And yet this might not necessarily involve the conversion of the Trinity into a Quaternity. If... in Greek, spirit, instead of being neuter had been feminine, who can say that the Virgin Mary might not already have become an incarnation or humanization of the Holy Spirit?... And thus a dogmatic evolution would have been effected parallel to that of the divinization of Jesus, the Son, and his identification with the Word.

The Tragic Sense of Life (1913) - VIII : From God to God