Abstract
What factors are involved in the resolution of scientific disputes? What factors make the resolution of such disputes rational? The traditional view confers an important role on observation statements that are shared by proponents of competing theories. Rival theories make incompatible (sometimes contradictory) observational predictions about a particular situation, and the prediction made by one theory is borne out while the prediction made by the other is not. Paul Feyerabend, Thomas Kuhn, and Paul Churchland have called into question this account of theory-resolution. According to these philosophers, substantially different and competing scientific theories are semantically incommensurable: those theories do not share a common observation language. Two charges have been leveled against the semantic incommensurability theories. The first is that it ignores that some semantic features of observational terms (e.g., their reference) can be expressed by proponents of competing theories. The second is that the semantic incommensurability thesis is self-defeating. In this paper I will argue that both of these charges are true but not for the reasons usually given.