Louis-Christophe Zaleski-Zamenhof as not only the first such World Congress in the third millennium of the civil calendar but also the third century of Esperanto, reminding the delegates: "You came to discuss intercultural dialogue, the pressing need for which inspired the initiation of the international language. In fact, almost all his biographies relate the story of the young Ludwik Łazarz Zamenhof living in the multicultural city of Białystok, observing the animosity that then governed relations among the varied nationalities, not finding a commonly understandable language, a tool that was, as he said, necessary for dialogue among the respective cultures. Mutual dialogue enables
Ludwik Fleck Ludwik Fleck Ludwik Fleck (11 July 1896 – 5 June 1961) was a Polish and Israeli physician and biologist who did important work in epidemic typhus in Lwów, Poland, with Rudolf Weigl and in the 1930s developed the concepts of the ""Denkstil"" ("thought style") and the ""Denkkollektiv"" ("thought collective"). The concept of the "thought collective" defined by him is important in the philosophy of science and in logology (the "science of science"), helping to explain how scientific ideas change over time, much as in Thomas Kuhn's later notion of the "paradigm shift" and in Michel Foucault's concept of the "episteme".