75 Since, then, the whole invisible creation (whose substance some rightly believe to be reasonable and incorporeal), with the exception of the Trinity, does not impart but acquires the grace of the Spirit, and does not share in it but receives it, the whole commonalty of creation is to be separated from association with the Holy Spirit. Let them then believe that the Holy Spirit is not a creature; or, if they think Him a creature, why do they associate Him with the Father? If they think Him a creature, why do they join Him with the Son of God? But if they do not think that He should be separated from the Father and the Son, they do not consider Him to be a creature, for where the sanctification is one the nature is one.
Source: On the Holy Spirit (New Advent)