Reconstructionist Judaism

Reconstructionism was developed by Rabbis Mordecai Menahem Kaplan (1881–1983) and Ira Eisenstein over a period of time spanning from the late 1920s to the 1940s. It formally became a distinct denomination within Judaism with the foundation of the Reconstructionist Rabbinical Seminary in 1968.

Theology:

Mordecai Kaplan held that in light of the advances in philosophy, science and history, it would be impossible for modern Jews to continue to adhere to many of Judaism's traditional theological claims. Kaplan's naturalism theology has been seen as a variant of John Dewey's philosophy. Dewey's naturalism combined atheist beliefs with religious terminology in order to construct a religiously satisfying philosophy for those who had lost faith in traditional religion.

In agreement with the classical medieval Jewish thinkers, Kaplan affirmed that God is not personal, and that all anthropomorphic descriptions of God are, at best, imperfect metaphors. Kaplan's theology went beyond this, however, to claim that God is the sum of all natural processes that allow man to become self-fulfilled. Kaplan wrote that "to believe in God means to take for granted that it is man's destiny to rise above the brute and to eliminate all forms of violence and exploitation from human society." Most Reconstructionist Jews reject traditional forms of theism.

All Orthodox Jews, most Conservative Jews, and some Reform Jews find Kaplan's theology incompatible with that of classical Judaism. Some within the Reconstructionist movement, while accepting many of Kaplan's other ideas, refused to accept Kaplan's theology. Instead they affirm a theistic view of God.