L. L. Zamenhof L. L. Zamenhof Ludwik Lejzer Zamenhof (; , ; – ), credited as L. L. Zamenhof and sometimes as the pseudonymous Dr. Esperanto, was a Polish-Jewish ophthalmologist and the creator of Esperanto, the most successful constructed language in the world. He grew up fascinated by the idea of a world without war and believed that this could happen with the help of a new international auxiliary language, which he first developed in 1873 while still in school. Zamenhof was born on 15 December (3 December OS) 1859, the son of Markus Zamenhof (27 January 1837 - 29 November 1907) and
Ludwik Krzywicki Ludwik Krzywicki Ludwik Krzywicki (21 August 1859 – 10 June 1941) was a Polish anthropologist, economist and sociologist. One of the early champions of sociology in Poland, he approached historical materialism from a sociological viewpoint. From 1919 to 1936 he was a professor at the University of Warsaw. Ludwik Krzywicki was born at Płock in 1859 into an aristocratic but impoverished family. From an early age he showed an interest in psychology, philosophy and natural sciences, and studied the works of Darwin, Taine, Ribot and Comte. Krzywicki studied mathematics at the University of Warsaw in Congress Poland. After obtaining his