Andreas A.M. Kinneging studies political science at the Catholic University of Nijmegen. In 1990 he was appointed professor of political science at the University of Leiden. Currently he is director of research in the history of political theory in state agencies. He is the author of various works (in Dutch), including Liberalism in Political Economy, Philosophical Foundations of Liberalism, The Philosophy of Classical Liberalism, and briefer writings in the periodical literature.
Nicolai Hartmann (1882-1950) was born in 1882 in Riga, Latvia, to German parents. He studied philosophy and classics, first in St. Petersburg and later in Marburg, where he was appointed to a chair of philosophy in 1920. In 1931, after a short time at the University of Cologne, Hartmann was offered the prestigious chair of philosophy by the University of Berlin, where he lectured until the end of the war, untainted by Nazism. From 1945 until his death in 1950, he held a chair of philosophy at the University of Göttingen.