Note 20 — Chapter VI · ANALYTICA PRIORA II.
Reading edition
Analyt. Prior. II. xvi. p. 64, b. 33-p. 65, a. 9. Petere principium is, in the phrase of Aristotle, not τὴν ἀρχὴν αἰτεῖσθαι, but τὸ ἐν ἀρχῇ αἰτεῖσθαι or τὸ ἐξ ἀρχῆς αἰτεῖσθαι (xvi. p. 64, b. 28, 34).