Observability and scientific realism

The goal of this thesis is to explore the debate between Bas van Fraassen’s constructive empiricism and scientific realism. For this purpose I discuss the existence of observable and unobservable entities, the observation/theoretical dichotomy, inference to the best explanation, the no miracles argument, pessimistic induction, and epistemic risk. I strive to show that, contrary to the view of constructive empiricism, there is no clear demarcation line between observable and unobservable entities, and that not only naked eye observation but also the instrument-based observation plays an important role in acquiring knowledge. I agree with scientific realists that there is no highest point to the human power of observation; it is open-ended for further development. Moreover, naked eye observations are not themselves beyond doubt, as sometimes even naked eye observations deceive us. In that context, theoretical explanations help us to understand the real situation. As such, there is no reason to give more credit to naked eye observations than to instrument-mediated, theory-informed observations. Scientific realists are confident in their knowledge of unobservables, and reject the epistemic significance of the observable/unobservable distinction. To justify their knowledge of unobservables, they use inferences to the best explanation. Such inferences play an important role in choosing the best theory amongst a group of theories. For their part, constructive empiricists use what is called the ‘bad lot’ argument to refute these inferences. I try to show that such ‘bad lot’ arguments fail to succeed at undermining inferences to the best explanation. Following scientific realists, I assert that nothing is miraculous in the domain of science, and that we can be assured of the approximate truth of successful scientific theories. It is true that many contemporary scientific theories contradict previously successful scientific theories, but that does not compel us to be pessimistic about such contemporary theories. Instead of pessimism, we can have an optimistic attitude about the progress of science. Considering the different arguments of constructive empiricism and scientific realism, this thesis gives more credit to scientific realism than to constructive empiricism