The work of Gaston Bachelard is known for two crucial concepts, that of the epistemological rupture and that of phenomenotechnique. A crucial question is, however, how these two concepts relate to one another. Are they in fact essentially connected or must they be seen as two separate elements of Bachelard’s thinking? This paper aims to analyse the relation between these two Bachelardian moments and the significance of the concept of phenomenotechnique for today. This will be done by examining how the (...) concepts of Bachelard have been used from the 1960s on. From this historical perspective, one gets the impression that these two concepts are relatively independent from each other. The Althusserian school has exclusively focused on the concept of ‘epistemological break’, while scholars from Science & Technology Studies, such as Bruno Latour, seem to have only taken up the concept of phenomenotechnique. It in fact leads to two different models of how to think about science, namely the model of purification and the model of proliferation. The former starts from the idea that sciences are rational to the extent that they are purified and free from obstacles. Scientific objectivity, within this later model, is not achieved by eradicating all intermediaries, obstacles and distortions, but rather exactly by introducing as many relevant technical mediators as possible. Finally, such a strong distinction will be criticized and the argument will be made that both in Bachelard’s and Latour's thought both concepts are combined. This leads to a janus-headed view on science, where both the element of purification and the element of proliferation are combined. (shrink)