ABSTRACT
Varieties of supervenience have been distinguished, their pairwise logical relationships examined, and their usefulness for various purposes scrutinized. This chapter explores the core intuitive idea of supervenience. It argues that the possible-world versions of weak and strong supervenience do not imply, respectively, the modal-operator versions of weak and strong. The chapter also discusses an aspect of global supervenience, in particular what it is for two worlds to have the same total pattern of distribution of properties of a certain sort. It considers whether any variety of supervenience implies reduction. It examines the logical relationships between weak and global supervenience, and between strong and global. It provides some observations about multiple-domain weak and strong supervenience. The core idea of supervenience is, however, much simpler and easier than the stronger idea under consideration; the core is far better understood. The core idea gives us a firm intuitive grip on supervenience; the stronger idea cries out for explication.
