||One of Mendelssohn's major works, a German translation of the Pentateuch, Haftorot, and Five Scrolls in Waberish Hebrew letters. Moses b. Menahem Mendelssohn of Dessau (1729–1786), philosopher of the German Enlightenment in the pre-Kantian period and spiritual leader of German Jewry. Born in Dessau, Mendelssohn during his early childhood suffered from a disease which left him with a curvature of the spine and permanently affected his nervous system. The son of a Torah scribe, Mendelssohn received a traditional Jewish education under the influence of David Fraenkel, who was then rabbi of Dessau. When the latter was appointed rabbi of Berlin in 1743, Mendelssohn followed him there in order to pursue his studies and to acquire a general education. He earned his livelihood with difficulty at the same time studying diligently and acquiring broad education. In addition to his fluent knowledge of German and Hebrew, he became familiar with Latin, Greek, English, French, and Italian. His teachers were young educated Jews, such as Israel M. Zamosz, who taught him mathematics, Abraham Kisch, and A. S. Gumpertz. During this period he met the writer and dramatist G. E. Lessing (1754) and a deep and lifelong friendship developed between them. In 1750 he became a teacher in the house of Isaac Bernhard, owner of a silk factory; in 1754, he was entrusted with the bookkeeping of the factory and eventually he became a partner in the enterprise. During the whole of his lifetime he worked as a merchant, while carrying out his literary activities and widespread correspondence in his free time. Only in 1763 he was granted "right of residence" in Berlin by the king. In 1762, he married Fromet Guggenheim of Hamburg, and they had six children (see Mendelssohn family). In 1754 Mendelssohn began to publish - at first with the assistance of Lessing - philosophical writings and later also literary reviews. In 1763, he was awarded the first prize of the Prussian Royal Academy of Sciences for his work Abhandlung ueber die Evidenz in metaphysischen Wissenschaften. However, when the academy elected him as member in 1771, his election was not ratified by King Frederick II. In 1769, he became embroiled in a dispute on the Jewish religion, and from then on, he confined most of his literary activity to the sphere of Judaism. He was also active on behalf of the Jews in practical affairs. He was as outstanding in his conversation as in his writing, and a circle of intellectuals gathered regularly at his home to discuss general and Jewish subjects. He was famous among both Jews and non-Jews for his wide knowledge, his sharp intellect and his moderate, patient, and modest character. All of his descendants converted to Christianity.
Mendelssohn campaigned for the termination of the Jewish ghettos and the entrance of the Jews as equals into German society, efforts which were aided by his first-ever translation of the Pentateuch into German, and the publication of his political treatise Jerusalem, which argued for religious toleration within the state, and against the control of civil society by religious institutions, based on the idea that religious conscience could not be legislated, and that man's actions must be guided by reason. These arguments formed the basis of the Haskalah (Jewish Enlightenment) movement in Eastern Europe and the Russian Pale of Settlement, which liberated these Jewish communities from the Hasidic rabbinate degraded by cabalism and superstition. Mendelssohn's influence in Germany and America led to the formation of the Jewish Reform movement.