Written as a response to Erasmus’ De Libero Abitrio Diatribe Seu Collatio, in which Erasmus critiqued Luther’s position on “absolute necessity” of the human will, Luther’s De Servo Arbitrio offers both a rebuttal of Erasmus’ position on the freedom of the human will as well as demonstrating Luther’s fullest explanation of his theological anthropology concerning the bound human will. As much has been written on this topic, our purpose here does not include considerations of Luther’s arguments concerning the will, instead focusing on his use of scripture, authority, and canon in the construction of his argument. Luther spends a good portion of this voluminous work responding to Erasmus from a general position of reason and Christian history, though without directly appealing to any sources apart from the occasional scripture (Luther, 101-109).
Of specific concern for Luther was Erasmus’ claim that scripture was not entirely clear at all points, which he blasted with appeals to a variety of scriptural texts (Luther, 109-112). Luther wrote that, “of course, that there are many texts in the Scriptures that are obscure and abstruse, not because of the majesty of their subject matter, but because of our ignorance of their vocabulary and grammar; but these texts in no way hinder a knowledge of all the subject matter in Scripture” thereby arguing that ambiguous interpretive matters in no way hindered claims to the overall clarity of scripture (Luther, 110). In parts of his work Luther seems to allow something of an appeal to philosophical inquiry, though he ultimately subjects all such thinking to scripture and rejects in its entirety the arguments of the medieval scholastics (Luther, 113-24). Perhaps most ambiguous in his use of authority remains Luther’s self stylization as a “seer” and his perspective on miracles (Luther, 130). Luther remains strangely silent as to the implications of what he seems to label as the gift of prophecy, leaving questions concerning the authority that he attributed to such a perspective unanswered. Additionally, in commenting on Erasmus’ perspective, Luther seems to concede the topic of miracles to the Catholic Church, noting that the Evangelical movement had no evidence of miraculous signs whereas the Church Fathers and saints had demonstrated ample evidence of miraculous events (Luther, 144-7). Though in this argument Luther seems to cut himself off from Apostolic Tradition, he does attempt to co-opt miracles for his position, arguing that no one has committed a miracle has done so on their own (Luther, 147-8). Throughout his discussion of the miraculous, Luther begs the question concerning the veracity of miraculous signs as evidence of authority, failing to adequately address the issue. At best, this seems to be a rhetorical approach conceding that miracles are not necessarily signs of God’s approval of the church.
As one would expect, throughout this work Luther primarily appealed to the scriptures, often labeled by him as the Word of God, for the ultimate guide for truth and doctrine, especially over against the opinions of others (Luther, 132). These appeals to scripture were, similar to Erasmus, typically undertaken in a manner now referred to as proof texting, with Luther making appeals to the theological content and grammar of the immediate context of a word of passage without considering its wider implications in the socio-historical context of the writing. As he conceived of the relationship between faith, the scriptures, and certainty as a rather close one, Luther argued that faith should be secure because of the clear meaning of scripture (Luther, 138). For Luther, the clearness and certainty of the passages of scripture pertaining to matters of the will and salvation are ultimately reinforced by the experience of conscience, which testifies to correct interpretation of scripture (Luther, 139-149). Cast in the light of the authority granted clear scriptural understanding and the confirmation of experience, Luther’s rejection of philosophical considerations and the perspectives of the church fathers makes more sense (Luther, 150-4). While arguing that the church fathers were but men and therefore prone to erring in matters of faith and doctrine, Luther argued that the truth church would never have truth of scripture hidden from them, reinforcing his understanding of scripture as the locus of Christian truth and authority (Luther, 154-8). Interestingly, Luther did little by way of Erasmus’ critique of sola scriptura as an individual reading except to critic Erasmus’ use of the church fathers and medieval scholastics. Of further interest, Luther apparently agreed with Erasmus on the parameters of their discussion, noting that the issue was not what materials constitute authoritative scripture, but instead the meaning of scripture (Luther, 158). Such an admission remains intriguing, as Erasmus appealed to the apocryphal Wisdom of Sirach as a source arguing for free will, a source that Luther ultimately seems to have rejected along with the rest of the Old Testament Apocrypha, though he gives no such indication of this position in his argument against Erasmus in De Servo Arbitrio.
In his critique of Erasmus’ scriptural arguments for free choice, Luther appealed primarily to scripture and what one would assumed he would have termed as ‘plain reason,’ drawing primarily upon the writings of Paul and John (Luther, 161-219). Notable here is Luther’s section critiquing Erasmus’ failure to recognize the categories of Law and Gospel within the scriptures (Luther, 194-200). Similarly, in his sections concerning the formation of arguments against free choice and offering a critique of Erasmus’ section on his Assertio, Luther again appealed primarily to scriptures as his source of authoritative critique, though he occasionally referenced lessons and interpretations from church history (Luther, 219-292). Luther’s final section involves his use of additional scriptural interpretations, especially from the writings of Paul and John, and his further rejection of any insights from the medieval scholastics (Luther, 292-334). To conclude Luther’s perspective on scripture and authority here, it seems beneficial to include this portion of his views concerning interpretation, in which he argues that no inferences are acceptable “in any passage of scripture, unless it is forced on us by the evident nature of the context and the absurdity of the literal sense as conflicting with one or another of the artifacts of faith. Instead, we must everywhere stick to the simple, pure, and natural sense of the words that accords with the rules of grammar and the normal use of language as God created it in man” (Luther, 221). From Luther’s perspective in De Servo Arbitrio, however, the clearly understood writings of the Christian canon, especially those found within the paradigm of Gospel, were alone to be the ultimate sources of authority for the Christian church.
 Here, Luther both reviews Erasmus’ work as well as offers his understanding of the human will, namely its bondage to sin and lack of free will in matters of salvation. Luther offers a variety of arguments, the vast majority of which come from the both testaments of Christian scripture. This works is incredibly extensive, and thus for the purposes of this work the contents have been treated in a rather summary manner.
 Also known as Ecclesiasticus, as it is called by both Luther and Erasmus.
 From our position, especially in reading through Erasmus, it seems highly dubious as best to accept Luther’s claim that sola scriptura remains the sole authority for church practice, especially in light of more recent arguments concerning the agency and authority of texts within community (see Dale Martin’s Sex and the Single Savior). While Luther may have characterized his position as advocating sola scriptura, it seems more accurate to label his position as “Luther’s interpretation of scripture,” as all reading of scripture involves interpretation, and thus scriptures cannot effectually stand on their own as authoritative.