As a philosopher he founded no "school", but his intellectual disciples could in some sense be said to include Josef Pieper, Luigi Giussani, Felix Messerschmid, Heinrich Getzeny, Rudolf Schwarz, Jean Gebser, Joseph Ratzinger (later Pope Benedict XVI), and Jorge Mario Bergoglio (later Pope Francis). In the 1980s Bergoglio began work on a doctoral dissertation on Guardini, though he never completed it. Pope Francis cited Guardini's "The End of the Modern World" eight times in his 2015 encyclical "Laudato si"', more often than any other modern thinker who was not pope. Hannah Arendt and Iring Fetscher were favourably impressed by Guardini's work. He had a strong influence in Central Europe; in Slovenia, for example, an influential group of Christian socialists, among whom Edvard Kocbek, Pino Mlakar, Vekoslav Grmič and Boris Pahor, incorporated Guardini's views in their agenda. Slovak philosopher and theologian Ladislav Hanus was strongly influenced in his works by Guardini, whom he met personally, and promoted his ideas in Slovakia, writing a short monograph. In 1952, Guardini won the Peace Prize of the German Book Trade.