The doctrine of the W. Church that the Holy Spirit proceeds from the Father and the Son. Against it E. theologians have urged that there must be a single Fount of Divinity in the Godhead; they hold that the Holy Spirit proceeds from the Father ‘through the Son’. W. theologians argue that as both Latins and Greeks hold everything common to the Father and the Son except the relationship of Paternity and Sonship, the Spiration of the Holy Spirit, in which this relation is not involved, must be common to both. The question did not become a matter of controversy between the E. and W. Churches until the time of Photius (864); it was one of the chief points of difficulty at the Council of Florence. See also Filioque.