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 is difficult because a collective attains over time a specific way of investigating, bringing with it a blindness to alternative ways of observing and conceptualization. Change was especially possible when members of two thought collectives met and cooperated in observing, formulating hypothesis and ideas. He strongly advocated comparative epistemology. This approach anticipated later developments in social constructionism, and especially the development of critical science and technology studies. 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