Science, Practice, and Justification: the A Priori Revisited

History is descriptive. Epistemology is conceived as normative. It appears, then, that a historical approach to epistemology, like historical epistemology, might not be epistemically normative. In our context here, epistemology is not a systematic theory of knowledge, truth, or justification. In this thesis I approach epistemic justification through the vantage point of practice of science. Practice is about reasoning. Reasoning, conceived as the human propensity to order perceptions, beliefs, memories, etc., in ways that permit us to have understanding, is not only about thinking. Reasoning has to do with our actions, too: In the ordering of reasoning we take into account the desires of ourselves and others. Reasoning has to do with tinkering with stuff, physical or abstract. Practice is primarily about skills. Practices are not mere groping. They have a form. Performing according to a practice is an activity with a lot of plasticity. The skilled performer retains the form of the practice in many different situations. Finally, practices are not static in time. Practices develop. People try new things, some of which may work out, others not. The technology involved in how to go about doing things in a particular practice changes, and the concepts concerning understanding what one is doing also may change. This is the point where history enters the picture. In this thesis I explore the interactions between history, reasoning, and skills from the viewpoint of a particular type of epistemic justification: a priori justification. An a priori justified proposition is a proposition which is evident independent of experience. Such propositions are self-evident. We will make sense of a priori justification in a context of regarding science as practice, so that we will be able to demonstrate that the latter accommodates the normative character of science.