Abstract
Imagine the day when physics is complete. A theory is in place which unifies all the forces of nature in one self-consistent and empirically verified set of absolutely basic principles. There are some who see this day as perhaps not too distant (e.g. Hawking 1988, Weinberg 1992, Horgan 1996). Of course, the mere possession of this _theory_ of everything will not give us the ability to provide a complete _explanation_ of everything: every event, process, occurrence and structure. Most things will be too remote from the basic theory to admit of explanation in its terms; even relatively small and simple systems will be far too complex to be intelligibly described in the final theory