The grammatical case is familiar to us as a morphological feature of declinable parts of speech. Historians of grammar credit the Stoic Chrysippus with having established the term ‘πτῶσις’—literally a ‘falling’—as the technical vocabulary for this notion of the grammatical case, as well as with having advanced a doctrine of five cases: the nominative (or ‘upright’) (ὀρθή) case, and the genitive (γενική), dative (δοτική), accusative (αἰτιατική), and vocative (κλητική) as the oblique (πλάγιαι) cases. However, despite the absence of an established technical vocabulary as part of an explicit doctrine of cases, the use of πτῶσις in the Aristotelian corpus suggests that he was already aware of the declension of names and nouns before the Stoics. This much is suggested in his discussion of the distinction between names (ὀνόματα) and cases of names (πτώσεις ὀνομάτων) at On Interpretation (De Int.) 16a32-b1. This passage is the locus classicus of a centuries-long debate in the history of grammatical theory, centered on a conceptual contradiction that arises from attributing casehood to the nominative, which would make it an ‘upright falling': how can something that is falling down be standing up? If one grants that the nominative is indeed a case, one is then on the hook for explaining what it falls from. It is on the basis of this passage that later ancient commentators deny that Aristotle counts the nominative as a case, despite the fact that the established vocabulary for the nominative that incites this problem in the first place does not appear in the Aristotelian corpus, nor would Aristotle himself have been aware of it. A further wrinkle is that against the view attributed to him in later antiquity, and against what we find in the De Int., at Prior Analytics 48b35-49a5 and Poetics 1457a21, Aristotle lists the nominative form of a word as an example of a case.
In order to adjudicate whether the nominative counts as a case for Aristotle, we must first reconstruct his account of case in general. My aim in this paper is to argue that for Aristotle, πτῶσις has both a broad and a narrow sense. Unlike competing interpretations, this reading renders all three passages internally consistent, for the nominative counts as a case on the broad understanding of πτῶσις but not on the narrow understanding. It also explains why the ancient commentators attribute to Aristotle the view that the nominative is not a case. This is significant for the history of grammatical theory, as it shows that even before the Stoics, there is a latent theoretical notion of grammatical case in Aristotle.