Four trends in Jewish scholarship in the early nineteenth century, as described by R. Jacob Shachter in his introduction to R. Zevi Hirsch Chajes, The Students' Guide Through The Talmud, pp. xxi-xxiii:
During the early part of the nineteenth century the leaders of Jewish thought divided themselves into two, three, or even four different groups. The leading spirits of the great majority such as Rabbis Landau, Banett, Eiger and Sofer, were permeated with the belief in the basic dogma of Torah Min Ha-Shamayim, i.e. that both the Written and the Oral Law were divinely revealed. As far as they were concerned this belief was based on such an abundance of convincing evidence as to be no mere opinion, and no efforts of faith, therefore, were needed for its acceptance. The trend of thought diametrically opposed to the above was led by Geiger, Holdheim, Einhorn, and Mannheimer, who initiated a campaign which tended utterly to deny the binding authority of the Oral Law, and consequently to discard several of its vital precepts. Besides these two groups, however, another movement arose whose protagonists, such as Zunz, Krochmal, Rappaport, and Frankel, aimed at steering a middle course. Whilst they were determined one the one hand to resist the negation of historic Judaism, they advocated, on the other hand, freedom of thought and the expression of critical opinions, declaring the Halacha in general to be the product of a long process of development, in the course of which elements from a variety of sources had been absorbed into the body of Judaism, and so tacitly admitted the desirability of changes in traditional Judaism. Thus, whilst the leaders of the first two groups each in his own way adopted rigorous attitudes of negation, the one by denying divine authority to all laws incorporated in the Talmud, and the other by negating that negation, and opposing the legitimacy of freedom for critical analysis of such laws as were claimed to have been handed down by Moses along with the written law, the third group adopted a view which was intended to secure an adjustment of tradition with the views of the new science and learning. How far, however, they were prepared to go in that adjustment, they did not determine…
One may, therefore, very conveniently classify these three groups as follows: Extreme right wingers, who jealously guarded every custom and observance handed down to them by their ancestors, lest the complete structure of Judaism tumble; extreme left wingers who tended to undermine the very fundamentals upon which that structure rested; and a central group that believed in the freedom of research and in historical and critical analysis, in consequence of which belief they propounded many advanced views on the origin of the Halacha or at least portions of it.
It would, however, be incorrect for the student to stop there. For it was just at that time that certain Rabbinic scholars of extraordinary distinction produced a viewpoint somewhat different from the above-mentioned. While their orthodoxy was beyond question, it possessed a peculiar flavour, and so they could be identified neither with the ordinary older type nor with the neo-orthodoxy of the scientific school. They were a remarkable blending of old and new. They remained throughout valiant champions and uncompromising adherents of tradition, but they also regarded it as their inescapable duty to initiate investigation into all the sources of halacha which might bear on the authority of the oral laws which were held to be binding for all time. These men were the eminent rabbinic scholars Malbim, Meklenburg, and Zevi Hirsch Chajes, who occupied a special place among their rabbinic contemporaries. While their contemporaries, mentioned above, had a remarkable knowledge of the entire field of Halachic and Aggadic literature, and were also possessed of penetrating minds which delved into many a complicated problem, they nevertheless made no attempt to elucidate the close relationship between the Written and the Oral Law, or to formulate, by analysis and classification, the various categories of Halacha belonging to Torah She-Be-Al Peh, an activity which was to prove so essential at that crucial period in the last century…
 Ezekiel Landau (1713-1793) or Prague, combined vast erudition with great beauty of character. He was one of the first rabbis of his time to trace in the invasion of the Medlessohnian Haskalah a danger to Judaism. Though he did not oppose secular knowledge, he differentiated between secular knowledge and that propounded by the Mendelssohnian school.
 Mordecai Banett, Hungarian Rabbi (1773-1854) of Neutra, of great reputation beyond the limits of his own country for his scrupulous conscientousness, self-effacement, and piety.
 Akiba Eiger (1761-1839) of Posen, universally known for his great Talmudic learning, noble and self-sacrificing character, and idealistic nature. An uncompromising opponent of reform, and a champion of extreme orthodoxy.
 Moses Sofer (1763-1839) of Pressburg, a disciple of Nathan Adler of Frankfurt-on-Main, famous for his Talmudic scholarship, combined with some knowledge of secular sciences, and for his fierce and unremitting warfare against the Reform movement.
 Abraham Geiger (1810-1874) theologian and Reform Rabbi of Frankfurt-on-Main and Berlin, advocate of radical reform ofsJudaism. In his principal work… he claimed to have discovered traces of alterations in the Hebrew text of the Bible, due to changing conceptions in various ages.
 Samuel Holdheim (1806-1860) of Berlin, opponent of Talmudic Judaism and leader of the extreme reform movement in Germany, held extremist views which even the reform rabbis of his day disclaiemed, as constituting a negation of Judaism.
 David Einhorn (b. Bavaria 1809, d. New York 1879) Reform Rabbi and author.
 Isaac Noah Mannheimer (1795-1865), and otustanding preacher and orator in Vienna, wrote on religious reform and political emancipation.
 Leopold Zunz, Jewish German scholar (1794-1886) regarded as the founder of the modern science of Judaism. His [book] was among the most important Jewish works published in the nineteenth century.
 Nachman Krochmal (1785-1840), Galician Jewish philosopher and historian, who paved the way for the critical study of Jewish history. His only work Moreh Nebukhe ha-Zeman, the result of careful study, touches upon the profoundest problems of Jewish science.
 Solomon Judah Leib Rappaport (1790-1867) of Prague, Rabbi and scholar, renowned for his critical investigations. He excelled all his contemporaries in the establishment of historical dates.
 Zacharia Frankel (1801-1875) President of the Breslau Seminary, Germany, an eminent exponent of the rationalistic view of history and a great advocate of freedom of research. His attitude regarding Sinaitic laws was that they are not of Mosaic origin. Gerenally, however, he was vague on the subject.
 V. supra, p. xviii, note 5.
 Jacob Zevi Meklenburg, Rabbi of Konigsberg (died 1865).