Scientific realists defend the proposition that successful scientific theories in the mature sciences should be regarded as at least approximately true because that provides the best explanation of the fact that scientists use such theories successfully. Two important types of arguments against scientific realism are then considered. The historical argument appeals to the fact that seemingly successful theories have in the past turned out to be not even approximately true. The empiricist argument holds that because scientific realists believe claims about things that can never be observed, they violate the scientific commitment to subject claims to empirical assessment. Responses on behalf of scientific realism are considered. The chapter concludes by surveying engagements with realism in science that depart from the dialectic just sketched. These include considerations based on experimentation and experimental practice, varieties of structural realism, and perspectival realism.

Chapter 7 discussesa novel position in metaethics that the skeptical argument might give rise to: constructive deonticism. This position is structurally analogous to one of the most discussed anti-realist positions in science, Bas van Fraassen’s constructive empiricism. I start with an overview of van Fraassen’s view, discussing both its most important features and how it relates to its main rivals, scientific realism and logical positivism. Next, I flesh out the new position in ethics, focussing on the pragmatic understanding of moral explanation that it entails. Following this, I discuss how constructive deonticism should be classified as a metaethical position. I show that it is clearly not part of the expressivist family and at most half error theory (or fictionalism). However, the position is arguably not what realists are looking for either, instead prompting us to rethink how the metaethical realism debate has been framed. Finally, I point out what I consider to be the two most important challenges, i.e., whether we can draw such a sharp distinction bewteen deontic and explanatory claims and whether the position is a stable one.