Gottfried Wilhelm (von) Leibniz was a German polymath active as a mathematician, philosopher, scientist and diplomat. He is a prominent figure in both the history of philosophy and the history of mathematics. He wrote works on philosophy, theology, ethics, politics, law, history and philology. Leibniz also made major contributions to physics and technology, and anticipated notions that surfaced much later in probability theory, biology, medicine, geology, psychology, linguistics and computer science. In addition, he contributed to the field of library science by devising a cataloguing system whilst working at Wolfenbüttel library in Germany that would have served as a guide for many of Europe's largest libraries. Leibniz's contributions to a wide range of subjects were scattered in various learned journals, in tens of thousands of letters and in unpublished manuscripts. He wrote in several languages, primarily in Latin, French and German.
Gotthold Ephraim Lessing was a German philosopher, dramatist, publicist and art critic, and a representative of the Enlightenment era. His plays and theoretical writings substantially influenced the development of German literature. He is widely considered by theatre historians to be the first dramaturg in his role at Abel Seyler's Hamburg National Theatre.
Gottlieb Konrad Pfeffel was a French-German writer and translator from the Pfeffel family. His texts were put to music by Ludwig van Beethoven, Joseph Haydn and Franz Schubert. He is sometimes also known as Amédée or Théophile Conrad Pfeffel, which is the French translation of Gottlieb ("Godlove").
Gottlieb Mittelberger was a German author, schoolmaster, organist, and Lutheran pastor. He was best known for his work Journey to Pennsylvania (1756). Mittelberger's travelogue provides a firsthand historic account of the misery and exploitation of German immigrants during the US colonial period. In his work, he tries to convince his fellow Germans not to immigrate to the American colonies, as the forfeiture of freedom, cost of money, lack of health, and loss of life are too exorbitant to risk and sacrifice. Although never an indentured servant, Mittelberger's written testament is one of several surviving historic works describing the hardships of the redemption system.
