I’m trying to puzzle out the meaning of the following paragraph from Bonhoeffer’s Discipleship (DBWE 4).
Fundamentally eliminating simple obedience introduces a principle of scripture foreign to the Gospel. According to it, in order to understand scripture, one first must have a key to interpreting it. But that key would not be the living Christ himself in judgment and grace, and using the key would not be according to the will of the living Holy Spirit alone. Rather, the key to scripture would be a general doctrine of grace, and we ourselves would decide its use. The problem of following Christ shows itself here to be a hermeneutical problem.Dietrich Bonhoeffer, Discipleship, ed. Martin Kuske et al., trans. Barbara Green and Reinhard Krauss, vol. 4, Dietrich Bonhoeffer Works (Minneapolis, MN: Fortress Press, 2003), 82.
Here, Bonhoeffer appears to be contrasting the “simple obedience” required by a “costly grace” approach with a “paradoxical obedience” required by a “cheap grace” approach. The latter approach makes “a general doctrine of grace,” and not “the living Christ himself,” the “principle of scripture” (Schriftprinzip). And this general doctrine of grace, used in this way, results in a Schriftprinzip that is “foreign to the Gospel.”
Here’s editorial footnote 19:
 Bonhoeffer felt that this subject was so important that he added an entry on “principle of scripture and discipleship” to his subject index for the 1937 edition of Discipleship. See also Bonhoeffer’s 1925 term paper, “Is There a Difference between Historical and Pneumatic Interpretation of Scripture, and What Is the Point of View of Dogmatics?” (DBW 9:305–23).Dietrich Bonhoeffer, Discipleship, ed. Martin Kuske et al., trans. Barbara Green and Reinhard Krauss, vol. 4, Dietrich Bonhoeffer Works (Minneapolis, MN: Fortress Press, 2003), 82n19.
Incidentally, that 1925 term paper is *very* interesting. I don’t have time/space to summarize it here, but consider the following mention of “principle of scripture.” Bonhoeffer writes:
The standard that must be preserved in the exegesis of scripture is handed to us along with the word that is the revelation and foundation of the Bible. This standard is taken from the Bible itself and is, as Luther noted, “what drives toward Christ.” What the content of revelation does not have is not canonical.8Dietrich Bonhoeffer, The Young Bonhoeffer: 1918–1927, ed. Hans Pfeifer et al., trans. Mary C. Nebelsick and Douglas W. Stott, vol. 9, Dietrich Bonhoeffer Works (Minneapolis, MN: Fortress Press, 2003), 297.
He then adds in a footnote (this is Bonhoeffer’s footnote, not the editors’):
8 Hereby we are criticizing Calvin’s Reformed principle of Scripture and its repristination by Barth, which places the concept of the canon above Luther’s individual statement. We know that Luther is taking a very bold step, but we also know that it is in the interest of Protestant faith for us to take it with him.Dietrich Bonhoeffer, The Young Bonhoeffer: 1918–1927, ed. Hans Pfeifer et al., trans. Mary C. Nebelsick and Douglas W. Stott, vol. 9, Dietrich Bonhoeffer Works (Minneapolis, MN: Fortress Press, 2003), 297n8.
(Footnote 90 there is not Bonhoeffer’s original, but the editors. They draw our attention to: “Barth, “Das Schriftprinzip,” 221ff. esp. 223.” This is: “Das Schriftprinzip der reformierten Kirche” (The scriptural principle in the Reformed church). Zwischen den Zeiten 3/3 (1925): 215–45.)
So far, so good. I think I’m tracking with Bonhoeffer, although I’m not sure whether or not this critique of a “principle of scripture” has anything to do with the critique in his 1925 seminar paper.
But, I’ve only quoted the first half of the paragraph in question from Discipleship!
But it should be clear to a Gospel-oriented hermeneutic that we cannot simply identify ourselves directly with those called by Jesus. Instead, those who are called in scripture themselves belong to the word of God and thus to the proclamation of the word. In preaching we hear not only Jesus’ answer to a disciple’s question, which could also be our own question. Rather, question and answer together must be proclaimed as the word of scripture. Simple obedience would be misunderstood hermeneutically if we were to act and follow as if we were contemporaries of the biblical disciples. But the Christ proclaimed to us in scripture is, through every word he says, the one whose gift of faith is granted only to the obedient, faith to the obedient alone. We cannot and may not go behind the word of scripture to the actual events. Instead, we are called to follow Christ by the entire word of scripture, simply because we do not intend to wish to violate scripture by legalistically applying a principle to it, even that of a doctrine of faith.Dietrich Bonhoeffer, Discipleship, ed. Martin Kuske et al., trans. Barbara Green and Reinhard Krauss, vol. 4, Dietrich Bonhoeffer Works (Minneapolis, MN: Fortress Press, 2003), 82.
Here’s editorial footnote 20:
 Tholuck preceded his interpretation of the so-called antitheses, Matt. 5:21–48, with “two hermeneutic canons” (i.e., rules of interpretation), “through neglect of which misunderstandings of a radical and practical nature have been occasioned. 1. In this section, as indeed everywhere, not the literal, but the spiritual, interpretation is the true one” (Commentary, 163). “2. Our Lord’s mode of address is that of the popular orator; … hence, we have no right to take the letter of what He says in a strict literal sense, and to press it unduly” (165). Both places are marked in Bonhoeffer’s copy. Bonhoeffer was thinking of such rules for “dealing with” the Sermon on the Mount (cf. below, page 181) when he wrote on October 24, 1936: “I hope to finish my book [Discipleship], and would really like to start writing a hermeneutics volume. It seems to me there is a huge deficit there” (DBW 14:257 [GS 1:47]).Dietrich Bonhoeffer, Discipleship, ed. Martin Kuske et al., trans. Barbara Green and Reinhard Krauss, vol. 4, Dietrich Bonhoeffer Works (Minneapolis, MN: Fortress Press, 2003), 82n20.
Taken out of context, I *think* I understand Bonhoeffer’s caution against placing ourselves too directly into the situation of Jesus’s original disciples. And this caution strikes me as significant, given Bonhoeffer’s penchant for moving rather immediately, let’s say, from the text to the present application of the text.
However, I *don’t* understand the connection between this caution and the warning against making a general doctrine of grace into a principle of scripture that’s foreign to the gospel. What does letting both the disciples’ questions and Jesus’s answers stand as the Word of God have to do with not making grace into a principle that we can then use to avoid simple obedience to Jesus’ commands?