Kundera also used the expulsion as an inspiration for the main theme of his novel Žert (The Joke, 1967). After Kundera graduated in 1952, the Film Faculty appointed him a lecturer in world literature. In 1956 Kundera was readmitted to the Party but was expelled for the second time in 1970. Along with other reformist communist writers such as Pavel Kohout, he was peripherally involved in the 1968 Prague Spring. This brief period of reformist activities was crushed by the Soviet invasion of Czechoslovakia in August 1968. Kundera remained committed to reforming Czechoslovak communism, and argued vehemently in print with fellow Czech writer Václav Havel, saying, essentially, that everyone should remain calm and that "nobody is being locked up for his opinions yet," and "the significance of the Prague Autumn may ultimately be greater than that of the Prague Spring." Finally, however, Kundera relinquished his reformist dreams and moved to France in 1975. He taught for a few years in the University of Rennes. He was stripped of Czechoslovak citizenship in 1979; he has been a French citizen since 1981. He maintains contact with Czech and Slovak friends in his homeland, but rarely returns and always does so without fanfare. Works Although his early poetic works are staunchly pro-communist, his novels escape ideological classification. Kundera has repeatedly insisted that he is a novelist rather than a politically motivated writer. Political commentary has all but disappeared from his novels since the publication of The Unbearable Lightness of Being except in relation to broader philosophical themes. Kundera's style of fiction, interlaced with philosophical digression, is greatly inspired by the novels of Robert Musil and the philosophy of Nietzsche, and is also interpreted philosophically by authors such as Alain de Botton and Adam Thirlwell. Kundera himself claims inspiration from Renaissance authors such as Giovanni Boccaccio, Rabelais, and perhaps most importantly, Miguel de Cervantes, to whose legacy he considers himself most committed. Other influences include Laurence Sterne, Henry Fielding, Denis Diderot, Robert Musil, Witold Gombrowicz, Hermann Broch, Franz Kafka, and Martin Heidegger. Originally he wrote in Czech, but from 1993 on he has written his novels in French. Between 1985 and 1987, he undertook the revision of the French translations of his earlier works himself. His books have also been translated into many other languages. The Joke In his first novel, The Joke (1967), he satirizes the totalitarianism of the Communist era. His criticism