Fragmentation and Singular Propositions

Two puzzles are described: a problem about necessary a posteriori truths and a problem about propositional attitudes with singular propositions as their contents. Two strategies for solving them are compared. The first is the diagonalization strategy, which distinguishes possible worlds that are compatible with what is actually expressed by a given sentential clause from possible worlds that are compatible with what would be expressed by the clause if that possible world were actual. The second strategy is the fragmentation strategy, which represents the intentional states described by sentential clauses as separate nonintegrated representational states. It is argued that these are complementary, not competing, strategies. Both play a role in the solutions to the problems. In conclusion, it is suggested that these strategies can also help to clarify a number of further problems—about self-locating attitudes, about the nature of computation, and about knowledge of phenomenal experience.