Michael Creizenach (born in Mainz May 16, 1789; died in Frankfort-on-the-Main, August 5, 1842) was a German Jewish educator, mathematician, theologian, and proponent of the Reform movement.
Creizenach was educated in the traditional way, devoting his whole time to Talmudic studies; and he was sixteen years old when he began to acquire the elements of secular knowledge.
In 1825 Creizenach was appointed teacher at the Philanthropin in Frankfort, where he found in I. M. Jost an enthusiastic coworker in pedagogic and reform endeavors.
With this object he wrote his "Shulḥan 'Aruk," in which he essayed to prove that the Talmud as a whole was untenable, but that a compromise with modern ideas could be effected in the same dialectical way in which the Rabbis had harmonized the Law with the exigencies of their time.
In the later parts of his work, however, he abandoned this view; advocating a return to pure Mosaism, which a year after his death was more distinctly proclaimed as the program of the Frankfort Reformverein, at the head of which was his son Theodor Creizenach.