|David K. Lewis: a thought experiment concerning two omniscient gods (omniscient with respect to propositions). None of them knows who he is because that is not comprehensible in propositions. Self-knowledge is not propositional knowledge. (D.K. Lewis Philosophical Papers Vol. I 1983, p 139ff)|
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Two Omniscient Gods/2 Gods/Lewis: the example is to show that objects of attitudes should not be identified with propositions as sets of possible worlds - E.g. both know exactly the world they inhabit - i.e. they know every true proposition - but do not know who they are themselves - Solution: self-attribution of a property, not a proposition - (see above spatial (not logical) localization is not propositional knowledge).
LewisVsCastaneda: Solution: de se: we just need to find a case where the editor of soul knows which world is his without knowing if he is among the millionaires - de se: self-identification, self-localization - de dicto: self-localization in logical space (which proposition one believes).
Two omniscient gods/Lewis: E.g. assuming a variant with two pairs of two gods in two possible worlds W and V, who swapped places - Assuming God 1 knows that the proposition "I’m on the highest" is true in W - and he knows that he lives in W! - It does not follow that he knows that he is on the highest! - Because if he had been on the coldest, the same sentence would have expressed a different proposition, one that is true in V and wrong in W - one of which he knew that it is false.
Die Identität von Körper und Geist Frankfurt 1989
Konventionen Berlin 1975
Philosophical Papers Bd I New York Oxford 1983
Philosophical Papers Bd II New York Oxford 1986
Cl. I. Lewis
Mind and the World Order: Outline of a Theory of Knowledge (Dover Books on Western Philosophy) 1991