Frigyes Karinthy was a Hungarian author, playwright, poet, journalist, and translator. He was the first proponent of the six degrees of separation concept, in his 1929 short story, Chains (Láncszemek). Karinthy remains one of the most popular Hungarian writers. He was the brother of artist Ada Karinthy and the father of poet Gábor Karinthy and writer Ferenc Karinthy.
Frik was an Armenian poet of the 13th and 14th centuries. He wrote on both secular and religious topics, and many of his poems are characterized by social criticism. His verse is written in the spirit of religious fatalism.
Fritjof Capra is an Austrian-born American author, physicist, systems theorist and deep ecologist. In 1995, he became a founding director of the Center for Ecoliteracy in Berkeley, California. He is on the faculty of Schumacher College.
Fritsche Closener or Friedrich Klosener was a priest and historian of Strasbourg. His work was one of the first vernacular city chronicles, a type that became very common in Germany in the century that followed.
Fritz Berolzheimer, Juris Doctor was a German philosopher of law. He was the author of the five volume System der Rechts- und Wirtschaftsphilosophie (1904–07). In 1907 he co-founded the Archiv für Rechts- und Wirtschaftsphilosophie (ARWP).