At some level all trained theologians with an ounce of the historian in their blood (and only theologians with quite a bit more than an ounce of it are worth paying close attention to…) know that the vast majority of what gets said on this score is exaggeration, generalization, and stereotype. But we do it anyway. Why? Answering that question is one of the purposes of Christine Helmer’s article, “Luther and Calvin in Modern Protestant Theology” (in Hooker, ed., Calvin and Luther: The Continuing Relationship [V&R, 2013]). Here is how she sets up some of the ways that Luther and Calvin are often pitted against each other:
The contemporary divide, in at least the rhetoric, between Luther and Calvin is the division between them in terms of the preferred genre for theological writing. Luther is cast as an “occasional writer.” The evidence for this designation is that he wrote generally on an ad hoc basis, right in the midst of controversy, hastily composing outrageous responses to diatribes maliciously direct against him. Calvin in contrast is the “systematician.” He presented the edifice of Christian doctrines in a systematic form: The Institutes of the Christian Religion are neatly divided into four major sections, devoted to each person of the Trinity with a fourth division assigned to the church. The formal structure is then cross-divided in terms of content by the conceptual distinction between God the Creator and the Redeemer.
The difference in genre could be attributed to a difference in personality. Calvin tends to be represented as the cool one on the temperature scale . . ., while Luther is hot-blooded and hot-tempered. Calvin is the eminent Frenchman, an émigré to Switzerland, who represents the haute culture of his native land, while Luther embodies all the uncultured traits of a German peasant, from drunken mealtimes to scatological outbursts. Calvin is requested to gleefully return to Geneva, while Luther throws himself into controversy with reckless abandon, burning bridges. Calvin sets up laws that govern Christian behavior; Luther counts on an instinctual ethics based on the spontaneity that love’s indwelling in the heart causes. The choice of genre that represents one’s theology can thus be taken in the psychological terms that language expresses personality. The system privileges rationality and is identified with the one who betrays sovereign gravitas; occasional writing is correlated with one who is not master of his emotions, someone who is insufficiently differentiated from context, and can only react, not choose to act. (210–211)
All of this should be recognizable from intro to systematic or historical theology courses. The great thing about Helmer’s piece is that she immediately pivots (esp. on p. 212) and starts deconstructing this picture. For instance: Luther was trained in medieval scholastic theology, wrote a commentary on Lombard’s sentences, and functioned comfortably within the disputation. (Helmer even suggests that calumnies about Luther’s allegedly unsystematic work masks a polemic against the Roman Catholic scholasticism in which he was trained.) On the other hand: Calvin was trained as a humanist with textual rather than systematic emphasis, was a lawyer skilled in application of reason to particular issues, and close inspection of the Institutes reveals that its apparent systematicity is “a pretense.” The work “is a palimpsest, not a system.” So again, the question is: Why do we think about Luther and Calvin in these stereotypical ways?
It is not enough to blame Reformed polemics against Lutheranism. Why? Helmer doesn’t say so, but it is unthinkable that this would emerge in the 16th century. Calvin said too many nice things about Luther. (That said, the Reformed tradition is not reducible to Calvin and many of the not-Calvins at the head of the tradition had poor opinions of Luther, so there may be room for further investigation here.) Helmer does say that it can’t be the 17th century's fault because both Lutheran and Reformed theologians in that period valued and produced systems. Similarly in the 19th century: you have both Schleiermacher and Hegel and while they weren’t happy with each other, you can’t credibly accuse one or the other of not being systematic.
So, how are we to answer the “Why” question? I don’t want to steal Helmer’s thunder, but she finds the answer in the 20th century.
*cue dramatic music
Go read the essay.