When the 19th century in the philosophy of science witnessed the rise of positivism, the 20th century began with a crisis of positivist thinking, without any immediate solution or alternative in sight. Only gradually did a complex, socio-historically and intellectually motivated reflection on science develop throughout the 20th century, which fundamentally aimed to historicize the philosophy of science. Forms of historical epistemology emerged. This movement must be placed in the broader context of the dynamics of the sciences and the social and cultural developments of the 20th century. This introduction presents positions that intervened in and shaped this process of historicization.