 But the gains are rather marginal, given the profound implications of Adams’ take on perspectivalism for propositional modal logic. Matters here turn on Adams’ understanding of what it is for a modal proposition \(\Diamond\varphi\) or \(\Box\varphi\) to be true at a possible world \(w\). Just as in the actual world, from a standpoint within another possible world \(w,\) a proposition \(\varphi\) that exists in \(w\) can be true at worlds where it doesn’t exist. \(\Diamond\varphi\)/\(\Box\varphi\) will thus be true from a standpoint in \(w\) if, from that perspective, \(\varphi\) is true at some/all worlds. But if \(\varphi\) does not exist in \(w\)—if, for example, \(\varphi\) is \(\neg \sfE!\sfa\) and \(w\) is Adams-free—then it is not available to be evaluated from a standpoint within \(w\) and, hence, from that standpoint, is neither true nor false at any world and, hence, neither possible nor necessary. For Adams, this means that, from our standpoint in the actual world, both \(\neg\Diamond\varphi\) and \(\neg\Box\varphi\) are true at \(w\):