This work will be especially helpful to you if you are studying texts that date back to the time when it was normal for Americans to have had Latin in high school and that would include such worsks as Karl Barth's 16 volume "Church Dogmatics" where the Latin goes untranslated in the older translation of his Dogmatics. Muller's personal interest is primarily scholastic Calvinism, but the theological terms interpreted and explained here are helpful to anyone studying the Reformation, classic dogmatics, or the Reformers' interaction with late medieval scholastics and the terms normal for the Reformation debate. As one previous reviewer noted, the term "media gratiae" is interpreted as means of grace by both the Reformed and the Lutherans, but that the Lutherans use the stronger term "media salutis" (means of salvation) when speaking of the sacraments. The reason is that salvation is exclusively tied to the Word and the 2 Gospel sacraments in Lutheranism whereas Calvin and Zwingli always allowed for independent action of the Spirit outside of the 2 sacraments in particular. Another good example of Muller's fairness to other traditions is his description of "consubstantio." Muller points out that "consubstantion" is not the appropriate term to describe Luther's understanding of "real presence" in the Lord's Supper. The term was mistakenly given to Lutherans by the Reformed, but it is incorrect since Luther's understanding of Christ's presence in the eucharist is a sacramental union of Christ's body with the bread and wine and not a local presence. Those are just two examples and any student of the church fathers will benefit from Muller's explanation of terms such as "persona," "ousia," "substantia," etc. in relation to the early Church's understanding of the trinity (mia ousia, treis hypostaseis) and the two natures (naturas) in the person (persona) of Christ. Overall an exceptionally helpful resource for Protestants.