The Holy Spirit is in a way the most mysterious of the three "names" of God. For many it is the "unknown God" (Acts 17:23). How can a "Spirit" be love? How can it be a person? What role can a "Spirit" have in the trinitarian relations?
In The Breath of God, Veto argues that a more exact comprehension of the third divine person can be reached by considering the way it acts in the economy of salvation and how it reveals itself in its scriptural names: Ruah and Pneuma, breath or wind. Just as, in the eternal life of God, the Father and the Son are precisely what their names designate, likewise, the Holy Spirit is the Breath of God. The procession of the Spirit is the "breathing out" of the Father into the Son, the communication of one intimacy into another, and the "breathing" back of the Son into the Father.
This leads to reshaping many aspects of trinitarian theology, in particular divine personhood. It is also fruitful for the believer's life of prayer because it offers a better understanding of the distinct relationship one can have to Father, Son, and Spirit.