Fragments of Parmenides 7

Come now, I will tell you—and do you hearken to my saying and carry it away—the only two ways of search that can be thought of. 

The first, namely, that It is, and that it is impossible for it not to be, is the way of belief, for truth is its companion. 

The other, namely, that It is not, and that it must needs not be—that, I tell you, is a path that none can learn of at all.