Having previously posted about the controversy about Rabbi Dr. David Zvi Hoffmann's thesis Mar Samuel (and, really, his approach to his non-biblical and non-halakhic* studies of Judaism), I thought it worthwhile to quote a selection from David Ellenson's book Rabbi Esriel Hildesheimer and the Creation of a Modern Jewish Orthodoxy:
What, however, was the nature of Hoffmann's scholarship in his other major field of academic study, rabbinics, which Hirsch had labeled "heretical"? In examining this area of Hoffmann's academic work, it is clear that some of the same patterns evident in his biblical studies are present here, too. In nearly all of his works, the same, seemingly obligatory statements about the nature of authentic Jewish faith are found. In his rabbinic investigations, in contrast to his biblical studies, however, Hoffmann appears to be more of the contemporary academic. Throughout his works he cites the scholarship of Rappoport, Frankel, Geiger, and Graetz, sometimes approvingly, sometimes disapprovingly--but never, it seems, tendentiously. In this way, Hoffmann becomes one among several academic scholars involved in a community of research. In addition, Hoffmann often employs an approach to the field of rabbinic history which marks him as a practitioner of Religions-Wissenschaft in the broadest cultural sense, an approach that allowed him to consider the ways in which the surrounding culture of the ancient Near East may have influenced rabbinic civilization, something he would never have considered doing in his biblical studies. For example, in his Mar Samuel, Hoffmann points out that the rabbis were identified as Hachamim, "Weise." Then, in a footnote, he states, "One also designated the Savants of other peoples with the selfsame title." It was remarks such as this, along with his citation of "heretics" such as Graetz and Frankel, which undoubtedly aroused the ire of Orthodox colleagues like Hirsch and caused them to view at least this work of Hoffmann as kefirah, heresy.
Hoffmann's writings on the evolution of the literary structures, forms, terminology, and modes of interpretation in both midrash and Mishnah would seemingly be even more dangerous to the foundations of Orthodox Jewish faith. Yet there is no question that Hoffmann did investigate these texts in a manner that makes it difficult to distinguish him from Frankel, Geiger, or other scholars of rabbinic literature. This does not mean that Hoffmann agreed with them either on particular points or specific theories. But Hoffmann was clearly involved in discourse with these men. Like Frankel Darkhe HaMishnah, Hoffmann First Mishna reveals that he saw development and variety in the different strata of mishnaic literature. His notion that there was a "First Mishna" before the destruction of the Second Temple and that there were disagreements among the later tannaim as to its form; his efforts to reconstruct and discover that form; his willingness to investigate the disparate strata which undergirded that form; as well as his work on the halakhic midrashim, all combine to reveal the seminal nature of his studies in the academic area of rabbinics. Proactive as opposed to reactive, his scholarship in this area is clearly distinct from his efforts in the discipline of Bible.
* I mean not relating to halakhah, rather than against halakhah!