 A final view about the nature of narrow content has some striking structural resemblances to the idea of a diagonal proposition, but is motivated very differently. This is the view of David Chalmers (1996, 2002); a related view has been defended by David Lewis (1979, 1994). In a nutshell, the view construes narrow contents as sets of maximal epistemic possibilities, or scenarios. (Scenarios closely resemble the centered worlds used to define diagonal propositions. Whether there is a centered world for every scenario, and vice versa, are debated issues: see Chalmers 2006, section 3.4.) The motivation for this view requires some development.