 The two ways of inquiry that lead to thought that does not wander are: “that [it] is and that [it] is not not to be” (fr. 2.3)—i.e., “that [it] is and that [it] cannot not be”—and “that [it] is not and that [it] must not be” (fr. 2.5). Each verse appears to demarcate a distinct modality or way of being. One might find it natural to call these modalities, respectively, the modality of necessary being and the modality of necessary non-being or impossibility. Parmenides conceives of these modalities as ways of being or ways an entity might be rather than as logical properties. If one respects the organizing metaphor of the ways of inquiry, one can, even at this stage of the goddess’ revelation, appreciate what it means for “that [it] is and that [it] cannot not be” to define a way of inquiry. This specification indicates that what Parmenides is looking for is what is and cannot not be—or, more simply, what must be. Pursuing this way of inquiry requires maintaining a constant focus on the modality of the object of his search as he tries to attain a fuller conception of what an entity that is and cannot not be, or that must be, must be like. To remain on this path Parmenides must resolutely reject any conception of the object of his search that proves incompatible with its mode of being, as the goddess reminds him at numerous points.