EN 1096a29-34 There are many sciences even of things under one category

ἔτι δ' ἐπεὶ τῶν κατὰ μίαν ἰδέαν μία καὶ ἐπιστήμη, καὶ τῶν ἀγαθῶν ἁπάντων ἦν ἂν μία τις ἐπιστήμη· νῦν δ' εἰσὶ πολλαὶ καὶ τῶν ὑπὸ μίαν κατηγορίαν, οἷον καιροῦ, ἐν πολέμῳ μὲν γὰρ στρατηγικὴ ἐν νόσῳ δ' ἰατρική, καὶ τοῦ μετρίου ἐν τροφῇ μὲν ἰατρικὴ ἐν πόνοις δὲ γυμναστική.