 Stalnaker maintains that whenever one fails to know or believe a necessary truth, \(A\), one actually fails to fully grasp the sentence \(A\)’s meaning: one doesn’t realize that \(A\) expresses the total set of worlds. Stalnaker points at the occasional distance between the syntactic structure of the relevant \(A\), which can be quite complex, and the expressed proposition—in SPWS, an unstructured entity (a set):