The first modern-academic historians of Judaism, the "Wissenschaft des Judentums" school of the 19th century, framed Judaism in solely rational terms in the emancipatory Haskalah spirit of their age. They opposed kabbalah and restricted its significance from Jewish historiography. In the mid-20th century, it was left to Gershom Scholem to overturn their stance, establishing the flourishing present-day academic investigation of Jewish mysticism, and making Heichalot, Kabbalistic and Hasidic texts the objects of scholarly critical-historical study. In Scholem's opinion, the mythical and mystical components of Judaism were at least as important as the rational ones, and he thought that they, rather than the exoteric Halakha or intellectualist Jewish philosophy, were the living subterranean stream in historical Jewish development that periodically broke out to renew the Jewish spirit and social life of the community. Scholem's magisterial "Major Trends in Jewish Mysticism" (1941) among his seminal works, though representing scholarship and interpretations that have subsequently been challenged and revised within the field, remains the only academic survey studying all main historical periods of Jewish mysticism