I've been reading a bit of Augustine of Hippo recently, the great Doctor of the western Church of late antiquity. The more I read his descriptions of the Holy Spirit, the more I see why the filioque arose from such thinking. He says it was the common spirit of the Father and Son, suggesting it seems to be proceeding forth from both, 'breathed' on the disciples by Jesus as much as from the Father, in his writings.
For instance:
"Wherefore, when our Lord breathed on His disciples and said, Receive the Holy Ghost, He certainly wished it to be understood that the Holy Ghost was not only the Spirit of the Father, but of the only begotten Son Himself. For the same Spirit is, indeed, the Spirit of the Father and of the Son, making with them the trinity of Father, Son, and Spirit, not a creature, but the Creator. For neither was that material breath which proceeded from the mouth of His flesh the very substance and nature of the Holy Spirit, but rather the intimation, as I said, that the Holy Spirit was common to the Father and to the Son; for they have not each a separate Spirit, but both one and the same. Now this Spirit is always spoken of in sacred Scripture by the Greek word πνεῦμα, as the Lord, too, named Him in the place cited when He gave Him to His disciples, and intimated the gift by the breathing of His lips; and there does not occur to me any place in the whole Scriptures where He is otherwise named." - Book XIII, City of God.
"But, whether the Holy Spirit of the Fatber, and of the Son, who are both good, can be with propriety called the goodness of both, because He is common to both, I do not presume to determine hastily. Nevertheless, I would have less hesitation in saying that He is the holiness of both, not as if He were a divine attribute merely, but Himself also the divine substance, and the third person in the Trinity. I am the rather emboldened to make this statement, because, though the Father is a spirit, and the Son a spirit, and the Father holy, and the Son holy, yet the third person is distinctively called the Holy Spirit, as if He were the substantial holiness consubstantial with the other two. But if the divine goodness is nothing else than the divine holiness, then certainly it is a reasonable studiousness, and not presumptuous intrusion, to inquire whether the same Trinity be not hinted at in an enigmatical mode of speech, by which our inquiry is stimulated, when it is written who made each creature, and by what means, and why. For it is the Father of the Word who said, Let there be. And that which was made when He spoke was certainly made by means of the Word. And by the words, God saw that it was good, it is sufficiently intimated that God made what was made not from any necessity, nor for the sake of supplying any want, but solely from His own goodness, i.e., because it was good. And this is stated after the creation had taken place, that there might be no doubt that the thing made satisfied the goodness on account of which it was made. And if we are right in understanding; that this goodness is the Holy Spirit, then the whole Trinity is revealed to us in the creation." - Book XI, City of God.
It looks like the Western conception of the Trinity had filioque incipient to it, since at least late antiquity.
For instance:
"Wherefore, when our Lord breathed on His disciples and said, Receive the Holy Ghost, He certainly wished it to be understood that the Holy Ghost was not only the Spirit of the Father, but of the only begotten Son Himself. For the same Spirit is, indeed, the Spirit of the Father and of the Son, making with them the trinity of Father, Son, and Spirit, not a creature, but the Creator. For neither was that material breath which proceeded from the mouth of His flesh the very substance and nature of the Holy Spirit, but rather the intimation, as I said, that the Holy Spirit was common to the Father and to the Son; for they have not each a separate Spirit, but both one and the same. Now this Spirit is always spoken of in sacred Scripture by the Greek word πνεῦμα, as the Lord, too, named Him in the place cited when He gave Him to His disciples, and intimated the gift by the breathing of His lips; and there does not occur to me any place in the whole Scriptures where He is otherwise named." - Book XIII, City of God.
"But, whether the Holy Spirit of the Fatber, and of the Son, who are both good, can be with propriety called the goodness of both, because He is common to both, I do not presume to determine hastily. Nevertheless, I would have less hesitation in saying that He is the holiness of both, not as if He were a divine attribute merely, but Himself also the divine substance, and the third person in the Trinity. I am the rather emboldened to make this statement, because, though the Father is a spirit, and the Son a spirit, and the Father holy, and the Son holy, yet the third person is distinctively called the Holy Spirit, as if He were the substantial holiness consubstantial with the other two. But if the divine goodness is nothing else than the divine holiness, then certainly it is a reasonable studiousness, and not presumptuous intrusion, to inquire whether the same Trinity be not hinted at in an enigmatical mode of speech, by which our inquiry is stimulated, when it is written who made each creature, and by what means, and why. For it is the Father of the Word who said, Let there be. And that which was made when He spoke was certainly made by means of the Word. And by the words, God saw that it was good, it is sufficiently intimated that God made what was made not from any necessity, nor for the sake of supplying any want, but solely from His own goodness, i.e., because it was good. And this is stated after the creation had taken place, that there might be no doubt that the thing made satisfied the goodness on account of which it was made. And if we are right in understanding; that this goodness is the Holy Spirit, then the whole Trinity is revealed to us in the creation." - Book XI, City of God.
It looks like the Western conception of the Trinity had filioque incipient to it, since at least late antiquity.
