7 The Father, the Son and the Holy Ghost alike hallow, quicken, enlighten, and comfort. No one will attribute a special and peculiar operation of hallowing to the operation of the Spirit, after hearing the Saviour in the Gospel saying to the Father about His disciples, sanctify them in Your name. In like manner all other operations are equally performed, in all who are worthy of them, by the Father and by the Son and by the Holy Ghost; every grace and virtue, guidance, life, consolation, change into the immortal, the passage into freedom and all other good things which come down to man.
Nay even the dispensation which is above us in relation to the creature considered both in regard to intelligence and sense, if indeed it is possible for any conjecture concerning what lies above us to be formed from what we know, is not constituted apart from the operation and power of the Holy Ghost, every individual sharing His help in proportion to the dignity and need of each. Truly the ordering and administration of beings above our nature is obscure to our perception; nevertheless any one, arguing from what is known to us, would find it more reasonable to conclude that the power of the Spirit operates even in those beings, than that He is excluded from the government of supramundane things.
So to assert is to advance a blasphemy bare and unsupported; it is to support absurdity on fallacy. On the other hand to agree that even the world beyond us is governed by the power of the Spirit, as well as by that of the Father and of the Son, is to advance a contention, supported on the plain testimony of what is seen in human life. Identity of operation in the case of Father and of Son and of Holy Ghost clearly proves invariability of nature. It follows that, even if the name of Godhead does signify nature, the community of essence proves that this title is very properly applied to the Holy Spirit.
Source: Letters (New Advent)