 Parmenides of Elea (early 5th century bce) is arguably the first Greek philosopher to have focused on the problematic nature of intentionality. His poem (transmitted under the title On Nature) offers a startling revelation of the allegedly true nature of reality and appearance, in which the narrator is instructed by a goddess that “you cannot grasp or express what is not – it cannot be accomplished” (B2), for “thinking cannot be found apart from what is, upon which its expression depends” (B8.35–36) and “what can be said and thought must be what is” (B6). The Greek for the phrases ‘what is’ and ‘what is not’ are notoriously ambiguous. But if, as many interpreters maintain (see Owen 1960; Furth 1968), it should be construed here either in terms of (a) what does or does not exist, or (b) what is or is not the case, or perhaps (c) some fusion of the two, then the goddess is denying the possibility of thinking or speaking either about nonexistent objects, or about nonfactual states-of-affairs, or both, on the basis of the following intuitions. If one is to think or express anything at all, there must be something that one is thinking or expressing (thus quantifying in). But what is not, by hypothesis, is not there to be thought of (cf. B3), since either it does not exist or is not in fact the case; and if there isn’t anything there to be thought of, then we must not be thinking of anything either. Parallel problems are supposed to arise in the case of speech, for statements concerning a nonexistent or for false statements.