The Foundations of the Nineteenth Century (Die Grundlagen des neunzehnten Jahrhunderts, 1899) is a racist book by British-born German philosopher Houston Stewart Chamberlain.
In the book, Chamberlain advances various racialist and especially völkisch antisemitic theories on how he saw the Aryan race as superior to others, and the Teutonic peoples as a positive force in European civilization and the Jews as a negative one.