Chapter 12.
140 There is then no doubt but that those things which the Father works, the Spirit works also. Nor does He work in accordance with a command, as he who hears in bodily fashion, but voluntarily, as being free in His own will, not the servant of the power of another. For He does not obey as being bidden, but as the giver He is the controller of His own gifts.
141. Consider meanwhile whether you can say that the Spirit effects all things which the Father effects; for you cannot deny that the Father effects those things which the Holy Spirit effects; otherwise the Father does not effect all things, if He effects not those things which the Spirit also effects. But if the Father also effects those things which the Spirit effects, since the Spirit divides His operations, according to His own will, you must of necessity say, either that what the Spirit divides He divides according to His own will, against the will of God the Father; or if you say that the Father wills the same that the Holy Spirit wills, you must of necessity confess the oneness of the divine will and operation, even if you do it unwillingly, and, if not with the heart, at least with the mouth.
142. But if the Holy Spirit is of one will and operation with God the Father, He is also of one substance, since the Creator is known by His works. So, then, it is the same Spirit, he says, the same Lord, the same God. And if you say Spirit, He is the same; and if you say Lord, He is the same; and if you say God, He is the same. Not the same, so that Himself is Father, Himself Son, Himself Spirit [one and the selfsame Person]; but because both the Father and the Son are the same Power. He is, then, the same in substance and in power, for there is not in the Godhead either the confusion of Sabellius nor the division of Arius, nor any earthly and bodily change.
Source: On the Holy Spirit (New Advent)