 In 1870, Windelband completed his dissertation on Die Lehren vom Zufall [Doctrines of chance] under Lotze’s supervision. The following year he served as a soldier in the German-French war. After his military service, he completed his habilitation in Leipzig and took up a position as “Privatdozent” there. His habilitation was published in 1873 under the title Ueber die Gewissheit der Erkenntniss: eine psychologisch-erkenntnisstheoretische Studie [On the certainty of knowledge: a psychological-epistemological study]. In 1874, Windelband married Martha Wichgraf with whom he would have four children.