τὸν στερεοῦντα τὸ πνεῦμα.  It is to be noticed here that St. Basil uses the masculine and more personal form in apposition with the neuter πνεῦμα, and not the neuter as in the creed of Constantinople, τὸ κύριον καὶ τὸ Ζωοποιὸν τὸ ἐκ τοῦ πατρὸς ἐκπορευόμενον, etc.  There is scriptural authority for the masculine in the “ὅταν δὲ ἔλθῃ ἐκεῖνος, τὸ πνεῦμα τῆς ἀληθείας” of John xvi. 13.  cf. p. 15–17.