the formation of our concept of Europe. Patočka increasingly focused on the idea of Europe during the 1970s. As he was banned from teaching (see below), he held clandestine lectures in his private apartment on the Greek thought in general and on Plato in particular in the late 70s. These clandestine lectures are collectively known as Plato and Europe, and they are published under the same title in English. He also entered into discussions about modern Czech philosophy, art, history and politics. He was an esteemed scholar of Czech thinkers such as Komensky (b.1592) (also known as Comenius) and Masaryk (b.1850). In 1971, he has published a small treatise on Comenius in German titled Die Philosophy der Erziehung des J.A. Comenius (Comenius's Philosophy of Education). In 1977, his work on Masaryk culminated in 'Two Studies on Masaryk, which was initially a privately circulated typescript. Patočka's Heretical Essays in the Philosophy of History is analyzed at length and with much care in Jacques Derrida's important book The Gift of Death. Derrida was the most recent person who wrote or conversed with Patočka's thought; Paul Ricoeur and Roman Jakobson (who respectively wrote the preface and afterword to the French edition of the Heretical Essays) are two further examples. During the years 1939–1945, when the Czech universities were closed, as well as between 1951 and 1968, and from 1972 on, Patočka was banned from teaching. Only a few of his books were published and most of his work circulated only in the form of typescripts kept by students and disseminated mostly after his death. Along with other banned intellectuals he gave lectures at the so-called "Underground University", which was an informal institution that tried to offer a free, uncensored cultural education. In January 1977 he became one of the original signatories and main spokespersons for the Charter 77 (Charta 77) human rights movement in Czechoslovakia. For the three months after the Charter was released he was intensely active writing and speaking about the meaning of the Charter, in spite of his deteriorating health. He was also interrogated by the police regarding his involvement with the Charter movement. On March 3, 1977 he was held by the police for ten hours, who had claimed that he would be allowed to speak in his role as a Charter spokesperson with a high-ranking official (in fact, this was a pretext to keep him from attending a