Just as, by reasoning upward from what belongs to us, we came to know the Word in relation to the transcendent nature, in the same way we shall also be led to the conception of the Spirit, observing in our own nature certain shadows and imitations of the ineffable power. In us, however, spirit is the drawing in of air, something foreign that must be drawn into and sent out from the body for its constitution; and when the word is uttered, this becomes voice, making the power of the word manifest in itself. But with regard to the divine nature, it has been judged fitting to confess that there is a Spirit of God, just as it has been granted that there is a Word of God. For the Word of God ought not to be conceived as more deficient than our own word, as though ours were contemplated together with spirit while His were believed to be without Spirit.
Yet it is not fitting to think, by analogy with our breath, that something foreign flows into God from outside and becomes the Spirit in Him. Rather, just as when we hear of the Word of God we do not suppose the Word to be something without subsistence, nor something acquired through learning, nor something brought forth by voice, nor something dissolved after being uttered, nor subject to any other condition of the kind observed in our word, but instead understand Him as subsisting essentially, possessing will, active, and almighty—so also, when we have learned of the Spirit of God, who accompanies the Word and manifests His activity, we do not conceive Him as a breath of air. For the greatness of the divine power would be brought down to something low if the Spirit in God were understood by analogy with ours in that way. Rather, we understand Him as an essential power, contemplated in Himself in a distinctive hypostasis, incapable of being separated either from God, in whom He is, or from the Word of God, whom He accompanies; nor does He dissolve into nonexistence. Instead, like the Word of God, He exists according to hypostasis, possesses will, is self-moving and active, always chooses the good, and in every purpose has power that runs together with His will.