The Geniza gives the pietists back

Judeo-Arabic pietist manuscripts recovered from the Cairo Geniza and edited over the last century — by Goitein, Fenton and others — show that Abraham Maimonides' movement had leaders, texts and continuity for generations after him.

The evidence base under this pack's central claim. Before the Geniza work, the crossing looked like an eccentric footnote; after it, it is a chapter.