 Virchow is credited as a founder of anthropology and of social medicine, frequently focusing on the fact that disease is never purely biological, but often socially derived or spread.As a co-founder and member of the liberal party "Deutsche Fortschrittspartei" he was a leading political antagonist of Bismarck.He was opposed to Bismarck's excessive military budget, which angered Bismarck sufficiently that he challenged Virchow to a duel in 1865.