The most comprehensive critique of the Finnish school of Luther interpretation available in English is the volume of William Schumacher titled, Who Do I Say That You Are? Anthropology and the Theology of Theosis in the Finnish School of Tuomo Mannermaa. Arguing from an anthropological perspective, Schumacher argues that the Finnish school has misinterpreted Luther's theology, replacing Luther's theology of the word with an ontologically focused approach to the human person. For Schumacher's Luther it is God's word of address to the sinner, as a creative word, which has primacy. This is distinguished from Finnish writers who propose that the human creature is defined by ontological union with God.
For Schumacher, the traditional Lutheran approach to justification and Mannermaa's school are incompatible with one another. Justification is either theosis (Mannermaa) or forensic (the Book of Concord). Thus Mannermaa's approach to justification is essentially an attack on the entire Lutheran tradition after the Osiandrian controversy. Schumacher purports that the Finnish school is "if not a complete rehabilitation of Osiander, then at least the attempt to salvage key elements of his system which has been previously rejected by the Lutheranism of the Formula of Concord."(91) Schumacher points out that the Osiandrian error involved more than a denial of the unity of Christ's two natures, but also the prioritizing of the incarnation of Christ over his death and resurrection, leaving the cross in a subsidiary position. I think Schumacher's argument here is partially correct. There is an overemphasis in many of the Finnish writers on the incarnation, which makes salvation primarily an ontological reality, displacing the objective event of the cross. I don't think the solution to this problem is to reject ontological categories, and the soteriological significance of the incarnation as Schumacher does, but is to have a balanced approach to the soteriological significance of all events in Christ's life. In Lutheran soteriology (along with that of Paul), the cross is always the central salvific event. I think a more balanced approach would be to take the Finnish theology of incarnation, and place it within the context of the Formula's forensic emphasis. While the forensic elements of salvation may be primary, there are also strong ontological themes in Luther's thought which need not be neglected.
One of the problems with Schumacher's contention that the Finnish school is essentially Osiandrian is that he fails to discuss the primary problems with Osiander's theology according to the Formula of Concord. The Formula isn't condemning the concept of ontological union, or the importance of Christ's indwelling; rather, the Formula is seeking to clarify that the infusion of love and other virtues does not precede justification. In other words, the concern of the Formula is salvation by works, not the idea that Christ is present in faith. I think the problem here begins with the Finnish interpretation who conclude that the Formula is opposed to Luther. I don't think such a division exists. Luther places salvation in both juridical and participationist categories. The Formula focuses on the forensic elements (rightly so I think) because of the necessity of clarifying these issues in light of Osiander's teaching. This shouldn't be pitted against Luther's own theology, when Luther was willing to approve of Melancthon's writings on justification with primarily (at times exclusively) forensic language.
The most interesting chapter in Schumacher's work is in his evaluation of Luther's own writings. Schumacher rightly points out that the Finnish school tends to conflate the early and late Luther, ignoring the development of Luther's thought, especially his great Reformation discovery. It is somewhat surprising that one of the most significant passages for the Finnish school comes from a Christmas sermon in 1514, when Luther hadn't yet developed his mature understanding of justification. In some of the more extreme forms of the Finnish approach (Karkkainen for example), the Reformation discovery is almost completely ignored, and one wonders why the Medieval church would even have an issue with Luther's view of justification if this interpretation were correct. Here is where I think Schumacher paints with too broad a brush. While many in this school ignore the categories of imputation, and even sola fide, Mannermaa is careful to place these categories in the context of Luther's overall thought, though I do agree that he downplays their importance. This chapter demonstrates that some of the language used by the Finnish school doesn't mean what they claim in the context of Luther's own writings. However, I remain convinced of the central thesis of Mannermaa that Luther teaches that an ontological union with Christ is the metaphysical basis for God's gracious imputation. In otherwords, Christ is truly present in faith, giving himself to the Christian as righteousness, especially through the debt paid on the cross and Christ's victory over the devil according to both natures; this does not neglect the fact that the union of God and man in the incarnation is also a necessary part of the Christian's righteousness. (Regarding the so-called "active obedience" of Christ, I don't find this theme in Luther, though I personally do affirm its validity).
One of my primary areas of interest, especially as I dealt with this topic in my book The Righteousness of One: An Evaluation of Early Patristic Soteriology in Light of the New Perspective on Paul, is in the connection between Luther's theology and that of the Church fathers. Schumacher convincingly demonstrates that the influence of the Greek fathers on Luther has been overstated by the Finnish school. Luther's primary influences, rather, were Augustine, Ambrose, Jerome, Bernard, and the German mystical tradition. He correctly points out that deification language in Luther is taken from medieval mysticism, and is thus not identical with Eastern conceptions of theosis. I would point out, however, that there are many commonalities between the mystical tradition which Luther praises and the Eastern fathers. Whether the Eastern fathers had any significant influence on Bernard, Tauler, or the Theologia Germanica remains to be demonstrated, but one cannot help seeing certain common themes. The Theologia Germanica, for example, states: “God assumed human nature or humanity. He
became humanized and man became divinized. That is the way amends were made." (The Theologia Germanica of Martin Luther, 63) It seems unthinkable to me that Luther would promote and publish the Theologia Germanica and the works of Tauler throughout his life if he didn't agree with their conviction that salvation is in some sense an ontological event.
Schumacher's book is a fascinating read, and is essential to grapple with for any interested in this issue. Schumacher points out some of the genuine flaws in Finnish Luther research, which often lets an ecumenical agenda guide research, rather than letting the evidence speak for itself. However, in doing this, Shumacher swings too far in the other direction, ignoring the ontological soteriological concepts that are prominent in such works as "On Christian Liberty", "Two Kinds of Righteousness", and the 1535 Galatians commentary. The fact that Luther could promote both Melancthon's works which deal almost exclusively in legal categories, and the Theologia Germanica which deals almost exclusively in ontological categories should show us that both sides in this debate have often set up a false dichotomy which was foreign to Luther.