Abraham Geiger (Hebrew: אַבְרָהָם גַיְיגֶר‎ ʼAvrāhām Gayger; 24 May 1810 – 23 October 1874) was a German rabbi and scholar who is considered the founding father of Reform Judaism and the academic field of Quranic studies.

Emphasizing Judaism's constant development through its history and universalist traits, Geiger sought to re-formulate received forms and design what he regarded as a religion compliant with modern times.

As a child, Geiger started doubting the traditional understanding of Judaism when his studies in classical history seemed to contradict the biblical claims of divine authority.

At Bonn, Geiger began an intense study of Arabic and the Koran, winning a prize for his essay, written originally in Latin, and later published in German under the title Was hat Mohammed aus dem Judenthume aufgenommen?

[3] His journals became important vehicles in their day for publishing Jewish scholarship, chiefly historical and theological studies, as well as a discussion of contemporary events.

[4] In the Germany of the 19th century, Geiger and Samuel Holdheim, along with Israel Jacobson and Leopold Zunz, stood out as the founding fathers of Reform Judaism.

Geiger was a more moderate and scholarly reformer, seeking to found this new branch of Judaism on the scientific study of history, without assuming that any Jewish text was divinely written.

Geiger was not only a scholar and researcher commenting on important subjects and characters in Jewish history – he was also a rabbi responsible for much of the reform doctrine of the mid-19th century.

[1] As Geiger grew into his adolescence and young adulthood, he began to establish a more liberal approach to, and understanding of, Judaism than his traditional Orthodox Jewish background dictated.

In 1837, Geiger arranged a meeting of reform-minded rabbis in Wiesbaden for the purpose of discussing measures of concern to Judaism,[1] and continued to be a leader of liberal German rabbinical thought through 1846.

"Ultimately, in 1871, he was appointed to the faculty of the newly founded Reform rabbinical college in Berlin, Hochschule für die Wissenschaft des Judentums, where he spent his final years.