Why two articles: τῆς αἰσθήσεως τῆς κυρίας

Aristotle, On Sleep, 456a5, has this: καὶ ἡ ἀρχὴ τῆς κινήσεως καὶ τῆς αἰσθήσεως τῆς κυρίας ἐντεῦθέν ἐστιν.

Commentators and translators read this as “And the beginning of the movement and of the main perception is there.”

In the underlined phrase, why are there two articles? Why does this not say “of the perception of the chief thing”?

This looks like an attributive adjective using the less common “article - noun - article (repeated) - modifier” position. See Mastronarde, unit 7, page 64.

I don’t know for what affect the author would chose that attributive position, but it seems to be grammaticaly correct, and equivalent to the most common “article - modifier - noun” position.

This is simply an idiomatic use of the article with an adjective. See Smyth 1158:

  1. (2) Less often, the article and the attributive follow the noun preceded by the article: ὁ ἀνὴρ ὁ σοφός the wise man. Thus, ““τὸ στράτευμα τὸ τῶν Ἀθηναίων” the army of the Athenians” T. 8.50, ““ἐν τῇ πορείᾳ τῇ μέχρι ἐπὶ θάλατταν” on the journey as far as the sea” X. A. 5.1.1. In this arrangement the emphasis is on the noun, as something definite or previously mentioned, and the attributive is added by way of explanation. So τοὺς κύνας τοὺς χαλεποὺς διδέα_σι they tie up the dogs, the savage ones (I mean) X. A. 5.8.24.

http://www.perseus.tufts.edu/hopper/text?doc=Smyth+grammar+1158&fromdoc=Perseus%3Atext%3A1999.04.0007

It adds a slight emphasis to the adjective, similar to italics in English.

Why does this not say “of the perception of the chief thing”?

κυρίας is an adjective, not a noun.

Terrific! Thanks!