Wissenschaftslehre — his "doctrine of science", or theory of knowledge — gave up the unknowable thing in itself. Philosophy must begin from the I, and the I is not a thing that later acts: it is an activity that exists by positing itself. The world first shows up as the Not-I, the resistance this activity meets. Freedom comes first, and knowing grows out of doing. In the First Introduction to the Wissenschaftslehre of 1797 he conceded that no argument could force anyone to start from freedom rather than from things, and that the philosophy a person chooses depends on the kind of person they are.
His view of religion cost him the chair at Jena. In 1798 an essay in his own journal identified God with the living moral order of the world; an anonymous pamphlet charged him with atheism, and Saxony confiscated the issue. In the Atheism Dispute that followed, Fichte wrote a letter threatening to resign if he were reprimanded; it was taken as his resignation, and by the summer of 1799 he was in Berlin. That year Friedrich Heinrich Jacobi, the philosopher and novelist, called his philosophy nihilism in an open letter, and Kant declared the Wissenschaftslehre a wholly untenable system.
Berlin had no university then, and Fichte lived by private lectures and popular books such as The Vocation of Man, while rewriting his system more than a dozen times and publishing almost none of the new versions. In French-occupied Berlin, in the winter of 1807–08, he gave the Addresses to the German Nation, a call for a new national education. When the University of Berlin opened in 1810 he became the first dean of its philosophy faculty, and in 1811 its first elected rector. He resigned in February 1812 after the senate overruled him in the case of Brogi, a Jewish medical student who had been struck by another student and was now threatened with expulsion himself. In an anonymous pamphlet of 1793, Fichte had called Jewry a hostile state within the state. Scholars disagree on how to weigh the Brogi case against the pamphlet. In January 1814, at fifty-one, he died of the typhus his wife had caught while nursing wounded soldiers.
Schelling and Hegel, who had both learned from him, dismissed the Wissenschaftslehre as a one-sided, merely subjective idealism, and for more than a century Fichte was read chiefly as the author of the Addresses, hailed and vilified as a founder of German nationalism. His revival as a philosopher owes much to a critical edition begun by the Bavarian Academy of Sciences in 1962. Its forty-two volumes, completed in 2012, include the Berlin versions of the system. Fichte always insisted that they say what the Jena versions said; whether they do is still debated.