Two Notions of Justification in Science

The sciences are not only the most sophisticated human enterprise of knowledge gathering, they are at the same time epistemically self-conscious to a considerable degree. Assessments of the epistemic status of data, inferences and theories play an important role in the very practice of science, which therefore includes a wealth of epistemic notions, norms and considerations. In one sense of the expression "epistemology of science�, some sort of an epistemology is thus included in scientific practice. This epistemology is usually captured under the heading of methodology, and its explication – e.g. concerning the standards of confirmation or theory choice – has also been a central business of the philosophy of science. Still, there are further epistemological questions about scientific knowledge claims that are typically not addressed within scientific practice. These include topics such as the underdetermination of theories by all evidence, the nomiracle argument, or the theory-dependence of observations. In the present paper, I will discuss the notion of justification that is operative in science and thus try to shed some light on the relation between the two epistemologies.