 What one looks for along this path of inquiry is what is and cannot not be, or, more simply, what must be. It is therefore appropriate to think of the first path as the path of necessary being and of what lies along it as what is (what it is) necessarily. What is and cannot not be will be whatever is (what it is) actually throughout the history of this world. Likewise, what is not and must not be will be whatever is not (anything) actually at any moment in the world’s history. There are of course other ways for things to be, but not, according to Parmenides, other ways for things to be such that apprehension of them will figure as understanding that does not wander. The second way is introduced alongside the first because the modality of necessary non-being or impossibility specified in fr. 2.5 is just as constant and invariable as the modality of necessary being specified in fr. 2.3. Whatever thought there may be about what lies along this second way will be unwavering and, as such, will contrast with the wandering thought typical of mortals. Even if the effort to think about what lies along the second way ends (as it does) in a total failure of apprehension, this non-apprehension remains unwavering. Inquiry along the second way involves, first, keeping in mind that what one is looking for is not and must not be, and thereby trying to discover what an entity that is in this way must be like. It is immediately evident, though, what an entity that is not and must not be is like: nothing at all. The goddess warns Parmenides not to set out on the second way because there is no prospect of finding or forming any conception of what must not be. She thus tells Parmenides at fr. 2.6 that this is a path where nothing at all can be learned by inquiry.