Theories Looking for Domains. Nomic Truth Approximation by Domain Revision

The theory of nomic truth approximation essentially deals primarily with truth approximation by theory revision for a fixed domain. However, variable domains and a fixed theory can also be taken into account, where the main changes concern domain extensions and restrictions. In this chapter I will present a coherent set of definitions of ‘more truthlikeness’, ‘empirical progress’ and ‘truth approximation’ due to a revision of the ‘domain of intended applications’. This set of definitions seems to be the natural counterpart of the basic definitions of similar notions as far as theory revision is concerned.