I'm going to do a massive update on Aquinas today. He's working through the nature of the trinity, and this will mean that Calvin will get a pass. I've lost a few weeks, while Briggs metholdically goes through the passages. I will post extracts: read the whole things.
ON THE HOLY SPIRIT, THAT HE IS IN DIVINITY
1 Now, divine Scriptures’ authority not only tells us about the Father and the Son in divinity, but together with these two also numbers the Holy Spirit. For our Lord says: “Going, therefore, teach ye all nations: baptizing them in the name of the Father, and of the Son, and of the Holy Spirit” (Mat. 2.8:1g). And 1 John (5:7) says: “there are three who give testimony in heaven, the Father, the Word, and the Holy Ghost.” Sometimes, also, the procession of this Holy Spirit is mentioned by Scripture. We read in John (15:26): “When the Paraclete comes, whom I will send you from the Father, the Spirit of truth, who proceeds from the Father, He shall give testimony of Me.”
We need to note that the spirit descended on Saul, but then left him: it descended on David, and upon the judges before him and the prophets who confronted the king. But in this time, we are sent the spirit, not to some, but to all who are of Christ.
Aquinas in the remainder of that chapter (which I have not quoted) discusses various errors made by early heresairchs.
THAT THE HOLY SPIRIT IS TRUE GOD
1 One shows, of course, by clear testimonies from Scripture that the Holy Spirit is true God. For to none but God is a temple consecrated, and so the Psalmist speaks of “God in His holy temple” (Ps. 10:5). Yet there is a temple assigned to the Holy Spirit, for the Apostle says: “Or know you not that your members are the temple of the Holy Spirit?” The Holy Spirit, therefore, is God. This is especially clear since our members, which the Apostle calls the temple of the Holy Spirit, are the members of Christ. For just above he had set down: “Know you not that your bodies are the members of Christ?” (1 Cor. 6:19, 15). It obviously would be awkward (since Christ is true God, as is clear from the foregoing) to have the members of Christ a temple of the Holy Spirit if the Holy Spirit were not God.
2 Again, holy men do not give the cult of adoration except to the true God, for Deuteronomy (6:13) says: “You shall fear the Lord your God, and shall serve Him only.” But holy men serve the Holy Spirit, as the Apostle says: “We are the circumcision who serve the Spirit of God” (Phil. 3:3). And although some books have “who serve in the spirit of the Lord,” the Greek books and some Of the more ancient Latin ones have: “who serve the Spirit of God.” And from the Greek itself, this clearly must be understood as the cult of adoration which is due to God alone. Therefore, the Holy Spirit is true God to whom adoration is due.
3 Further, to sanctify men is the proper work of God, for Leviticus (22:32) says: “I am the Lord who sanctify you.” It is, of course, the Holy Spirit who sanctifies, as the Apostle says: “You are washed, you are sanctified, you are justified in the name of our Lord Jesus Christ, and the Spirit of our God” (1 Cor. 6:11). And in 2 Thessalonians (2:12) one reads: “God has chosen you first fruits unto salvation, in sanctification of the Spirit and faith of the truth.” Necessarily, therefore, the Holy Spirit is God.
4 And further, just as the life of corporeal nature is from the soul, so the life of justice of the soul itself is from God; and so our Lord says: “As the living Father has sent Me, and I live by the Father, so He that eats Me, the same also shall live by Me” (John 6:58). Of course, this kind of life is from the Holy Spirit, and so our Lord adds in the same place: “It is the Spirit that gives life” (John 6:54); and the Apostle says: “If by the Spirit you mortify the deeds of the flesh, you shall live” (Rom. 8:13). Therefore, the Holy Spirit is of the divine nature.
I think the reader should note that Calvin sits squarely in the middle of an intellectual/theological tradition that goes through Aquinas to Augustine to the early fathers to Christ. There is not a sense in which we are able to sanctify ourselves. Any good that happens to us is of God, and any move we do for good is the Spirit of God working in us.
THAT THE HOLY SPIRIT IS A SUBSISTENT PERSON
1 But, since some assert that the Holy Spirit is not a subsistent person, but, rather, the divinity of the Father and the Son (so some Macedonians are held to have said); or even an accidental perfection of the mind bestowed on us by God—wisdom, for instance, or charity or something of this sort (and these are participated by us as certain created accidents); one must on the contrary show that the Holy Spirit is nothing of this kind.
2 For accidental forms have no proper operations; instead, one has them in accord with the decision of his will, for the wise man uses wisdom when he wills. But the Holy Spirit operates in accord with the decision of His will. This has been shown. One must not, therefore, think of the Holy Spirit as an accidental perfection of the mind.
3 The Holy Spirit, again, so we are taught by Scripture, is the cause of all the perfections of the human mind. For the Apostle says: “The charity of God is poured forth in our hearts, by the Holy Spirit, who is given to us” (Rom. 5:5)” and: “To one indeed, by the Spirit, is given the word of wisdom, and to another, the word of knowledge, according to the same Spirit” (1 Cor. 12:8), and so of the rest. The Holy Spirit, therefore, must not be thought of as an accidental perfection of the human mind, since He is, of all perfections of this kind, the existing cause.
4 Of course, that in the name of the Holy Spirit the essence Of the Father and Son is designated so as to be personally distinguished from neither of them conflicts with what divine Scripture hands on to us about the Holy Spirit. It says that the Holy Spirit “proceeds from the Father” and that He receives from the Son (John 15:26; 16:14). And this cannot be understood of the divine essence, since the divine essence neither proceeds from the Father nor receives from the Son. One must, then, say that the Holy Spirit is a subsisting Person.
Briggs notes that we are some chapters from "filoque" which led to the split between the west and eastern churches. Calvinists resist speculation here. So should we. The spirt is God, is fully God, and was sent to us. We all have the power of the prophets and apostles of old living with us. Let's not contemplate the nature of the mass, (transubstantion, consubstantation or symbolic remembrance) and consider that we are the temple of the Holy Spirit. God lives within us, and we do his work.
That is beyond understanding.