High Quality Content by WIKIPEDIA articles! Paul Marie Ghislain Otlet (23 August 1868 in Brussels, Belgium ? 10 December 1944) was an author, entrepreneur, visionary, lawyer and peace activist; he is one of several people who have been considered the father of information science, a field he called "documentation". Otlet created the Universal Decimal Classification, one of the most prominent examples of faceted classification. Otlet was responsible for the widespread adoption in Europe of the standard American 3x5 inch index card used until recently in most library catalogs around the world (by now largely displaced by the advent of online public access catalogs (OPAC)). Otlet wrote numerous essays on how to collect and organize the world's knowledge, culminating in two books, the Traité de documentation.(1934) and Monde: Essai d'universalisme. (1935)