The MPIWG Research Report 2018–2020 presents the history of science not as a narrow study of past discoveries, but as an inquiry into the systems of knowledge through which societies organise, transmit and transform understanding. Its central emphasis is historical epistemology: the study of how knowledge practices emerge within specific cultural, material, institutional and technological conditions. The report shows that science cannot be separated from the infrastructures that sustain it, whether libraries, archives, laboratories, digital tools, research groups or international collaborations. This is especially evident in the Institute’s work on the Anthropocene, where science and technology are treated as historical forces that have helped produce the modern technosphere while also supplying the tools needed to diagnose planetary crisis. The case of Department I illustrates this approach clearly: its research links ancient measurement, early modern knowledge circulation, industrial energy systems and Earth system science into a long history of interaction between knowledge and material power. Digital humanities methods, including network analysis and machine learning, further demonstrate how contemporary historical research increasingly depends on computational infrastructures. Yet the report also suggests that such tools are not neutral: they reshape the questions historians ask and the scales at which knowledge can be analysed. Ultimately, the MPIWG’s work argues that understanding science historically is essential for understanding the present, because today’s crises—climate change, inequality, digitalisation and public distrust in science—are also crises in the organisation, legitimacy and circulation of knowledge.