 Consider the case of the two gods. They inhabit a certain possible world, and they know exactly which world it is. Therefore they know every proposition that is true at their world. Insofar as knowledge is a propositional attitude, they are omniscient. Still I can imagine them to suffer ignorance: neither one knows which of the two he is. They are not exactly alike. One lives on top of the tallest mountain and throws down manna; the other lives on top of the coldest mountain and throws down thunderbolts. Neither one knows whether he lives on the tallest mountain or on the coldest mountain; nor whether he throws manna or thunderbolts. Surely their predicament is possible. (The trouble might perhaps be that they have an equally perfect view of every part of their world, and hence cannot identify the perspectives from which they view it.) But if it is possible to lack knowledge and not lack any propositional knowledge, then the lacked knowledge must not be propositional. If the gods came to know which was which, they would know more than they do. But they wouldn’t know more propositions. There are no more to know. (Lewis 1979: 520–521)