Padre Giovanni is less known; in fact I could only find a reference to him that is not taken from Thompson, in Italian. But it is interesting:
The Franciscan John of Cartagena (+1618) highlights that "this trinity of people has brought about our salvation: Jesus, as the author of salvation, Mary, as a mediator, Joseph, as a cooperator." (Google Translate)Il francescano Giovanni di Cartagena (+1618) mette in evidenza come “questa Trinità di persone ha operato la nostra redenzione: Gesù, come autore della salvezza; Maria, come mediatrice; Giuseppe, come cooperatore”.
So to him, there is (I assume) the Holy Trinity and then a "trinity of persons", that only shares one person with the Holy Trinity, Jesus, but is otherwise a group of three people.
I think that Thompson took the term "order of hypostatic union", originally meant to indicate a varying degree of proximity to Jesus, to mean an absolute, not relative, hypostatic union of Jesus Mary and Joseph. To say that Mary and Joseph enjoy a special closeness to Jesus is to speak the truth; to say that this puts the three in a hypostatic union qualitatively different from the beatific vision all the saints share, -- is heresy. Does Thompson actually say the latter is not clear, but at least it would had been incumbent on him to clarify this point.
I believe that the author of the quote was referring to what Eastern Christianity means by “theosis” or “deification,” this “conforming to the divine nature” of soken about in 2 Peter 1: 2-11.
The fault of our author here is not one of malice, but of ignorance, as he reached out to incorrect terminology in describing a very biblical facet of the Christian life in his enthusiasm and hurry in communicating it.
For the message remains urgent: theosis is the common call and norm of life for every Christian and not the exception. Christians are not called to be merely ethical, but HOLY, and holiness and SALVATION are tied to the practice of the Sermon of the Mount and, not to faith alone.
+JMJ,
-Theo
-Theo