Yeridat ha-dorot

Yeridat ha-dorot (Hebrew: ירידת הדורות), meaning literally "the decline of the generations", or nitkatnu ha-dorot (נתקטנו הדורות), meaning "the diminution of the generations", is a concept in classical Rabbinic Judaism and contemporary Orthodox Judaism expressing a belief in the intellectual inferiority of subsequent, and contemporary Torah scholarship and spirituality in comparison to that of the past. It is held to apply to the transmission of the "Revealed" (nigleh) aspects of Torah study, embodied in the legal and homiletic Talmud, and other mainstream rabbinic literature scholarship. Its reasoning derives from the weaker claim to authoritative traditional interpretation of scripture, in later stages of a lengthening historical chain of transmission from the original revelation of the Torah at Mount Sinai, and the codification of the Oral Torah in the Talmud. This idea provides the basis to the designated Rabbinic Eras from the Tannaim and Amoraim of the Talmud, to the subsequent Gaonim, Rishonim and Acharonim. Additionally, it has an extra metaphysical explanation in Kabbalah, regarding lower levels of souls in succeeding generations.

However, Kabbalah limits the effect of Yeridat ha-dorot only to nigleh. In contrast, the "Concealed" (nistar) aspects of Torah, embodied in Jewish mysticism, are identified with an opposite process of successively higher articulations of mystical thought as the process of history unfolds. The reasoning for this derives from the notion that Jewish mysticism progresses instead from successive new divine revelations to supreme mystics, as the only way to deepen its conceptual structures. This paradoxical dialectic relates in Kabbalistic terminology to descending immanent "Vessels", and successively higher transcendent "Lights" through the history of creation. In Jewish thought, deepening Talmudic and Rationalist enquiry broadens the physical application of Torah (vessels), while deepening Jewish mysticism draws down higher levels of illumination (light).