In his analysis of Luther’s treatment of Galatians (in Reformation Readings of Paul), David Fink gives a brief overview of pre-Reformation interpretations of the letter.
Jerome said that the letter “is concerned especially with establishing the ‘cessation of the old Law and the introduction of the new Law.'” Jerome sees the relation as one of promise and fulfillment, “whereby the fullness of evangelical grace renders obsolete the burdens of Jewish custom” (34).
In contrast to Romans, which addresses Jews who are clinging to old customs, Galatians focuses on “Gentile converts who had been intimidated into observing Jewish practices by the authority of ‘certain people who claimed that Peter, James and all the churches of Judea were conflating the Gospel of Christ with the old law'” (34). Paul’s response is a “middle course than neither betrays the gospel nor undermines “his [Jewish] forefathers” (34).
In short, “For Jerome . . . the letter to the Galatians must be read as addressing a very specific historical context, and Paul’s rhetoric must be interpreted accordingly. The letter does not set out a straightforward description of universal theological themes in the manner of a philosophical treatise; rather it ‘makes a stealthy approach, as if going by a secret passageway'” (34).
Other early writers – Fink mentions Augustine – universalized the letter into a treatise on law and faith as “complementary movements within God’s overarching economy of grace” (35).
Yet Jerome’s more historically grounded reading – let us call it the JPP, Jerome’s Perspective on Paul – continued to have advocates throughout the medieval period. The NPP isn’t so much a new perspective as the recovery of emphases that have been percolating in the church for centuries.