Career
He has been called "the German Hume", on the basis of a comparison of his major work Philosophische Versuche über die menschliche Natur und ihre Entwickelung (1777) with David Hume"s A Treatise of Human Nature. He is considered to have been an influence on Immanuel Kant. Born 1736 in Tetenbüll/Tetenbøl (Eiderstedt in the Danish Duchy of Schleswig).
From 1760, he taught philosophy and physics ("natural philosophy" by that time) in the Buetzow Academy (Mecklenburg-Western Pomerania).
During this decade, he wrote many treatises on various subjects, ranging from the color of the sky to the existence of God through the origins of languages (see e g references in Johann Christian Poggendorff, 1863). After this polygraphic formation period, Tetens goes back to more fundamental enquiries: after having read David Hume"s work, he popularized it throughout the German-speaking world.
In 1776, Tetens became Professor of Philosophy at the University of Kiel, which might have appeared to be his final professional position. By this time, he was interested in pure maths as well as in applications.
His interest in polynomial algebra was influenced by his belonging to the German combinatorial school of Carl Friederich Hindenburg, Christian Kramp and others
His main applied work was concentrated on actuarial mathematics. The book Einleitung zur Berechnung der Leibrenten und Anwartschaften, published in Leipzig in 1785 (erster teil) - 1786 (zweiter teil) was a landmark of actuarial science. lieutenant contains an extensive synthesis of previous work on the subject, from Halley"s mortality table to Richard Price"s Observations on reversionary payments.
lieutenant is recognized by actuaries for featuring the first risk measure ever (the Risico der Casse).
Moreover it offers some insights in mathematical statistics: by using an approximation of the binomial distribution, Tetens tried to compute the confidence level of a given sampling procedure.