Currently, there is not yet a full-fledged philosophical sub-discipline devoted to artifacts. In order to establish such a general philosophical discourse on artifacts, two topics are of special importance: artifact functionality and artifact categorization. Both are central to the question of what artifacts are in general and in particular. This introduction first presents the current state of the art in the debates on functions, both in general and in the domain of artifacts in particular. It then unfolds the three debates relevant for artifact kinds, namely the ontological, epistemological and semantic debates on artifact categorization, and presents the most important theory options currently under scrutiny in these fields. It proceeds by introducing the contributions in this special issue on the functions and kinds of art works and other artifacts, and discusses possible perspectives for a general philosophy of artifacts.