 A fourth area where the concept of intrinsically has been employed is to state recombination principles intended to describe what possible states of the world there are. (See Lewis 1986a.) An initial attempt to state such a principle might be (R1), where \(x\) is wholly distinct from \(y\) iff \(x\) and \(y\) have no parts in common. (As is standard in philosophical usage, each thing is counted as a part of itself. Hence, things are not wholly distinct from themselves.) 