Warfield notes two discussions of the Didache which he thinks could bear further examination based on their results and methods, in particular reference to the Two Ways material (Warfield 1886, 81). Dr. Bratke, writing in Jahrbücher für protestantich Theologie (1886, i. 302-31) takes the Didache as an old example of the “Two Ways” material taken from a Latin version (Warfield 1886, 82). Warfield is not certain that the borrowing as described by Bratke is entirely the case, but that, at least in general terms, he is correct. Warfield does recognize that, in the absence of complete evidence, it is not possible to have absolute certainty about what document influenced what others (Warfield 1886, 84).
Warfield refers to the work of a Dr. McGiffert, who considers the existence of a common source of the Two Ways material, influencing both the Didache and the Epistle of Barnabas (Warfield 1886, 84). McGiffert assumes an influence from Baranabas on a Latin version later used by Lactantius. Warfield does not think an adequate case for this can ever be built (Warfield 1886, 85). The underlying issue is whether one can prove a source of particular arrangements of ideas. Warfield gives examples of argument from absence, which are not persuasive (Warfield 1886, 87).
Warfield next turns to the suggestion that the original Two Ways omitted much of i.3-ii.1, as well as the possibility that chapter vi. is not original (Warfield 1886, 89). The omission of these passages in Barnabas, while they are present in other witnesses, suggests that Barnabas was drawing on different source material (Warfield 1886, 90).
Quotations of the Didache by various authors further suggest to Warfield that the authors had different versions of the material, some with or without various features. Further, estimates of the size of the Didache vary in authors who comment on its size (Warfield 1886, 92). Yet among these different versions Warfield observes that where “chapters i.-vi. are known, something from the latter part of the Didache seems to be known also” (Warfield 1886, 93). Other portions are either quoted or alluded to. Warfield documents these allusions in numerous different authors (Warfield 1886, 95).