While reading tonight, I came upon this paragraph where Vermigli disambiguates the term “spirit” and explains how it is used with reference to the third divine mode of being, and I thought that it deserved to be shared. Bold is mine.
Peter Martyr Vermigli, Early Witings: Creed, Scripture, Church, The Peter Martyr Library, vol. 1 (Di Gangi and McLelland, trans.; McLelland, ed.; Kirksville, MO: Sixteenth Century Journal Publishers, 1994), 54-55.
By “spirit” we usually mean invisible power which has strength to drive and to direct. Thus the winds are called spirits, and so also are the means by which the soul governs, moves, and operates the body. Such unseen powers, although enclosed in our physical frame, relate in a subtle and invisible way to the bodies in which they operate. Hence the same word has come to mean natures and essences divested of that frame, and naked. That is the case with God, the angelic choirs, and the deceased whose souls are already separated from their bodies. Thus the divine nature is called spirit. Christ plainly declared this in John’s Gospel, when he said that God is spirit and must be worshiped in spirit [Jn 4.23]. For that reason there is no difference between Father, Son, and Holy Spirit. In the final analysis the name “Holy Spirit” not only represents the divine nature, invisible and incorporeal, but indicates how the third person is distinct form the Father and the Son. His name, Holy Spirit, expresses his proper office: driving, moving, persuading, governing, consoling, illumining, and carrying out the work of sanctification effectively in the souls and hearts of believers. The saints know of these wonderful effects from personal experience. Not by the exercise of reason, nor through the human senses, are these blessings understood or made visible. Therefore it is not without reason we say that we believe in the Holy Spirit. Although he exceeds our natural capacities, we know him from what is set forth distinctly in the Scriptures.